Symposium
Identifieur interne : 001A71 ( Istex/Corpus ); précédent : 001A70; suivant : 001A72Symposium
Auteurs :Source :
- Nematology [ 1388-5545 ] ; 2002.
Url:
DOI: 10.1163/15685410260099833
Links to Exploration step
ISTEX:0BD3A8C6C218D3B6635974A3ACF56C3CBAEC4EBDLe document en format XML
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Ciano 39, 97014 Ispica (RG), Italy nemang02@area</title></json:item><json:item><author></author><host><author></author><title>Developmental</title><publicationDate>91000</publicationDate></host><publicationDate>91000</publicationDate></json:item><json:item><host><author><json:item><name>Kennedy-Leigh Center</name></json:item><json:item><name>Horticultural Research</name></json:item></author><title>The Hebrew University of Jerusalem, Rehovot, Israel ¤ mgoelln@duke.edu 1 Department of Plant Pathology</title></host></json:item><json:item><host><author></author><title>IA 50011, USA ¤ dputhoff@iastate.edu Cyst nematodes infect and devastate many agricultural crops. After root penetration, cyst nematodes induce the formation of feeding cells (syncytia) within the host roots</title><publicationDate>2002</publicationDate></host></json:item><json:item><host><author><json:item><name>M Sobczak 1 ; ¤</name></json:item><json:item><name>S Fudali 1</name></json:item><json:item><name>B Golecki 2</name></json:item><json:item><name>S Janakowski 1</name></json:item><json:item><name>G Grymaszewska</name></json:item></author></host></json:item><json:item><author></author><host><volume>2630</volume><author></author><title>Rakowiecka</title></host></json:item><json:item><author></author><host><author></author><title>Institute of Phytopathology</title></host></json:item><json:item><author></author><host><volume>7616</volume><author></author><title>Campus Box</title></host><title>Austria ¤ Sobczak@delta.sggw.waw.pl 1 Department of Plant Pathology</title></json:item><json:item><author></author><host><volume>354</volume><pages><last>970</last><first>96001</first></pages><author></author><title>C.P</title></host></json:item><json:item><host><pages><last>970</last><first>70849</first></pages><author><json:item><name>Embrapa </name></json:item><json:item><name>Cp </name></json:item></author></host></json:item><json:item><author></author><host><author></author><title>Embrapa Soja</title></host></json:item><json:item><host><author><json:item><name>Embrapa Arroz</name></json:item><json:item><name>& Feijão</name></json:item></author></host></json:item><json:item><host><pages><last>970</last><first>86001</first></pages><author><json:item><name>Embrapa Meio</name></json:item><json:item><name>Norte </name></json:item></author></host></json:item><json:item><host><author><json:item><name>Iita Ibadan</name></json:item><json:item><name>/ Nigeria</name></json:item><json:item><name>& Lambourn</name></json:item><json:item><name>Carolyn Co</name></json:item><json:item><name> House</name></json:item></author></host></json:item><json:item><host><author></author><title>Kasteelpark Arenberg 13, 3001 Leuven</title><publicationDate>185610</publicationDate></host></json:item><json:item><author><json:item><name>Cralley-Warren Center</name></json:item></author><host><author></author><title>N. 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When methyl bromide (MB) is not used for soil disinfection, nematodes become one of the main soil-borne pathogens. The response of 75 resistant pepper stocks was tested against Phytophthora capsici and M. incognita in relation to nonresistant varieties grown on MB disinfected soils. More than 30% of the stocks assayed had average root-knot index similar to those of MB treatments. More than 30% of the stocks had also marketable yields Stocks grown on the same soil over 3 years led to an increase of aggressiveness in M. incognita populations. This was noticed by an increase in average root-knot index and the percentage of infested plants (i.e., in the 1st year the C-30 hybrid had 0.1% of infested plants and 0.1 of root-knot index, while in the 2nd year 73</title></host></json:item><json:item><host><author><json:item><name>M Garry</name></json:item><json:item><name>P,J Rosewarne ¤</name></json:item><json:item><name>E,S Larkin</name></json:item><json:item><name> Lagudah Plant</name></json:item><json:item><name> Industry</name></json:item><json:item><name>Gpo Csiro</name></json:item><json:item><name> Box</name></json:item></author><title>Identii cation of markers to facilitate cloning of resistance genes to Heterodera trifolii in clover</title><publicationDate>1600</publicationDate></host></json:item><json:item><host><pages><last>900</last><first>70770</first></pages><author><json:item><name>/ Embrapa</name></json:item><json:item><name>C,P Cenargen</name></json:item></author><publicationDate>2372</publicationDate></host></json:item><json:item><author><json:item><name>/ Embrapa</name></json:item><json:item><name> Cnph</name></json:item><json:item><name> Br 060</name></json:item><json:item><name> Km 09 Rod</name></json:item></author><host><author></author><title>Brasilia/Anapolis (70359-970)</title></host></json:item><json:item><host><pages><last>641</last><first>6</first></pages><author><json:item><name>Campo </name></json:item><json:item><name>Rodovia Lmg</name></json:item><json:item><name> Km</name></json:item></author><title>600-000) Paracatu, MG, Brazil 1 CIMMYT, Wheat Program</title></host></json:item><json:item><host><author><json:item><name>Umr Inra</name></json:item><json:item><name>/ Ensar</name></json:item></author></host></json:item><json:item><author></author><host><author></author><title>Faculty of Agriculture, PO Box 12009</title></host></json:item><json:item><host><author><json:item><name>Umr Inra</name></json:item><json:item><name>/ Ensar</name></json:item></author></host></json:item><json:item><host><author><json:item><name>Icarda </name></json:item><json:item><name>Cereal Pathology</name></json:item><json:item><name>Po Box</name></json:item></author></host></json:item><json:item><host><author><json:item><name>Sp Jaboticabal</name></json:item><json:item><name> Brazil</name></json:item></author></host></json:item><json:item><host><author><json:item><name> Univ</name></json:item><json:item><name>– Of Florida</name></json:item><json:item><name> Ifas</name></json:item></author></host></json:item><json:item><author><json:item><name>Florida Dept</name></json:item></author><host><pages><last>7100</last><first>32614</first></pages><author></author><title>Division of Plant Industry</title><publicationDate>147100</publicationDate></host><publicationDate>147100</publicationDate></json:item><json:item><host><author><json:item><name>Florida Department Of Agriculture</name></json:item><json:item><name>Po Dpi</name></json:item><json:item><name> Box</name></json:item></author><publicationDate>147100</publicationDate></host></json:item><json:item><author><json:item><name>Cnr Istituto Nematologia Agraria</name></json:item><json:item><name>/,A Via Amendola 165</name></json:item><json:item><name>Bari </name></json:item></author><host><author></author><title>Italy ¤ inserrr@doacs.state</title></host></json:item><json:item><author></author><host><author></author><title>Nematology Interactions Unit, IACR-Rothamsted</title></host></json:item><json:item><host><author><json:item><name>Cabi Bioscience</name></json:item><json:item><name>Uk Centre</name></json:item></author><title>UK ¤ jarowe@bbsrc.ac.uk 1 Institute of Grassland and Environmental Research</title></host></json:item><json:item><host><author><json:item><name>Macaulay Institute</name></json:item><json:item><name>Craigiebuckler 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Cantoblanco</name></json:item><json:item><name> Madrid</name></json:item><json:item><name>¤ Spain</name></json:item></author></host></json:item><json:item><host><author><json:item><name> Departamento De Geología</name></json:item></author></host></json:item><json:item><host><author><json:item><name> Institute Of Grassland</name></json:item><json:item><name>Plas Research</name></json:item><json:item><name> Gogerddan</name></json:item></author></host></json:item><json:item><host><author></author><title>The Macaulay Institute</title></host></json:item><json:item><author><json:item><name>Netherlands Institute</name></json:item><json:item><name> Ecology</name></json:item><json:item><name>P,O Nioo-Cto )</name></json:item></author><host><pages><first>6666</first></pages><author></author><title>The Netherlands 2 Rothamsted Experimental Station</title></host></json:item><json:item><author></author><host><author></author><title>Institute of Grassland and Environmental Research (IGER), UK 4 Centrum voor Landbouwkundig Onderzoek (CLO), Belgium 5 Institut de Recherche pour le Developpement</title></host></json:item><json:item><author></author><host><author></author><title>The Netherlands 7 Instituto do Mar (IMAR)</title></host></json:item><json:item><host><pages><first>36153</first></pages><author><json:item><name>Estación Fitopatológica 'do</name></json:item><json:item><name> Areeiro</name></json:item></author></host></json:item><json:item><host><pages><first>28006</first></pages><author><json:item><name>Dpto Agroecología</name></json:item><json:item><name>Ccma </name></json:item><json:item><name>Csic </name></json:item></author></host></json:item><json:item><host><author><json:item><name> Madrid</name></json:item><json:item><name>¤ Spain</name></json:item></author></host></json:item><json:item><author></author><host><volume>75</volume><issue>07071</issue><author></author><title>Cra. de Valldemossa km</title></host></json:item><json:item><author><json:item><name>Centro De</name></json:item><json:item><name>Ciencias Medioambientales</name></json:item><json:item><name> Csic</name></json:item><json:item><name> Madrid</name></json:item><json:item><name>¤ Spain</name></json:item></author><host><author></author><title>com 508 Colonial Circle</title></host></json:item><json:item><author><json:item><name> Decanato De Agronomía</name></json:item><json:item><name> Dpto</name></json:item><json:item><name> Biológicas</name></json:item></author><host><volume>400</volume><author></author><title>Apdo</title></host></json:item><json:item><author></author><host><author></author><title>Instituto de Investigaciones Agrícolas (INIA-Zulia). Apdo 1316</title></host></json:item><json:item><author></author><host><author></author><title>Instituto Nacional de Investigaciones Agrícolas, INIA-Zulia, Apdo. 1316</title></host></json:item><json:item><author></author><host><author></author><title>Instituto Nacional de Investigaciones Agrícolas, INIA-Zulia, Apdo. 1316</title></host></json:item><json:item><host><author><json:item><name>Dpto Agroecología</name></json:item><json:item><name>Csic Ccma</name></json:item><json:item><name> Serrano 115 Dpdo</name></json:item></author><publicationDate>28006</publicationDate></host></json:item><json:item><host><author><json:item><name> Servicio Protección Y Sanidad</name></json:item><json:item><name>Estación Vegetal</name></json:item><json:item><name> Sericícola</name></json:item></author></host></json:item><json:item><host><author><json:item><name> Servicio De Investigación Y Desarrollo</name></json:item><json:item><name> Tecnológico</name></json:item><json:item><name> Junta De Extremadura</name></json:item><json:item><name> Finca La Orden</name></json:item><json:item><name> 06187 Guadajira</name></json:item></author></host></json:item><json:item><author></author><host><author></author><title>The Norwegian Crop Research Institute, Plant Protection Centre</title></host></json:item><json:item><author></author><host><volume>44</volume><author></author><title>Dept. of Crop Science Box</title></host></json:item><json:item><author><json:item><name>Ppi Iacr-Rothamsted</name></json:item><json:item><name> Division</name></json:item></author><host><author></author><title>Nematode Interaction Unit</title></host></json:item><json:item><host><author><json:item><name>Hiroshima Prefectural Forestry Research Centre</name></json:item></author></host></json:item><json:item><author></author><host><pages><first>14561</first></pages><author></author><title>Benaki Phytopathological Institute</title></host></json:item><json:item><host><author><json:item><name>Greece Ki Ssia</name></json:item></author></host></json:item><json:item><author></author><host><volume>9</volume><author></author><title>Hermann-Rodewald-Str</title></host></json:item><json:item><host><author><json:item><name>Scottish Crop Research</name></json:item><json:item><name> Institute</name></json:item><json:item><name> Invergowrie</name></json:item><json:item><name>Dd2 Dundee</name></json:item><json:item><name> 5da</name></json:item><json:item><name> Scotland</name></json:item><json:item><name> Uk</name></json:item></author></host></json:item><json:item><author></author><host><author></author><title>217 Plant Sciences</title></host></json:item><json:item><author></author><host><volume>2340</volume><author></author><title>P.O. Box</title></host></json:item><json:item><host><author></author><title>Arkansas Cooperative Extension Service</title></host></json:item><json:item><author><json:item><name> Laboratorio De Nematología</name></json:item></author><host><author></author><title>Centro de Zoología Aplicada</title></host></json:item><json:item><host><author><json:item><name>Estación Experimental Regional Agropecuaria Rama</name></json:item><json:item><name>C,C Caída</name></json:item></author></host></json:item><json:item><host><author><json:item><name>Dpto Agroecología</name></json:item><json:item><name>Csic Ccma</name></json:item><json:item><name> Serrano 115 Dpdo</name></json:item></author><publicationDate>28006</publicationDate></host></json:item><json:item><author><json:item><name> Orientación Morfología</name></json:item><json:item><name> Vegetal</name></json:item></author><host><volume>3</volume><issue>5800</issue><author></author><title>Agencia Postal N ±</title></host><title>Facultad de Ciencias Exactas, Físico-Químicas y Naturales</title></json:item><json:item><author><json:item><name> Laboratorio De Nematología</name></json:item></author><host><volume>122</volume><issue>5000</issue><author></author><title>C.C</title></host></json:item><json:item><author></author><host><author></author><title>Life Sciences Program, Dynamac Co</title></host><title>Kennedy Space Center, FL 32899, USA ¤ Tpowers@unlnotes</title></json:item><json:item><author><json:item><name>Kawanda Agricultural Research</name></json:item><json:item><name>P,O Institute</name></json:item></author><host><volume>7065</volume><author></author><title>Box</title></host></json:item><json:item><author><json:item><name>P,O Ltd</name></json:item><json:item><name> Box</name></json:item></author><host><volume>258</volume><author></author><title>Institute of Ecology and Biological Resources</title></host></json:item><json:item><host><author><json:item><name>Ras Institute Of Parasitology</name></json:item><json:item><name>Leninskii Prospect</name></json:item></author></host></json:item><json:item><author><json:item><name> Agricultural Research</name></json:item><json:item><name> Center</name></json:item></author><host><author></author><title>Van Gansberghelaan 96</title><publicationDate>2002</publicationDate></host><title>Burrowing nematodes associated with durian (Durio zibetinus ), coffee (Coffea spp:/, banana (Musa paradisiaca var. sapientum), rambutan (Nephelium lappacium) and avocado (Persae americana) have been recently recorded in Western Highland Vietnam. The nematodes are widely distributed on durian orchards and coffee plantations;only a few specimens were extracted from root samples of banana, avocado and rambutan. In the infected regions, Radopholus was not detected on corn (Zea mays), black pepper (Piper nigrum), mango (Mangifera indica), citrus (Citrus spp.), pineapple (Ananas sativa), sugarcane (Saccharum off cinarum) and papaya (Carica papaya) Nematodes caused decline and death of trees in many durian nursery gardens and newly replanted orchards. Nematode densities reached several thousands of individuals per g for root samples. Nematodes also induced some damage in coffee plantations(C. arabica and C. robusta) Morphological and morphometrical comparisons of all nematode stages revealed only slight differences between Radophulus populations from durian and coffee and rom R</title><publicationDate>2002</publicationDate></json:item><json:item><host><author><json:item><name>International Wheat</name></json:item><json:item><name>Maize Improvement Center</name></json:item></author></host></json:item><json:item><host><author><json:item><name>Umr Inra</name></json:item><json:item><name>/ Ensar</name></json:item></author></host></json:item><json:item><author></author><host><volume>17</volume><issue>26001</issue><author></author><title>ANADOLU Agricultural Research Institute PK</title></host></json:item><json:item><author></author><host><author></author><title>Plant Protection Institute</title></host></json:item><json:item><author></author><host><author></author><title>Bahri Dagdas MIKHAM</title></host></json:item><json:item><author></author><host><author></author><title>Turkey 7 International Centre Arid Research Dryland Agriculture (ICARDA)</title></host></json:item><json:item><author></author><host><author></author><title>Laboratory of Community Structure and Dynamics, Institute for Problems of Ecology and Fvolution</title></host></json:item><json:item><author><json:item><name>Instituto Nacional De Investigaciones Agrícolas</name></json:item><json:item><name> Inia-Zulia</name></json:item></author><host><author></author><title>Apdo 1316</title><publicationDate>2002</publicationDate></host><publicationDate>2002</publicationDate></json:item><json:item><host><pages><first>3000</first></pages><author><json:item><name> University Of Hawaii</name></json:item><json:item><name>Maile Peps</name></json:item><json:item><name> Way</name></json:item><json:item><name> Honolulu</name></json:item><json:item><name> Hi</name></json:item></author><publicationDate>1910</publicationDate></host></json:item><json:item><host><author><json:item><name>Nioo </name></json:item><json:item><name>Dept </name></json:item><json:item><name>Multitrophic Interactions</name></json:item><json:item><name> Boterhoeksestraat</name></json:item><json:item><name>P,O 48</name></json:item></author><title>Box 40, 6666 ZG, Heteren, The Netherlands c_schreck_reis@mail</title></host></json:item><json:item><author><json:item><name>Embrapa </name></json:item><json:item><name>Recursos Genéticos E Biotecnologia</name></json:item><json:item><name>P,O </name></json:item></author><host><volume>2372</volume><pages><last>970</last><first>70849</first></pages><author></author><title>Box</title></host></json:item><json:item><host><author></author><title>QS 07-Lote 01 (72022-900) Taguatinga Sul, DF</title></host></json:item><json:item><host><author><json:item><name>Development South Australian Research</name></json:item><json:item><name>Gpo Institute</name></json:item><json:item><name> Box</name></json:item></author></host></json:item><json:item><author></author><host><volume>9030</volume><pages><last>9030</last><first>00681</first></pages><author></author><title>P.O. Box</title><publicationDate>29053</publicationDate></host><title>¤ wacewanj@yahoo.com 1 Department of Crop Protection</title><publicationDate>29053</publicationDate></json:item><json:item><host><author><json:item><name>Protección Vegetal</name></json:item><json:item><name>Centro De Investigación Y Desarrollo</name></json:item><json:item><name>Caama Agroalimentario</name></json:item><json:item><name>C Mayor</name></json:item></author></host></json:item><json:item><host><pages><last>002</last><first>30</first></pages><author><json:item><name>Fecoam Consejería De Agricultura</name></json:item><json:item><name>Agua </name></json:item><json:item><name>Medio,C Ambiente</name></json:item><json:item><name> Caballero</name></json:item></author></host></json:item><json:item><author></author><host><pages><last>701</last><first>200</first></pages><author></author><title>Division of Horticultural Environment, National Horticultural Research Institute Suwon 441-440</title></host></json:item><json:item><author><json:item><name>Clima Embrapa</name></json:item><json:item><name> Temperado</name></json:item></author><host><volume>403</volume><pages><last>970</last><first>96001</first></pages><author></author><title>C.P</title></host></json:item><json:item><author></author><host><volume>3</volume><author></author><title>Albert-Einstein-Str</title></host><title>Depto Fitopatologia, 36571-000, Viçosa-MG, Brazil ¤ cbauer@cpact.embrapa.br 1 Institute of Plant Diseases</title></json:item><json:item><author><json:item><name>P,O Centro De Ingeniería Genética Y Biotecnología</name></json:item></author><host><volume>387</volume><author></author><title>Box</title></host></json:item><json:item><author><json:item><name>P,O Centro De Ingeniería Genética Y Biotecnología</name></json:item></author><host><volume>387</volume><author></author><title>Box</title></host></json:item><json:item><host><author><json:item><name>Usda </name></json:item><json:item><name>Ars </name></json:item><json:item><name>Nematology Laboratory</name></json:item><json:item><name>011a Bldg</name></json:item><json:item><name>165b Rm</name></json:item><json:item><name>Barc-West </name></json:item></author></host></json:item><json:item><author></author><host><volume>88</volume><author></author><title>Federal Biological Research Center</title></host></json:item><json:item><author></author><host><volume>67</volume><author></author><title>Cognis Deutschland</title></host></json:item><json:item><author><json:item><name>P,O Centro De Ingeniería Genética Y Biotecnología</name></json:item></author><host><volume>387</volume><author></author><title>Box</title></host></json:item><json:item><host><author></author><title>Cuba ¤ eulogio.pimentel@cigbcam. cigb.edu.cu 1 Institute of Parasitology of Russian Academy of Sciences</title></host></json:item><json:item><author></author><host><author></author><title>Moscow, Russia ¤ nd_romanenko@mail.ru 1 Department of Nematology, Agricultural Research Organization (ARO)</title></host><title>The Volcani Center</title></json:item><json:item><author><json:item><name> Centro De Investigación Y Estudios Avanzados</name></json:item></author><host><author></author><title>Plant Biotechnology and Genetic Engineering Unit</title></host></json:item><json:item><host><author></author><title>Institute of Parasitology, Russian Academy of Sciences, Leninskii pr</title></host></json:item><json:item><host><author><json:item><name>Bakh Institute</name></json:item><json:item><name>Ras Biochemistry</name></json:item><json:item><name>Leninskii,Pr </name></json:item></author><publicationDate>119071</publicationDate></host></json:item><json:item><author><json:item><name>P,O Centro De Ingeniería Genética Y Biotecnología De Camagü</name></json:item></author><host><volume>387</volume><issue>70100</issue><author></author><title>Box</title></host></json:item><json:item><host><author><json:item><name>Fecoam-Consejería De Agricultura</name></json:item></author></host></json:item><json:item><host><pages><last>4</last><first>9</first></pages><author><json:item><name>Protección Vegetal</name></json:item><json:item><name>Cida </name></json:item><json:item><name>Consejería De Agricultura La Alberca</name></json:item><json:item><name>¤ Spain</name></json:item><json:item><name> Alfredo</name></json:item><json:item><name> Lacasa@carm</name></json:item></author><title>es In pepper glasshouses of the Southeast of Spain, Meloidogyne incognita and Phytophthora capsici are the main soil pathogens Methyl bromide (MB 98:2) has been used for soil-borne pathogens in the last 17 years. The mixture 1,3-dichloropropene (60.5%) and chloropicrin (33.3%) (Telopic EC) applied with PE plastic at 50 g/m 2 by drip irrigation was assayed as an alternative to methyl bromide nematode control. In nine of the assays carried out since 1998 no signii cant differences were found Telopic EC and methyl bromide in M. incognita average root-knot index (Telopic: root-knot index D 0 MB: root-knot index D 0.5) However, the proportion of M. incognita infested plants (21.1%) on the mixture treatments was signi cantly higher than that of MB (5.1%) When application was repeated, marketable yield and plant growth at the 3rd year were similar but root</title></host></json:item><json:item><host><author></author><title>Chemical options for the management of Heterodera schachtii in sugar beet under eld conditions Saad L</title></host></json:item><json:item><host><author><json:item><name>Protección Vegetal</name></json:item></author></host></json:item><json:item><host><pages><first>30003</first></pages><author><json:item><name>Fecoam-Consejería De Agricultura</name></json:item><json:item><name>Agua </name></json:item><json:item><name>Medio Ambiente</name></json:item><json:item><name>C Caballero</name></json:item></author></host></json:item><json:item><author><json:item><name>Producción Agraria</name></json:item><json:item><name>Etsia </name></json:item><json:item><name>Universidad Politécnica De Cartagena</name></json:item></author><host><author></author><title>Paseo Alfonso XIII</title></host></json:item><json:item><host><author><json:item><name>S,A Dow Agrosciences Iberica</name></json:item><json:item><name>/ Cerro De Castañar</name></json:item><json:item><name>72b Madrid</name></json:item></author></host></json:item><json:item><author><json:item><name>/ Escola De Agronomia</name></json:item><json:item><name>Campus Ufg</name></json:item><json:item><name> Samambaia</name></json:item></author><host><volume>131970</volume><author></author><title>Caixa Postal</title></host></json:item><json:item><host><author><json:item><name>Jalles Machado</name></json:item><json:item><name>S,A </name></json:item><json:item><name>Fazenda São Pedro S / N</name></json:item><json:item><name>Go-080 Rodovia</name></json:item></author><title>Zona Rural, Caixa Postal 04, CEP 76380-000</title></host></json:item><json:item><host><author><json:item><name>Upc </name></json:item><json:item><name>Comte </name></json:item></author></host></json:item><json:item><author></author><host><author></author><title>08348 Cabrils</title></host><title>Spain ¤ francesc.xavier.sorribas@upc.es 1 University of Hawaii at Manoa, Dept of Plant and Environmental Protection Sciences</title></json:item><json:item><host><author><json:item><name>Beaumont Agricultural Research Center</name></json:item><json:item><name>W Lanikaula</name></json:item><json:item><name> Street</name></json:item></author></host></json:item><json:item><host><author><json:item><name>Canfrm </name></json:item><json:item><name>University Hawaii</name></json:item><json:item><name>W Hilo</name></json:item><json:item><name> Kawili</name></json:item><json:item><name> Street</name></json:item></author></host></json:item><json:item><host><pages><first>28006</first></pages><author><json:item><name>Dpto Agroecología</name></json:item><json:item><name>Csi Ccma</name></json:item><json:item><name> Serrano 115 Dpdo</name></json:item></author></host></json:item><json:item><host><pages><first>38589</first></pages><author><json:item><name>Spain Madrid</name></json:item></author></host></json:item><json:item><host><author><json:item><name>Santa Arico</name></json:item><json:item><name> Cruz</name></json:item><json:item><name> Tenerife</name></json:item></author></host></json:item><json:item><author><json:item><name>Dpto Agricultura</name></json:item><json:item><name>W Rel-Uita</name></json:item><json:item><name> Ferreira Aldunate</name></json:item></author><host><volume>11100</volume><author></author><title>C.P</title><publicationDate>1229</publicationDate></host><publicationDate>1229</publicationDate></json:item><json:item><host><author><json:item><name>Dpto Agroecología</name></json:item><json:item><name>Csic Ccma</name></json:item><json:item><name> Serrano 115 Dpdo</name></json:item><json:item><name> Madrid</name></json:item></author></host></json:item><json:item><author><json:item><name>Scottish Crop Research</name></json:item><json:item><name> Institute</name></json:item><json:item><name>Dd2 Dundee</name></json:item><json:item><name> 5da</name></json:item><json:item><name>Uk Scotland</name></json:item></author><host><author></author><title>Bioinformatics and Statistics Scotland</title></host></json:item><json:item><host><author><json:item><name>Protección Vegetal</name></json:item></author></host></json:item><json:item><host><pages><first>30</first></pages><author><json:item><name>Fecoam Consejería De Agricultura</name></json:item><json:item><name>Agua </name></json:item><json:item><name>Medio Ambiente</name></json:item><json:item><name>C Caballero</name></json:item></author></host></json:item><json:item><author><json:item><name> Dpto De Agroecología</name></json:item><json:item><name> Madrid</name></json:item><json:item><name>¤ Spain</name></json:item><json:item><name> Alfredo</name></json:item></author><host><author></author><title>Lacasa@carm.es 1 CSIRO Entomology</title></host></json:item><json:item><author></author><host><author></author><title>The Norwegian Crop Research Institute</title></host></json:item><json:item><author></author><host><volume>125</volume><author></author><title>Vestfjordens Avløpsselskap</title></host></json:item><json:item><author><json:item><name>Instituto Nematology 1</name></json:item><json:item><name> Biológico</name></json:item></author><host><volume>70</volume><pages><last>970</last><first>13001</first></pages><author></author><title>Caixa Postal Brazil</title></host></json:item><json:item><author></author><host><pages><last>900</last><first>13418</first></pages><author></author><title>Escola Superior de Agricultura 'Luiz de Queiroz', Caixa Postal 09</title></host></json:item><json:item><host><pages><last>000</last><first>13820</first></pages><author><json:item><name>Embrapa Meio</name></json:item><json:item><name>Ambiente </name></json:item></author><title>Caixa Postal 69</title></host></json:item><json:item><host><author><json:item><name>Development South Australian Research</name></json:item><json:item><name>Gpo Institute</name></json:item><json:item><name> Box</name></json:item></author></host></json:item><json:item><host><pages><first>41089</first></pages><author><json:item><name> Minnipa Agricultural</name></json:item><json:item><name> Centre</name></json:item><json:item><name> Box 31</name></json:item><json:item><name> Minnipa</name></json:item><json:item><name>South 5654</name></json:item><json:item><name> Australia</name></json:item><json:item><name>¤ Australia</name></json:item></author></host></json:item><json:item><host><author><json:item><name>Cifa Málaga</name></json:item><json:item><name>Cap-Junta De Andalucía</name></json:item><json:item><name> 29140 Churriana</name></json:item></author></host></json:item><json:item><host><author><json:item><name>Cifa Las Torres-Tomejil</name></json:item><json:item><name>Cap-Junta De Andalucía</name></json:item><json:item><name> Moguer</name></json:item></author></host></json:item><json:item><host><author></author><title>Vanemuise 46, Tartu, Estonia ¤ heta@ph.eau.ee Four eld isolates of Oesophagostomum spp. were collected from Estonian pig farms in 1997 and used for inoculation of eight 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<p>Nematology , 2002, Vol. 4(2), 123-314 Symposium abstracts 001 Bursaphelenchus xylophilus and B. mucronatus in Japan: where are they from? Hideaki I WAHORI 1 ; ¤ , Natsumi K ANZAKI 2 and Kazuyoshi F UTAI 2 1 National Agricultural Research Center for Kyushu Okinawa Region, Nishigoushi, Kumamoto 861-1192, Japan 2 Kyoto University, Kyoto 606-8502, Japan ¤ iwahori@affrc.go.jp Geographical distribution and speciation of Bursaphelen- chus xylophilus (pinewood nematode) and B. mucrona- tus were inferred from molecular phylogenetic analysis and chromosomal number. Several isolates of B. xylop- hilus and B. mucronatus in Japan and from some other countries were used for DNA sequencing of the ITS re- gions in ribosomal DNA. Published research on the num- ber of chromosomes of selected isolates was used to iden- tify a relationship in speciation of these nematodes. We identi ed three (or four) groups of B. xylophilus and two groups of B. mucronatus based on molecular phylogenetic information. These groups corresponded to differences in chromosomal number. We hypothesised a route of geo- graphical migration and speciation of these two nema- todes by estimating the chronology of speciation. The re- sults support a previous hypothesis that B. xylophilus and B. mucronatus diverged with the separation of the Euro- pean and North American continents. In conclusion, our results con rmed that Japanese B. xylophilus was intro- duced recently to Japan ( ca 100 years ago) from North America, and suggested that both Japanese B. xylophilus and B. mucronatus might have two origins in North Amer- ica and Eurasia, respectively. 002 Molecular taxonomy as a method for describing populations and species within the pinewood nematode species complex Robert I. B OLLA Department of Biology, Saint Louis University, 3507 Laclede, St. Louis, MO 63103-2010, USA bollari@slu.edu Shipment of untreated pinewood from North America and several Asian countries into Europe has been banned. This ban has arisen because of the potential for introduction of species of Bursaphelenchus pathogenic to pine into Europe with the consequent effect comparable to that seen in Japan, China and Korea. This ban is based on the lack of identi cation of Bursaphelenchusxylophilus in Europe until the recent identi cation in Portugal. It is felt that if introduced the nematode would establish populations or interbreed with endemic non-virulent species. This ban has had major consequenceson the North American forest industry. Recently many new species of Bursaphelenchus have been described from dead or dying pines throughout Europe. Because morphological characters are limited in usefulness for species descriptions and cannot be used to differentiate populations, molecular taxonomy has become important. We will look at the accuracy of methods used for species identi cation and at what criteria might be used to de ne and differentiate species of Bursaphelenchus when considering import and export bans. 003 Mitigating the pinewood nematode and its vectors in transported coniferous wood David D WINELL USDA Forest Service, 320 Green St., Athens, GA 30602, USA ldwinell@fs.fed.us The pinewood nematode ( Bursaphelenchus xylophilus ) (PWN) has been intercepted in pine chips, unseasoned lumber and packing-case wood. Likewise, PWN insect vectors, Monochamus spp., have been found in pallets, crates, and dunnage. As a result of these interceptions and the known consequences of the introduction of the PWN, many countries regulate the import of coniferous wood. Science-based procedures are needed to ensure that globally transported wood is free of the PWN and its vectors. Mitigation measures that have been investigated include prevention, host selection, and treatment by fumigation, irradiation, chemical dips, pressure treatment with preservatives, and elevated temperature. A mill certi cation program for lumber (no bark, no grub holes) is rational, but has not got much support. Air-drying wood to its equilibrium moisture content will eliminate the PWN. Switching to hardwood lumber for wood packing material is a short-term solution. Irradiation and dipping wood in borates have shown little promise. The ef cacy of pressure-treating green pine lumber with chromated copper arsenate has been shown. Pine chips can be fumigated with phosphine.Logs, lumber, and wood packing material can be fumigated with methyl bromide. Heating coniferous wood to a core temperature of 60 ± C will eradicate the PWN and its vectors. © Koninklijke Brill NV, Leiden, 2002 123</p>
<p>Epidemiology of Pine Wilt disease (1-7) and Plenary Session (8) 004 Occurrence of the pinewood nematode, Bursaphelenchus xylophilus in Portugal and perspectives of the disease spread in Europe Manuel M OTA NemaLab, ICAM, Dept. de Biologia, Universidade de Évora, 7000 Évora, Portugal mmota@uevora.pt In 1999, the pinewood nematode (PWN), Bursaphelen- chus xylophilus, was found and identi ed for the rst time in Portugal and in Europe. Following detection, Por- tuguese authorities initiated the implementation of erad- ication measures during 1999 and 2000, following an alert provided to European Community of cials; as a re- sult, the nematode was con rmed to be con ned in the Setúbal region, near Lisbon. A task force from the follow- up group (GANP) created by the Secretary of State for the Rural Development established a national eradication programme (PROLUNP) to i ) contain PWN within the initial geographic limits; ii ) implement eradication mea- sures; and iii ) monitor PWN at a national level. Research is presently being conducted both at universities as well as research institutes, focusing on the characterisation of Bursaphelenchus species associated with maritime pine, as well as on the insect vector, Monochamus galloprovin- cialis . Recent reports indicate that the nematode may be present in Siberia (Russia), which would present a threat to Eastern European forestry. Efforts are presently being developed by several European countries to establish a re- search consortium to detect and study the possible pres- ence of PWN, for a new PRA. A recent workshop held in Portugal in 2001 was an opportunity for sharing expe- riences and techniques on detection and control. There is clearly a greater awareness of this issue in Europe. 005 Mathematical models for spatial pattern of the spread of pine wilt disease Nanako S HIGESADA 1 ; ¤ , Yukie M IMURA 1 , Fugo T AKASU 1 , Kohkichi K AWASAKI 2 and Kazumi T OGASHI 3 1 Nara Women’s University, Kita-Uoya Nishimachi, Nara 630-8506, Japan 2 Doshisha University, Kyo-Tanabe 610-0321, Japan 3 Hiroshima University, Hiroshima 793-8521, Japan ¤ sigesada@ics.nara-wu.ac.jp An epidemic of pine wilt disease has been spreading in wide areas of Japan for nearly a century. The disease is caused by the pinewood nematode, Bursaphelenchus xylophilus , with the pine sawyer, Monochamus alternatus , as vector. We present a mathematical model to describe the host-parasite interaction between pines and pine sawyers carrying nematodes on the basis of detailed data taken from the incidence of pine wilt disease at a study site located on the northwest coast of Japan. With this model we simulate the temporal change in the incidence of the disease and predict how the epidemic could be controlled by eradication of the pine sawyer. Furthermore, the model is extendedto study the spatial spread of disease on a large scale, by incorporating short-range dispersal of the pine sawyer, together with long-range dispersal through air convection or transportation of logs infested with nematodes. We estimate that more than 10% of sawyers undergo long-distance dispersal in areas where rapid spread of the disease is observed. 006 Fluctuation in genetic structure and virulence of pinewood nematode in host pine trees and insect vectors at the end of a pine wilt epidemic Katsumi T OGASHI 1 ; ¤ , Sachie E NOKI 1 , Yuji I SAGI 1 and Takuya A IKAWA 2 1 Faculty of Integrated Arts and Sciences, Hiroshima University, Kagamiyama 1-7-1, Higashi-Hiroshima 739-8521, Japan 2 Forestry and Forest Products Research Institute, Kukisaki, Ibaraki 305-8687, Japan ¤ togashi@hiroshima-u.ac.jp The pinewood nematode, the causative agent of pine wilt disease, is harboured as a subpopulation in each dead pine tree and then in each vector beetle of Monochamus alternatus in Japan. The transmission is limited during early and mid-summer. To determine a temporal change in genetic structure and virulence of pinewood nematode, the nematode was sampled from dead Pinus densi ora trees and from M. alternatus beetles appearing in a P. densi ora stand between 1996 and 1998 after a heavy infestation. Alleles of 30 nematodes from each sample were determined for four microsatellite loci. A nematode isolate was established from each sample and inoculated on 30 P. densi ora seedlings to determine the virulence. Consequently, the gene frequency was similar between a nematode subpopulationin a dead tree and those in beetles emerging from it in many cases. Average gene diversity between nematode subpopulations was smaller than the average gene diversity within subpopulations. Genetic distance between nematode subpopulations harboured in beetles emerging from the same trees was often smaller 124 Nematology</p>
<p>Symposium abstracts than that between those from different trees. The virulence of nematode was low. Multiple infection may not induce a large variation of virulence including high virulent strains at the end of infestation. 007 Nematode candidates for the biological control of pine wilt disease Hajime K OSAKA Forest Microbiology Division, Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan hkosaka@ffpri.affrc.go.jp Environmentally friendly control methods are being demanded for pest control. There is undoubtedlythe same demand for the control of pine wilt disease. The disease is caused by the pine wood nematode, Burusaphelenchus xylophilus , which is transmitted by the Japanese pine sawyer, Monochamus alternatus . In this presentation, recent studies on three kinds of bene cial nematodes are reported for the biological control of the disease; the entomopathogenic nematodes, Steinernema spp.; the tylenchid insect parasitic nematode, Controtylenchus genitalicola ; and avirulent isolates of B. xylophilus . Steinernematids can kill the vector insects in the dead pine logs by spraying nematode suspension on the surface of logs. Controtylenchus genitalicola has the potential to reduce the fecundity of the vector insects and propagates by feeding on a fungus as well as in the host insects. This mycetophagy could allow mass production of the nematodes. Avirulent isolates of B. xylophilus can induce the resistance of pine trees against the disease by inoculation of pine trees with the nematodes. However, there are also many barriers to develop the practical control of the disease using these nematodes. The direction of further studies to cross these barriers is discussed. 008 Suppressiveness of soils against pathogens: biodiversity and nematology R. R ODRIGUEZ -K ABANA Department of Entomology & Plant Pathology, Auburn University, Auburn, AL 36849, USA rrodrigu@acesag.auburn.edu Scienti c recognition of the existence of soils suppressive of plant diseases is over a century old and was based originally on the Fusarium -root-knot complex in Alabama cotton elds. Prior to this, researches into the phenomenon of ‘tired soils’ [ Boden Muedigkeit ] in Germany led to the isolation of fungal species from within cysts and females of Heterodera schachtii from sugarbeet elds. It was thought then that some of these fungi were pathogens of the nematodes. Throughout the 20th century additional examples of soils suppressive to other pathogens were described. This led to the idea that the phenomenon of suppressiveness was linked to the presence of one or a limited number of microbial species antagonistic to the pathogens. Research efforts during the century led to the successful development of several schemes and cultural practices that generate or increase suppressiveness of soils against individual pathogens. These efforts evidenced that the phenomenon of suppressiveness is closely linked with biological diversity of soils. Also, that suppressiveness or ‘resistance’ of soils against pathogens is a continuum. It is demonstrable that a soil severely affected by disease can be converted gradually into a suppressive soil where disease incidence becomes unimportant. There are in soils degrees of ‘resistance’ against pathogens. Non- phytopathogenic nematodes play an integral role in the phenomenon of suppressiveness of soils against plant pathogens. These nematodes can be directly active against pathogens and can also disseminate microbial species throughout the soil and increase microbial activity, hence ‘resistance’ to pathogens. 009 Molecular diagnostics: going towards new frontiers C. André L EVESQUE Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Centre, K.W. Neatby Building, 960 Carling Avenue Ottawa, ON, K1A 0C6, Canada LevesqueCA@em.agr.ca Molecular diagnostic tests developed and used in the past few decades have been relying on antibodies for techniques such as ELISA and on DNA based assays, in particular PCR. A new revolution is in the making which is generated by the synergy between genomics and microfabrication, two of the most important research elds worldwide. Genomics tools can already be tapped directly for environmental research by using existing DNA microarrays, e.g ., a gene expression pro le of a soil sample can be determined by using bacterial microarrays. Several molecular and computer companies have made ‘bio-chip’ and are already producing a completely new generation of instruments for the life sciences. It is already Vol. 4(2), 2002 125</p>
<p>Molecular diagnostics (9-13) possible to combine all the steps of complex molecular biology protocols within devices of the size of a credit card. The competition is erce to see which company will come up with the rst hand-held device to perform standard molecular diagnostic tests for genetic disorders or infectious diseases at the point of care. The competitive research on these molecular diagnostic devices is going at a fast pace which has been accelerated further by recent bioterrorism events. In the near future, soldiers are likely to carry specialised miniature molecular diagnostic labs as part of their equipment against biological warfare. When DNA or biomolecules meet the microchip in silica , the possibilities are endless and science ction movies might be outdone soon. 010 Progress in developing nematode diagnostics Vivian C. B LOK Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK vblok@scri.sari.ac.uk Distinguishing pathogenic nematodes at the species or subspecies levels is relying increasingly on molecular tools. Morphological differences may be absent or dif - cult to observe. PCR-based diagnostics offer possibilities for precision, sensitivity and quanti cation. For example, ribosomal DNA has been widely exploited to distinguish many species of plant-parasitic nematodes, to investigate intraspeci c variation and to examine evolutionary rela- tionships. Further re nements are in progress to use rDNA to quantify and determine the relative proportions in mix- tures of species for use in risk assessments. Mitochondrial DNA size polymorphisms have also been used to distin- guish many of the economically important root-knot ne- matodes; however, for many genera this molecular target remains unexplored or may be problematic. Where the ‘conventional’ targets have lacked suf cient variability to distinguish closely related species, randomly ampli ed polymorphismsfrom ngerprintingpatterns have been ex- ploited. Challenges remain, however. Honing molecular diagnostics to distinguish between pathogenic and non- pathogenicvariants within species will require identifying molecular targets which are either closely linked to or de- ne the functional pathogenicity. Incorporating diagnos- tics into management programmes to more effectively de- ploy resistance, pesticide use or crop rotation will require improving the simplicity, reproducibility and portability of these diagnostics to encourage their uptake. 011 Real time PCR for quantitative detection John M ARSHALL , Sandi K EENAN and Simon B ULMAN New Zealand Institute for Crop & Food Research Ltd, Private Bag 4704 Christchurch, New Zealand Marshallj@crop.cri.nz PCR assay for the simultaneous detection and identi - cation of Globodera rostochiensis and G. pallida (PCN) has been developed but cannot be used to determine the level of infestation in the soil as the standard PCR sig- nal is not quantitative. Direct single step quantitative de- tection is possible using Taqman technology as the inten- sity of the uorescent signal generated during the PCR reaction is quantitative. Using this system, simultaneous detection and quanti cation of the target DNA of both G. rostochiensis (Ro) and G. pallida (Pa) was optimised. Quantitative PCR of PCN DNA template concentrations demonstrated that pure DNA from both Ro and Pa gave regression co-ef cient of the standard Ct curve against template concentration on average better than 0.95. This result was repeated using second stage juvenile individu- als and whole PCN cysts. Duplex primers for Ro and Pa were developed and we were able to detect both species and also determine the ratio of both species in the mix- ture. Other applications of this technology, problems and limitations will be discussed. 012 Quantifying nematodes and other root diseases in the Australian wheat belt John C URRAN CSIRO Entomology P.O. Box 1700, Canberra ACT 2601, Australia john.curran@csiro.au Root lesion and cereal cyst nematodes are the major plant- parasitic nematodes to infest grain crops in Australia. They rarely occur in isolation and several major fungal pathogens such as take-all, Rhizoctonia and crown rot contribute to signi cant soil borne disease. A comprehensive testing system has been developed that quanti es DNA extracted from soil using a plate based hybridisation assay to identify the major pathogens present in a pooled soil sample. This data is then fed into a Decision Support System that takes into account the pathogen levels, environmental and other agronomic factors and provides advise on risk categories to growers. 126 Nematology</p>
<p>Symposium abstracts 013 Nematodes, quarantine pests and pathogen detection using rapid automated sampling of bulk cargo shipments Shimon B AREL 1 ; ¤ , Sam S. B UECHLER 2 and Colin C. F LEMING 3 1 Ministry of Agriculture, National Residue Control Labs NRCL-KVI, P.O. Box 12 Bet Dagan, Israel 2 RAY Detection Technologies, Holon, Israel 3 DANI Department of Agriculture & Rural Development Northern Ireland and The Queen’s University of Belfast, UK ¤ barelshi@ netvision.net.il Nematodes are usually not evenly dispersed. Therefore, testing of bulk cargo for the presence of nematodes is only as good as the methodology and sampling strat- egy applied. Limiting factors for taking lots of samples are the produce bulk size, laborious and costly process- ing. While there have been signi cant advances in pro- cedures for invertebrate pest identi cation, the method- ology and tools for sampling these organisms are less well developed. Effective sampling procedures are criti- cal to successful implementation of quarantine measures. The Discovery ™ CERT technology was originally devel- oped by RAY for detection of explosives and chemical- biological warfare agents in bulk luggage, mail and cargo. Inspection process lasts 8 min for an ULD aviation pal- let 2449 kg checked as a whole in one batch. The sys- tem allows selective collection of ultra trace and particles of a distribution size of 0.5-800 ¹ m. Tests carried out by DANI/ QUB and NRCL using spiked bacterial/fungal and quarantine pests, combinations of invertebrate/substrate e.g. , non-viable nematode cysts ( Globodera rostochien- sis ) placed in boxes, lemons infested by live thrips ( He- liothrips haemorrhoidalis ), specimens of leafminer ( Liri- omyza sativae ) and white y ( Trialeurodes vaporariorum ), inoculated onto bulk cabbages, have shown that Discov- ery ™ can successfully recover the target organisms for identi cation. 014 Precision agriculture: tools of the trade Terry W HEELER Texas Agricultural Experiment Station, Rt. 3, Box 219, Lubbock, TX 79403, USA ta-wheeler@tamu.edu Precision agriculture is the optimisation of management of agricultural crops. Crop management is often affected by physical, chemical, and biological factors which are non-uniform in their impact. Therefore, tools have been developed and are increasingly utilised to manage crops in zones which are smaller than the total eld area. The rst tool was the yield monitor. Yield maps provide growth patterns that may either be consistent over time (often based on soil physical properties), or be variable because of an unusual or sporadic stress. Grid soil sampling for fertility based on global positioning systems (GPS) was another early tool. However, this has been superseded by zone sampling in some areas. Variable rate application equipment has been most heavily utilised in fertiliser application. However, other uses include seeding rates, pesticides, and plant growth regulators. Guidance systems are now used to improve precision of applicationsand row positioning. Precision agriculture is highly dependent on information and its success may depend on the ability to gather inexpensive, yet accurate information. 015 Using electrical conductivity to predict nematode distribution in cotton elds John M UELLER 1 , Ahmad K HALILIAN 1 , Terry K IRKPATRICK 2 , Allen W RATHER 3 and Stephen L EWIS 4 1 Clemson University, 64 Research Rd., Blackville, SC 29817, USA 2 Southwest Research and Education Center, Hope, AR 71801, USA 3 University of Missouri-Delta Center, P.O. Box 160, Portageville, MO 63873, USA 4 108 Long Hall, Clemson University, Clemson, SC 29634, USA Meloidogyne incognita and Hoplolaimus columbus are controlled in cotton by the uniform application of nematicides across a eld. In this system a signi cant portion of the nematicide is applied where nematode densities are below treatment thresholds. This is due to the spatial aggregation patterns these nematode species typically exhibit in agricultural elds. Variable rate applications of nematicide would allow applications only to areas of the eld where treatment thresholds are exceeded. However, generating the nematode distribution maps required for variable rate applications by grid or zone sampling is cost prohibitive. Soil composition, especially percentage of sand, is one of the primary factors in uencing nematode distribution. Soil electrical conductivity(SEC) can predict the sand content of a sandy loam soil with a very high degree of accuracy. A 9% drop in sand content can result in a 57% drop in population densities of H. columbus . Use of a commercially-available SEC meter coupled with a GPS system allows mapping Vol. 4(2), 2002 127</p>
<p>Precision agriculture and GPS (14-17) and Global comparative nematode management (18-26) of a ten ha eld in several hours. These maps can then be used for cost-effective variable rate applications of nematicides. 016 Remote sensing and precision nematicide applications for reniform nematode management in Mississippi cotton G.W. L AWRENCE 1 ; ¤ , A.T. K ELLEY 1 , R.L. K ING 2 , J. V ICKERY 2 , H.K. L EE 1 and K.S. M C L EAN 3 1 Department of Entomology and Plant Pathology Mississippi State University, Mississippi State, MS, USA 2 Department of Electrical and Computer Engineering Mississippi State, MS 39762, USA 3 Department of Entomology and Plant Pathology, Auburn University, Auburn University, AL 36849, USA ¤ glawrence@entomology.msstate.edu Site-speci c management of cotton pests is practised in Mississippi using remote sensing to direct spatially vari- able pesticide applications. Remotely sensed imagery is correlated with crop growth parameters using Normalized Difference Vegetation Index (NDVI) values to create pre- scription maps for bi-modal or multi-modal distributions. This technology is being examined using the spatial dis- tribution of the reniform nematode. Re ectance proper- ties exhibited by reniform-infected cotton plants are be- ing acquired with hyperspectral spectroradiometers using both airborne and ground platforms. Speci c re ectance curves, collected with the spectroradiometers, can be cor- related with nematode numbers and used to generate ne- matode contour maps for global positioning system (GPS) directed variable rate technology(VRT) nematicide appli- cations. Hyperspectral data may provide useful remote- sensing tools reducing the time consuming and costly grid sampling process required in precision nematicide appli- cations. 017 Economies in nematode management from precision agriculture – limitations and possibilities Ken E VANS ¤ and Andy B ARKER Nematode Interactions Unit, IACR-Rothamsted, Harpenden, Herts, AL5 2JQ, UK ¤ ken.evans@bbsrc.ac.uk The potato cyst nematodes (PCN), Globodera pallida and G. rostochiensis , represent a severe constraint to potato production in the United Kingdom. Management of PCN depends heavily on nematicides, which are costly. Of all the inputs in UK agriculture, nematicides offer the largest potential cost savings from spatially variable application, and these savings would be accompanied by environmental bene ts. The potential bene t:cost ratios for such a strategy will be considered, along with some of the risks. Maps of real PCN infestations in potato elds in which susceptible potato crops were grown will be used to demonstrate some of the principles and risks. The inverse relationship between population density before planting and multiplication rate of PCN makes it dif cult to devise reliable spatial nematicide application procedures, especially when the pre-planting population density is just less than the detection threshold. Also, the spatial dependence found suggests that the use of sampling grids that are too coarse is likely to produce misleading distribution maps. Coarse grids can miss patches of PCN, but an economic analysis of the risks of missing patches can be made. 018 Management strategies for nematode control in Europe Nicola G RECO 1 ; ¤ and Daniel E SMENJAUD 2 1 CNR, Istituto per la Protezione delle Piante, Sezione di Bari, Via G. Amendola 165/A, 70126 Bari, Italy 2 INRA, Unité ‘Interactions Plants-Micro-organismes et Santé Végétale’, B.P. 2078, 06 606 Antibes cedex, France ¤ nemang02@area.ba.cnr.it The improvement of food and environment quality is a priority of the European Union. Therefore, funds for agricultural research and management aim at achieving this goal and alternative strategies to chemicals are promoted. In Europe, the most severe nematode pests are cyst, root-lesion, root-knot (RKN), stem and bulb, citrus and virus vector nematodes. Classical control of eld crop nematodes relies on crop sequences, resistant cultivars when available and clean planting materials. Nematicides are used to control nematodes of high- value crops (vegetables, owers, nurseries) for which the ban of e.g. , methyl bromide is a concern. Soil solarisation, new resistant cultivars or rootstocks and soil- less crops are gaining interest as alternative methods. In perennials, management strategies may be preventive by using nematode-free plant material obtained through certi cation schemes or curative with tolerant rootstocks. Pre-plant soil fumigation is limited to severe nematode attacks. Research for genetic solutions is in progress for various crops, such as for RKN in Prunus spp. and Xiphinema index /GFLV in grape. For this latter problem, an original alternative to nematicides is the application of 128 Nematology</p>
<p>Symposium abstracts systemic herbicides to kill roots before pulling out the crop combined with fallow to eliminate the virus from surviving nematodes. 019 Nematode management practices in African agriculture E.E.A. O YEDUNMADE Department of Crop Production, University of Ilorin, Ilorin, Nigeria ceetie2@infoweb.abs.net The African continent is mostly exposed to tropical climates, which favour the reproduction and feeding activity of plant-parasitic nematodes all the year round. In various parts of Africa, many nematodes are parasitic on economic and food crops, but the three most important plant-parasitic nematodes are the root-knot nematodes ( Meloidogyne spp.), the root lesion nematodes ( Pratylenchus spp.) and the cyst nematodes ( Heterodera spp.) which attack and cause severe yield reductions in crops such as cowpea, soybean, maize, yam, cotton, coffee, sugarcane and several vegetables. Agriculture in Africa is characterised by small sized farms and low-level technology. As a result of these, the most commonly adopted nematode management practices in several parts of Africa are cultural control measures which are not capital intensive and which require little or no technical know-how on the part of the mostly illiterate peasant farmers. To a large extent, the use of synthetic nematicides is restricted to large and experimental farms, but the recent awareness of environmental safety coupled with the prohibitive costs of synthetic pesticides has encouraged research into safer and cheaper alternatives. The most commonly used cultural methods of nematode management in Africa are: i ) shifting cultivation and bush fallowing (until very recently due to land limitation, this method has played a very signi cant role in the control of many economically important plant parasitic nematodes); ii ) mixed cropping; iii ) use of soil amendments; iv ) soil tillage; v ) use of resistant varieties and healthy propagation materials; vi ) crop rotation; vii ) roguing and farm sanitation; and viii ) soil solarisation. 020 Nematode management in Russia and neighbouring countries of the former USSR E.M. M ATVEEVA Institute of Biology, Karelian Research Centre RAS, Pushkinskaya st, 11, Petrozavodsk, 185610, Karelia, Russia matveeva@bio.krc.karelia.ru In Russia and neighbouringcountries, of ten important ge- nera of plant parasitic nematodes, six have a great eco- nomic impact. They are Heterodera, Globodera, Meloi- dogyne, Ditylenchus, Pratylenchus and Helicotylenchus. The division of USSR into many independent states and recent economic reforms in Russia led to deep changes in agricultural practices. These changes increase dam- age of main crops caused by plant-parasitic nematodes, and provide the opportunity for some dangerous nema- todes to come back and new species to appear and spread. These countries are characterised by zones specialising in monocrop growing ( e.g. , cereals, potato, sugar beet, grapevine and cotton-sowing areas). Hence a close rela- tionship exists between the degree of crop concentration in high-specialistcollective farms and the acuteness of ne- matode problems. Damage caused by nematodes is one of the limiting factors in crop production. Annually farmers lose a signi cant part of crop yields due to poor control of the seed materials, low agricultural technologies and ab- sence of nematicides. Traditional nematode management includes the following measures: prophylactic(prevention of the nematode establishment in agricultural elds due to quarantine regulations and cleaning of propagation ma- terials), physical (control by heating and vapour), chem- ical (nematicides), crop rotations, resistant cultivars and some cultural practices (soil amendments). At present, al- ternative nematode control strategies are being developed. They are based on the use of biological products, wastes from logging and the timber industry, new resistant culti- vars with complex resistance to plant pathogens,and stim- ulation and modulation of host resistance by using of phy- tohormonal and adaptogenic phytoregulators and phyto- control technologies. 021 Nematode management strategies in East Asian countries Zen-ichi S ANO National Agricultural Research Center for Kyushu Okinawa Region, Nishigoshi, Kumamoto 861-1192, Japan East Asian countries have diverse agricultural systems. However, root-knot nematodes, cyst nematodes and root- lesion nematodes are important pests throughout this area. Extremely intensive farming systems are prevalent in Japan. Many farmers continuously cultivate high Vol. 4(2), 2002 129</p>
<p>Precision agriculture and GPS (14-17) and Global comparative nematode management (18-26) value crops such as tomato or melon for years in the same plastic greenhouses. Currently similar farming practices are increasing in Korea and other countries. In such intensive farming, control of soil-borne pests is inevitable to maintain pro table yields. Fumigation with nematicides is the most reliable and practical control measure. 1,3-dichloropropene is often applied with granular nematicides. Methyl bromide or chloropicrin is applied in elds where both nematodes and soil-borne diseases occur. The prohibition of methyl bromide is a serious problem for pest control. Solarisation of sealed plastic greenhousesfor about 30 days in mid-summer is an effective method with few adverse environmental effects. Cover crops such as Crotalaria spp. are also used to reduce nematode populationsand improve soil conditions. Tomato cultivars with resistance to root-knot nematodes are commercially available. However, resistant breaking races are present in many elds in Japan. 022 Management practices in South Asian agriculture Hari S. G AUR Division of Nematology, Indian Agricultural Research Institute, New Delhi-110 012, India hsg_nema@iari.ernet.in Southern Asia comprises very diverse and intensively cul- tivated areas, characterised by small farm holdings and economically poor, and often illiterate or poorly edu- cated, farmers. The nematode management practised over large areas, often inadvertently, depends upon crop ro- tation, tillage, solar heat and organic amendments. Use of nematicidal pesticides is very limited. Some organo- phosphates and carbamates are applied for the control of insect pests and rarely against nematodes. Small doses of pesticides are advised for application to nursery-beds or to seed of direct seeded crops. Research efforts have been made for nding sources of nematode resistance in crops and a few fairly resistant varieties or crops like rice, tomato, chillies, cowpea, mungbean, cotton, grapes, etc ., have been selected or speci cally bred. Use of ge- netic engineering for nematode resistant crops is being attempted. Biological control agents including imported and indigenous strains of Paecilomyces lilacinus , Tricho- derma viride , T. harzianum , Aspergillus niger and VAM, Glomus spp., Pasteuria penetrans , Pseudomonas uo- rescens , Bacillus subtilis etc ., have been found effective but their production and use are still very limited. Combi- nations of more than one practice have been designed for certain cropping systems to provide integrated nematode management modules to t into plant protection packages. 023 Nematode management strategies in major crops in the Australasian region Mike H ODDA CSIRO Entomology, GPO Box 1700, Canberra ACT 2601, Australia mike.hodda@csiro.au The Australasian region encompasses a huge range of agricultural systems, from subsistence to highly mechanised commercial farms. There are many different nematode pests and management strategies, but similar approaches in broad agricultural systems. Heterodera has been the major pests of broadacre low intensity farming of grains in the region, but its successful management by crop rotation and resistance have seen Pratylenchus emerging as major pests of this cropping system. In pasture, nematode management is directed largely towards resistance, with lesser efforts in agronomic practices and a range of emerging techniques including mulching and soil amendments. In intensive horticulture, Meloidogyne , Radopholus , Heterodera and, in New Zealand, Globodera are managed by phytosanitary controls, chemical methods, and emerging techniques. In woody crops, Meloidogyne , Tylenchulus , Xiphinema and criconematids are all important, and controlled mostly chemically. In small-scale horticulture Meloidogyne , Radopholus and Pratylenchus are most important, and controlled by enforced crop rotations. Quarantine and phytosanitation are also common themes in nematode management because a number of pest species common in the rest of the world are absent from countries or certain areas. Trends are for increasing use of plant resistance, but allied with emerging techniques and greater knowledge of the pest species systematics and biology. 024 Nematode management in North American crops D.P. S CHMITT ¤ and B.S. S IPES University of Hawaii, Plant and Environmental Protection Sciences, 3190 Maile Way, Honolulu, HI 96822, USA ¤ Schmitt@hawaii.edu The crop and the associated nematodes in North America in uence the type of management used. Control of nematodes in low cash value crops depends heavily on 130 Nematology</p>
<p>Symposium abstracts host plant resistance and crop rotation. For example, the soybean cyst nematode is largely controlled with a combination of crop rotation, often the non-host corn, and nematode race speci c cultivars. In contrast, elds designated for planting with high cash value crops are frequently fumigated or treated with a nonfumigant nematicide. Treatment with dichloropropeneis a common practice for many vegetable crops and fruit crops. Methyl bromide fumigation is used on crops such as strawberry because bene ts beyond nematode control, such as control of numerous other pathogens and weeds, are achieved with a single treatment. For nematode management in some perennial tree crops, resistant rootstocks are employed. A case in point is the grafting of peach scions onto ‘Nemaguard’ rootstocks for areas where root-knot nematode is a problem. Sanitation is a crucial management component for potato production in the Paci c Northwest in the USA. Cash value of the crop and the longevity of the crop are major factors in the selection of management tactics. 025 Nematode management practices in MesoAmerica Nahum M ARBAN -M ENDOZA Dpto de Parasitología Agrícola, Universidad Autónoma Chapingo, Chapingo, México The crops of greatest socioeconomic importance in MesoAmerica (southern Mexico and Central America) are coffee, banana, cucurbits and tomato. Various phytoparasitic nematodes are associated with them but without doubt the gall inducers ( Meloidogyne spp. and Nacobbus aberrans ), along with nematodes causing root lesions ( Pratylenchus spp. and Radopholus similis ), are widely considered by producers to be factors limiting productivity. In this talk, we will discuss efforts that are being made to attack nematode problems by crop and by geographic zone. We will try to distinguish that which is academic from that which has been adopted by producers. In this process, we will try to put into perspective the dif culties of making integrated nematode management (INM) a reality in the eld. Based on reports in the literature the following generalisations can be made: i ) there are few studies; ii ) most deal with chemical control; iii ) non-chemical alternatives for the most part are based on excellent investigations but have not been adopted by producers; and iv ) there are very few demonstration studies on non-chemical alternatives at the commercial farm level. The distinct socioeconomic world of MesoAmerican producers is a goal for future generationsof nematologistsand through INM techniques they should develop different INM systems appropriate to the needs and socioeconomic realities of producers. 026 The Mediterranean agrosystem as an agroecologicalmodel J. Antonio L ÓPEZ -P ÉREZ 1 ; ¤ , Antonio B ELLO 1 , Javier T ELLO 2 , Avelino G ARCÍA -Á LVAREZ 1 and Maria A RIAS 1 1 Dpto Agroecología, Centro de Ciencias Medioambientales, CSIC, Serrano 115 dpdo, 28006 Madrid, Spain 2 Dpto Producción Vegetal, Escuela Politécnica Superior, CITEB II, Univ. Almería, Cañada de S. Urbano s/n, 04120 Almería, Spain ¤ pezperez@hotmail.com The necessity of designing a new agricultural model is proposed, which would take into account the demands of consumers, who are concerned not only about greater food safety, but also about the environmental and social impact of agricultural production. New models of agriculture are emerging, which use the ecological management of agricultural systems as a reference, based on the management of biological, environmental and cultural diversity among territories. Environmental and social aspects of Mediterranean agriculture are analysed as a diversi ed agroecological model, which could serve as a reference for the development of new productive systems, integrating proposals from the European Community agricultural policy. It is also indicated that the environmental characteristics of the Mediterranean environment permit the design of an integrated production system based fundamentally on the use of non-chemical alternatives for nematode control, which prevent pests and disease from becoming serious problems. The de nition of ‘Mediterranean’ refers to a concept that describes a region with its own identity, emerging with characteristics from a speci c climate and environment and high agroecological values produced when various cultures interacted and the outcome of integration by the people of the Mediterranean basin. Moreover, the contributions must be emphasised of the great biotechnological revolution and the impact of the discovery of America on diversi cation in the production of high quality agricultural systems. Vol. 4(2), 2002 131</p>
<p>Marine and fresh water nematodes (27-30) 027 Re ections on the systematics of the Dorylaimoidea, a group of terrestrial and freshwater nematodes P.A.A. L OOF Department of Nematology, Wageningen University, P.O. Box 8123, 6700 ES Wageningen, The Netherlands Piet Loof@nema.dpw.wau.nl The system of Dorylaimoidea is (some well-de ned families excepted) unsatisfactory.It is dif cult to establish groups on the basis of synapomorphies,the morphological characters being distributed erratically, many species were discovered and described in the 19th century when knowledge of the morphology was almost nil (it remained in this state until 1936); moreover the importance of tail shape (very easy to observe) has been overrated strongly. Furthermore, the literature is full of misidenti cations and should be consulted very critically. The author gives some suggestions that in future might lead to development of a better system. 028 Maintenance of biodiversity through predation and competition in freshwater nematodes? Iris V ORNDRAN ¤ and Walter T RAUNSPURGER Dept of Animal Ecology, University Bielefeld, Morgenbreede 45, 33615 Bielefeld, Germany ¤ iris.vorndran@biologie.uni-bielefeld.de Why does a particular habitat harbour a certain number of species and how is this species diversity maintained? Theory predicts that biotic interactions may give rise to an arms race that favours variability. Nematodes are ideal to study ® -diversity. They show high abundance and species richness and play a central role in soil food webs. Species within a genus ( e.g ., Eumonhystera ) show differences in the width of their buccal openings, which could be interpreted as mutual exclusion through competition. In this study we review the species richness of freshwater nematodes and ask whether predators and competitors can explain species richness in the eld. The number of freshwater nematode species in 28 different lakes ranges between three and 120. Within 1 year, ® - diversity remains at a constant level within a habitat in Lake Brunnsee and Königssee. To study the effect of predators we started mesocosm experiments with different macrobenthic taxa and analysed soil samples of 12 alpine lakes. Plathelminthes, chironomidsand annelids do not in uence nematode abundance. The in uence on nematode diversity through macrobenthic predators, predacious nematodes and the diversity of trophic groups will be presented. We discuss the relevance of these results for the maintenance of biodiversity. 029 Status quo of limno-nematology: how close are we to understanding the ecology of nematodes in inland water bodies? Abebe E YUALEM Institute of Cell, Animal and Population Biology, Ashworth Laboratories, King’s Buildings, West Mains Rd, The University of Edinburgh, Edinburgh EH9 3JT, Scotland, UK Despite an early start, limno-nematology can safely be called a science in its infancy compared to marine nematology or other aspects of limno-benthology. Past limited interest in free-living limnetic nematodes has given way to an upsurge of interest in the past two decades. Most nematological research in limnetic habitats on free-living forms still has a lot to achieve compared to studies in the marine meiobenthos. Lotic free-living nematodes are relatively less well studied than those from lentic habitats. Taxonomic reports continue to appear, but a noticeable proportion of the recently published work was devoted to their ecology, i.e ., mainly to distribution, spatial and temporal variation, abundance, diversity, and the relation of these phenomena with some biotic and abiotic factors. Experimental data that revitalises our notion of their ecological role has started to appear. Their potential use as indicators of water pollution was also strengthened. Hitherto ignored tropical habitats were studied, albeit to a limited extent. Lentic nematodes seem not to conform to the general understanding of biodiversity gradient with latitude. Gaps are indicated and recommendations made. 030 Molecular studies of nematode diversity: past, present and future Alex R OGERS 1 and P. John D. L AMBSHEAD 2 1 British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 0ET, UK 2 The Natural History Museum, London SW7 5BD, UK Marine nematodes are an important component of the ecosystem and their ecological and biodiversityproperties make them a potentially ideal taxocene for testing ecological theory and biomonitoring.Work at the species level will yield signi cantly greater information than 132 Nematology</p>
<p>Symposium abstracts work at higher taxonomic levels. However, identifying samples of nematodes is dif cult, time consuming and expensive. In addition, the morphological species concept used for classi cation may be unreliable, and known species, especially those used for biomonitoring, may be complexes of siblings with different functional responses, especially when animals are examined across wide geographic ranges. Molecular methods offer a more objective estimation of species identity. These techniques range from sequencing informative segments of DNA and using them to de ne ‘molecular operational taxonomic units’ (M-OTU) to assessment of species diversity in samples through techniques such as denaturing gradient gel electrophoresis (DGGE). Identi cation of species in bulk samples offers a rapid and comparative means to analyse samples from different sites, even over large geographic ranges. In the future, genomic technologies may offer the prospect of developing ‘identi cation chips’ or means of identifying speci c gene expression patterns associated with activities of nematodes related to environmental monitoring. 031 Comparative nematode genomics Mark B LAXTER 1 , John P ARKINSON 1 , Jen D AUB 1 , Claire W HITTON 1 , Marian T HOMSON 1 , David G UILIANO 1 , Neil H ALL 2 , Mike Q UAIL 2 and Bart B ARRELL 2 1 Institute of Cell, Animal and Population Biology, University of Edinburgh, Ashworth Laboratories, Kings Buildings, Edinburgh EH9 3JT UK 2 The Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK The completion of the sequencing of the Caenorhabditis elegans genome in 1998 was a milestone in biology. The genome sequence has spurred discoveries in basic biomedical science, but is of added importance to us as nematologists because, of course, C. elegans is a nematode. We, and others, are engaged in large scale projects which aim to gather genomics data from a phylogenetically and biologically diverse selection of nematodes. Due to funding constraints, most of this effort is focussed on parasites of humans and our domestic animals. This presentation highlights ndings from these ongoing nematode genome projects, illustrating topics such as the conservation of synteny and linkage between C. elegans and other nematodes, the nematode-speci c and parasite-speci c genes we have identi ed, and the prospects for using comparative genomics to identify new control methods. Our data and analyses are available at http://www.nematodes.org . 032 On the evolution of parasitism genes Geert S MANT Laboratory for Nematology, Wageningen University, Binnenhaven 5, Wageningen, The Netherlands geert.smant@nema.dpw.wau.nl In the last 5 years considerable effort has been put into the identi cation of parasitism genes from sedentary plant-parasitic nematodes. Thousands of (partial) DNA sequences are now available from several nematode species, which allows comparison of gene expression in plant-parasitic and other nematode species. From this comparison it is evident that plant-parasitic nematodes have evolved a set of genes that have no homologues in other nematodes or even in other phyla. Similarly, plant-parasitic nematodes have genes in common with other plant-pathogens, which are absent in other groups of nematodes. And nally, plant-parasites and animal parasites share a unique set of homologues, too. Pieces of this evolutionary puzzle will be illustrated with examples. 033 Parasitism gene discovery in sedentary phytonematodes Thomas J. B AUM Department of Plant Pathology, Iowa State University, Ames, IA 50011, USA tbaum@iastate.edu Parasitism genes expressed in phytonematode pharyngeal gland cells code for the stylet secretions that control the process of plant parasitism. In sedentary endoparasitic nematodes, the products of parasitism genes induce the elaborate modi cations of plant cells into feeding cells required to support growth and development of the nematode. Efforts to identify and characterise parasitism genes have been accelerated by several molecular approaches, including direct analyses of secreted proteins and cloning of genes differentially expressed in the pharyngeal gland cells. For differential gene expression, comparative analyses have been conducted among nematode life stages and among nematode tissues. The most direct approach for cloning parasitism genes, however, involves the microaspiration of pharyngeal gland cell cytoplasm from multiple parasitic stages for cDNA library construction followed by expressed Vol. 4(2), 2002 133</p>
<p>Parasitism in Nematoda (31-34) and Current trends and future directions in entomopathogenic nematode research (35-38) sequence tag sequencing and bioinformatic analyses. Current results reveal a large number of novel parasitism genes and paint a complex picture of cellular events under speci c control by the nematode. Furthermore, only very few parasitism genes have homologues in Caenorhabditis elegans , limiting the usefulness of this model nematode in studying nematode adaptations for plant parasitism. 034 Adaptations of parasitic nematodes to mammalian host immunity Murray E. S ELKIRK ¤ and Kleoniki G OUNARI S Department of Biological Sciences, Biochemistry Building, Imperial College of Science, Technology & Medicine, London SW7 2AY, UK ¤ m.selkirk@ic.ac..uk Nematode parasites of man and animals are typi ed by their longevity in the mammalian host, although little is known about molecular mechanisms of establishment and survival of these organisms in the face of aggressive immune responses. In addition to a robust arsenal of anti-oxidants, there is growing evidence that parasite- secreted products include a panel of anti-in ammatory agents which act in concert to suppress the recruitment and activation of effector leukocytes. These products may constitute enzymes which hydrolyse pro-in ammatory signalling molecules such as chemokines, lipid mediators, and nucleotides released from damaged tissues, or proteins which antagonise receptors involved in this process. In addition, a number of cytokine homologues are expressed which have the potential to modulate immune responses. Recent EST projects have highlighted abundantly expressed genes which encode secreted proteins of unknown function,although the lack of genetic knockout techniques has resulted in a bottleneck in the assessment of these proteins as potential mediators of persistence and the mechanisms involved. RNA interference (RNAi) offers an opportunityto address some of these problems, and we are applying this technique to address this speci c question. Progress and current data in this area will be reviewed in this presentation. 035 Biosystematics of entomopathogenic nematodes: current status and future directions Alex P. R EID 1 ; ¤ and S. Patricia S TOCK 2 1 CABI Bioscience (UK Centre), Bakeham Lane, Egham, Surrey TW20 9TY, UK 2 Dept of Plant Pathology, University of Arizona, Tucson, AZ 85721-0036, USA ¤ a.reid@cabi.org Assimilation of molecular approaches into nematode systematics has escalated dramatically in the last few years. With respect to entomopathogenic nematodes (EPN), various molecular techniques have been used for diagnostic purposes and for separating cryptic species, populations and strains. Another valuable contribution to EPN systematics has been the discovery and description of new species in a phylogenetic context. This new approach has been applied in taxonomic decisions, including re-evaluation of previously described species and their relationships.In this presentation we will discuss the importance of several molecular markers and their current use for diagnosis and identi cation of EPN at different taxonomic levels. Additionally, we will discuss the application of combined evidence datasets ( i.e. , morphological C molecular) to interpret phylogenetic relationships among EPN species and as tools to make predictions of ecological traits that will have signi cance for the application of EPN in biocontrol programs. 036 Advances in molecular biology of entomopathogenic nematodes Itamar G LAZER Department of Nematology, ARO, The Volcani Center, Bet Dagan, 50250 Israel glazeri@netvision.net.il Entomopathogenic steinernematid and heterorhabditid nematodes have been used for almost a decade as biological control agents of insect pests. Despite the impressive progress in propagation and application little has been done, so far, to utilise the advances in molecular biology techniques to advance the use of these nematodes. Molecular tools have been use mainly for identi cation and classi cation of entomopathogenic nematodes. In recent years, molecular approaches have been employed to study key processes in development and survival of steinernematids and heterorhabditids. These included: i ) isolation and characterisation of genes involved in the initiation of developmentfrom the infective juvenile stage and ii ) using cDNA subtractive hybridisation to identify genes that are differentially expressed during exposure to desiccation stress. The advances in the molecular research are reviewed. 134 Nematology</p>
<p>Symposium abstracts 037 EPN product development: from strain discovery to commercial eld application Ralf-Udo E HLERS Institute for Phytopathology, University of Kiel, Dept of Biotechnology and Biological Control, Klausdorfer Str. 28-36, 24223 Raisdorf, Germany ehlers@biotec.uni-kiel.de Entomopathogenic nematodes (EPN) have an enormous potential to serve as biocontrol products in protected and outdoor crops. There are several examples of the successful introduction of EPN products into the ornamental and turf care market. However, promising EPN strains often sit on the shelf of highly motivated scientists and cannot easily be transferred to product development. After the control potential of a strain has been demonstrated under eld conditions, research into biotechnology has to solve the problem of mass production, down- and upstream processing, storage and formulation. Quality control procedures are needed to predict eld performance of production batches. Some countries require registration for EPN causing signi cant costs and delays in product introduction. Prior to this development, information is needed on alternative control strategies, the commercial signi cance of the target pest and an approximate cost-bene t analysis for the use of EPN. Marketing needs to motivate potential users to try alternative, environmentally friendly control strategies. Product introduction is accompanied by intensive trials under different production and environmental conditions in order to investigate the ecological potential and limits of the EPN strain. 038 Investigating mutualism between entomopathogenic bacteria and nematodes Eric M ARTENS ¤ , Eugenio V IVAS , Kurt H EUNGENS † , Charles C OWLES and Heidi G OODRI CH -B LAIR Dept of Bacteriology University of Wisconsin-Madison, 1550 Linden Drive, Madison, WI 53706, USA † Present address: CLO-Gent-DGB, Burg. Van Gansberghelaan 96, B-9860 Merelbeke, Belgium ¤ ecmartens@students.wisc.edu The entomopathogenic nematode Steinernema carpocap- sae forms a mutualistic association with the bacterium Xenorhabdus nematophila . At least one nematode devel- opmental stage, the infective juvenile (IJ), is colonised at a discrete intestinal location by multiple bacteria and is re- sponsible for transporting bacteria between insect hosts. We are using microscopic and molecular biological tech- niques to investigate the cellular and molecular interac- tions between nematode and bacteria with the follow- ing goals: i ) developing a detailed model of nematode- bacteria interactions throughoutthe course of their associ- ation and ii ) de ning bacterial factors that are important to this mutualism. Achieving these goals will yield general insight into mechanisms of microbe-host associations, as well as provide information important to the further devel- opment of these organisms as biocontrolagents. Construc- tion of a GFP-labeled X. nematophila strain has allowed direct observation of bacteria-nematode associations, re- sulting in the description of distinct stages of the mutual- istic interaction. Additionally,bacterial mutants have been generated that are either completely or partially defective in the ability to colonise nematodes. We are now char- acterising the genetic lesions in these mutants to identify genes and their products that are necessary for colonisa- tion. 039 Nematode management in subsistence farming in Africa with emphasis on bananas, plantains and yam cropping systems Roger F OGAIN 1 ; ¤ , Charles K WOSEH 2 and Mieke D ANEEL 3 1 CARBAP (Centre Africain de Recherche sur bananiers et Plantains) BP 832, Douala, Cameroon 2 Department of Crop Science & Technology, Kumasi, Ghana 3 ITSC, Private Bag X11208, Nelspruit 1200, South Africa ¤ rfogain7@yahoo.fr Bananas ( Musa AAA), plantains ( Musa AAB) and food yams of the genus Dioscorea play a major role in the diet of many people in Africa. These crops are also an important source of revenues to farmers in rural areas. World production is estimated at about 86 m t for bananas and plantains and about 34.5 m t for food yams. Nematodes are among the major biotic constraints to these crops in Africa, causing signi cant yield losses. The major species attacking bananas and plantains in Africa are Radopholus similis and Pratylenchus spp. ( P. goodeyi and P. coffeae ). Scutellonema bradys, P. coffeae and nematodes of the genus Meloidogyne are the damaging species on yams. This report presents progress on the management of these pests on banana, plantain and yams in subsistence farming systems where these crops are often grown in association with tree crops such as coffee and cocoa and other food crops, including cassava cocoyams and maize. Vol. 4(2), 2002 135</p>
<p>Nematode management in subsistence farming (39-42) 040 Nematode management in subsistence farming in Mexico Rosa H. M ANZANILLA -L ÓPEZ Nematode Interactions Unit, Harpenden, Herts. AL5 2JQ, UK rosa.manzanilla-lopez@bbsrc.ac.uk Factors such as geography, climate, vegetation, biogeog- raphy and human settlement have contributed in de n- ing Mexican rural and socio-economic scenarios. Mexi- can agriculture has two main approaches: the campesino and the agro-industrial, both with contrasting character- istics related to production and management strategies against pests and diseases. In campesino and subsistence systems, low external-inputstrategies that have proved ef- fective in the management of the most common and im- portant plant-pathogenic species of nematodes in Mexico ( i.e ., Meloidogyne spp., Nacobbus aberrans , Pratylenchus spp. and Punctodera chalcoensis ), include production of plant and tree seedlings free of nematodes, physical con- trol methods, rotations, organic amendments, antagonistic plants, suppressive soils and maintenance of biodiversity. Most of these practices are considered to be environmen- tally friendly and, although subsistence agriculture can produce enough food to feed families or small communi- ties, it may be adversely affected by socio-economic fac- tors such as availability of good land, adequate water, mi- gration, pressures on land use, shortened rotations, crop value and changes in cultural patterns, thus compromis- ing sustainability. 041 Nematode management in subsistence farming in the Caribbean E. F ERNÁNDEZ 1 ; ¤ , P. Q UÉNÉHERVÉ 2 and P. DE LA C RUZ 3 1 Instituto de Investigaciones de Sanidad Vegetal, Calle 110 #514, Miramar, Habana, Cuba 2 IRD, BP8006, 97259, Fort-de-France Cedex, Martinique 3 Instituto Dominicano de Investigaciones Agropecuarias y Forestales IDIAF, Dominican Republic ¤ efernandez@insav.cu The key characteristics of Caribbean islands are insularity and diversity: diversity in size, climate, vegetation, crops, economy and human history. Subsistence farming also re ects the diversity from island to island. It is possible to look at these differences in considering some important subsistence crops and related nematode problems e.g ., small grain cereals, roots and tubers, banana and plantains, fruits and vegetables. From a strict nematological viewpoint, all these crops can suffer severely from nematode damage e.g ., Ditylenchus dipsaci, Meloidogyne spp., Pratylenchus spp ., Radopholussimilis, Scutellonema bradys but often the expertise of farmers, the extensive way the lands are cultivated, and the mixed-crop production systems let these crops escape nematode damage. Numerous nematological studies have been conducted in the Caribbean with different levels of knowledge, technical skill and success in order to improve nematode management on subsistence crops through fallow and crop rotation, organic soil amendment, use of resistant cultivars, non-host and antagonistic plants. The experience of Cuba, Dominican Republic, Guadeloupe, Jamaica and Martinique would be a good example of what can be achieved with low inputs within the scope of sustainable agriculture. 042 Nematode management in subsistence farming in Bangladesh, Nepal and Pakistan Anjum M UNIR 1 , Ramesh Raj P OKHAREL 2 and John B RIDGE 3 ; ¤ 1 Crop Diseases Research Institute, NARC, Park Road, Islamabad-45500, Pakistan 2 Institute of Agriculture and Animal Science, Rampur, Chitwan, Nepal 3 CABI Bioscience, UK Centre, Bakeham Lane, Egham, TW20 9TY, UK ¤ j.bridge@cabi.org The economy of Bangladesh, Nepal and Pakistan is agriculturally based. The main crops of the region are wheat, rice, sugarcane, cotton, maize, fruit orchards and vegetables. In Bangladesh, Ditylenchus angustus, Meloidogyne graminicola , and Hirschmanniella oryzae are all major pests of rice. Management of ufra is by the burning of stubble. Root-knot can be prevented on rice by the transplanting of healthy seedlings and suitable rotations. No methods to successfully manage Hirschmanniella are known. The important nematodes of vegetables are root-knot species. In Nepal, M. graminicola, H. oryzae and H. mucronata are associated with rice when followed by wheat, winter legumes, corn and summer legumes. In upland systems, where corn, wheat, different legumes and vegetables are grown, different nematode species are reported. Meloidogyne is reported from almost vegetables, legumes, fruit, ornamentals and weeds. M. aranaria, M. incognita and M. javanica are limited to Terai (plains) and M. 136 Nematology</p>
<p>Symposium abstracts hapla to the hills. Tylenchulus semipenetrans is found associated with citrus crops causing slow decline. Soil solarisation and long-term use of farmyard manure show encouraging results, while compost prepared from manures of different animal species, host resistance and chemicals in bringal, tomato, gram and pigeon pea are used to control Meloidogyne species . In Pakistan, root- knot is the major problem. Root-knot nematodes are damaging vegetables and M. graminicola is associated with rice and wheat. Potato cyst nematode ( Globodera rostochiensis ) is restricted to northern Pakistan. Some success in the management of this nematode is achieved by growing turnips, carrots and peas before potato crop, thereby lowering the nematodes population almost 70%. Trap cropping is tested and tobacco is reported to induce signi cant amount of hatch. Other important nematodes are R. similis in banana and T. semipenetrans in citrus. In vegetables root-knot is one of the major problem in almost all the vegetable growing areas of Pakistan, M. incognita, M. javanica, M. arenaria are found in the plains whereas M. hapla is found in the hills. Most farmers have small land holdings and cannot afford chemical controls. Paecilomyces lilacinus, Pasteuria penetrans, and Verticillium sp. are being tested, as well as neem products for the management of plant- parasitic nematodes, particularly root-knot nematode. 043 Shared signal transduction pathways lead to nematode parasitism, rhizobial symbiosis and programmed plant development Hinanit K OLTAI 1 ; ¤ , Jennifer S CHAFF 2 and David B IRD 2 1 Department of Genomics, A.R.O. Volcani Center, Bet Dagan 50250, Israel 2 Department of Plant Pathology, North Carolina State University, Raleigh 27695, NC, USA ¤ hkoltai@agri.gov.il During the compatible parasitic interaction, root-knot nematodes ( Meloidogyneincognita ) face many challenges to successfully infect their host, including avoiding host defences, and redirecting host gene expression to establish the complex structures of giant cells, central to the parasitic relationship.Conceivably,rhizobial bacteria ( Sinorhizobium meliloti ) symbionts face similar challenges during establishment of nitrogen xing nodules. Our ndings of similar pattern of gene expression in giant cells and nodules of two transcription regulators required for the establishment of shoot and root meristems (PHAN and KNOX) of ccs52 , which encodes a mitotic inhibitor responsible for nuclear endoreduplication, and ENOD40 , which encodes an early, nodulationmitogen, suggest a model in which inputs from nematodes and rhizobia elicit a developmental pathway. This developmental pathway converges at PHAN and KNOX to modulate phytohormones, and subsequently diverges to form giant cells, nodules and meristems. Gene ablation experiments in tomato further showed that PHAN is necessary for giant cell formation, and is epistatic to KNOX . Our recent nding of a strong homologue of S. meliloti nodL in root-knot nematode suggests similarities between the endosymbiontsthemselves, and an intriguing possibility is that nematode and rhizobia produce similar signalling molecules to suppress host defence responses and/or to induce novel plant structures. 044 Syncytium development: the result of a sophisticated manipulation of plant cells by cyst nematodes Aska G OVERSE 1 ; ¤ , Aneta K ARCZMAREK 1 , Magdalena P IERZGALSKA 2 , Hein O VERMARS 1 , Marcin F ILIPECKI 2 , Jaap B AKKER 1 and Johannes H ELDER 1 1 Laboratory of Nematology, Department of Plant Science, Wageningen University, Binnenhaven 5, 6709 PD Wageningen, The Netherlands 2 Department of Plant Genetic Breeding and Biotechnology, Warsaw Agricultural University, Nowoursynowska 166, PL-02-787 Warsaw, Poland ¤ Aska.Goverse@nema.dpw.wau.nl Potato cyst nematodes have evolved a sophisticated way to parasitise their host plants. They migrate intracellularly through the root, and an outer cortex cell is selected as a starting point for syncytium formation. The recruitment of plant cell wall-degrading enzymes by the nematode results in an expansion of the syncytium towards the vascular bundle via a so-called cortical bridge. A local accumulation of auxin is crucial for syncytium development. Analysis of cellulase expression patterns in tomato revealed that two auxin-inducible members ( LE- Cel7 and LE-Cel8 ) were speci cally up-regulated during the onset of syncytium development. Intriguingly, nodule formation in legumes starts in the cortex, proliferates towards the stele and is also accompanied by a local accumulation of auxin. This process is preceded by the expression of ENOD40 . To see whether this gene is also essential for syncytium development, the role of ENOD40 was investigated in the non-legumes tomato and Arabidopsis upon cyst nematode infection. To unravel the Vol. 4(2), 2002 137</p>
<p>Compatible parasitic interactions (43-46) and Resistance breeding against sedentary nematodes (47-52) molecular mechanisms that underlie syncytium induction more thoroughly, a high throughput approach is needed. cDNA-AFLP was used to monitor the expression of auxin-regulated genes in cyst nematode-infected tomato roots, and some preliminary results will be presented. 045 Cell cycle genes as markers to study the ontogeny of nematode feeding sites in plant roots Janice D E A LMEIDA -E NGLER 1 ; ¤ , Gilbert E NGLER 1 ; 2 and Godelieve G HEYSEN 1 ; 3 1 Departments of Molecular Genetics and Plant Genetics, Flanders Interuniversity Institute for Biotechnology (VIB), Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium 2 Laboratoire Associé de l’Institut National de la Recherche Agronomique (France), Ghent University, B-9000 Gent, Belgium 3 Vakgroep Moleculaire Biotechnologie, Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen, Universiteit Gent, Coupure links 653, B-9000 Gent, Belgium ¤ jaalm@gengenp.rug.ac.be Research on the ontogeny of feeding sites induced by sedentary plant endoparasitic nematodes has been in focus already for many decades. Nematodes induce root cells to de-differentiate into large multinucleated and cytoplasm-dense feeding cells. We have used Arabidopsis thaliana as a model host to study cell cycle progression in nematode feeding sites induced by the root-knot nematode Meloidogyne incognita and the cyst nematode Heterodera schachtii . Cell cycle markers were used to monitor how nematode feeding sites develop and what the initial signals are that trigger certain root cells to evolve into giant cells embedded in a gall, or into a syncytium. Tritiated thymidine incorporationexperiments were applied to monitor DNA synthesis, which was used as a marker for the S phase of the cell cycle. Extending our analysis, the expression pattern of two CDKs and two mitotic cyclins were examined. The cycB1;1 gene was used as a marker for the G2 phase, the cdc2bAt and cycA2;1 for the S and G2 phases whereas the cdc2a gene was used as a marker for all cell cycle phases. Nematode infected seedlings were also treated with two cell cycle inhibitors (hydroxy-urea and oryzalin) to investigate the relevance of DNA synthesis and mitosis on the development of these feeding sites. A strong correlation was observed between initiation of feeding cells by both root-knot and cyst nematodes and the induction of DNA synthesis and the expression of particular cell cycle genes. Our results show that endoreduplication and mitotic cycles play a role during the root cell de-differentiation process caused by nematode infection. 046 Characterisation of plant genes involved in giant cell formation induced by root-knot nematodes in Arabidopsis thaliana and Medicago truncatula Bruno F AVERY 1 ; ¤ , Fabien J AMMES 1 , Philippe L ECOMTE 1 , Arnaud C OMPLAINVILLE 2 , Jose Maria V INARDELL 2 , Danièle V AUBERT 2 , Peter M ERGAERT 2 , Adam K ONDOROSI 2 , Eva K ONDOROS I 2 , Martin C RESPI 2 and Pierre A BAD 1 1 Unité Interactions Plantes-Microorganismeset Santé Végétale, INRA, 123, Bld F. Meilland, BP 2078, 06606 Antibes Cedex, France 2 Institut des Sciences Végétales, CNRS, Avenue de la Terrasse, 91198 Gif sur Yvette, France ¤ favery@antibes.inra.fr To identify plant genes involved in giant cell formation induced by the root-knot nematode Meloidogyne inco- gnita , a promoter trapping strategy was developed in Ara- bidopsis thaliana . We identi ed a gene, NEC , early up- regulated in the giant cells. During root development, this gene is expressed in meristems including initiation sites of lateral roots. This gene encodes a calcium-binding pro- tein with an EF-hand motif. In order to investigate its function, analysis of homozygous nec plants and plants over-expressing sense or anti-sense gene were carried out. The role of NEC in signal transduction will be discussed. Secondly, we investigated whether nitrogen- xing nod- ules and giant cell formation induce distinct or overlap- ping regulatory pathways in Medicago truncatula . We studied expression patterns of nodule-expressed genes af- ter infection with M. incognita. Analyses of promoter- GUS fusions indicate an accumulation of the cell cycle gene CCS52a in giant cells while the early nodulin gene ENOD40 expression was detected only in cells surround- ing the giant cells. Interestingly,on transgenic plants over- expressing enod40 , a signi cantly higher number of galls was formed. In addition, results obtained on macroarray analysis will be discussed. Taken together, these results suggest that certain events might be common between gi- ant cell formation and nodule development. 047 Molecular markers for resistance to cyst nematodes in potato 138 Nematology</p>
<p>Symposium abstracts Erin B AKKER 1 ; ¤ , Jeroen R OUPPE VAN DER V OORT 1 , Herman VAN E CK 2 , Jaap B AKKER 1 and Aska G OVERSE 1 1 Laboratory of Nematology, Wageningen University, Binnenhaven 5, 6709 PD Wageningen, The Netherlands 2 Lab. Plant Breeding, Wageningen University, The Netherlands ¤ erin.bakker@nema.dpw.wau.nl A mapping strategy based on catalogued, chromosome- speci c AFLP markers facilitated the localisation of genes for resistance against potato cyst nematodes. The genes Gpa2 , Grp1 , Gpa3 , Gpa5 and Gpa6 could relatively easily be mapped with this AFLP catalogue. Fine mapping showed that most of these genes are located in genomic regions harbouring also resistance genes for other pathogens. Especially, Grp1 and Gpa5 on chromosome V and Gpa3 on chromosome 11 seem to be located in ‘hotspots’ for resistance. Remarkably, both qualitative and quantitative resistances map to these resistance gene clusters indicating that they might be controlled by similar molecular mechanisms. Dissecting resistance in potato will in the near future be accelerated by the availability of an ultra dense genetic map. Using an offspring of about 100 individuals,approximate 10 000 AFLP markers have been placed on the map of potato. The possibilities for marker-assisted breeding in potato will be discussed. 048 The identi cation and development of resistance to Meloidogyne arenaria in groundnut J.L. S TARR 1 ; ¤ , G. C HURCH 2 and C.E. S IMPSON 2 1 Department of Plant Pathology & Microbiology, Texas A&M University, College Station, TX 77843, USA 2 Texas Agricultural Experiment Station, Stephenville, TX 76401, USA ¤ starr@ppserver.tamu.edu Highly effective resistance to M. arenaria in groundnut was rst discovered in diploid wild Arachis spp. Development of a synthetic tetraploid interspeci c hybrid ( A. batizocoi £ ( A. diogoi £ A. cardenasii )) that was cross-compatible with cultivated groundnut was the rst step towards achieving a resistant cultivar. A backcross breeding programme was used to introgress the resistance into agronomically acceptable groundnut genotypes. The rst cultivar (COAN) released from this breeding programme was selected from the fth backcross generation. Yields of COAN in elds infested with M. arenaria were 20-120% greater than those of susceptible cultivars, but in non-infested elds yield of COAN was only 80-90% of the susceptible cultivars. The cultivar NemaTAM was released from the seventh backcross generation and has yields equal to that of susceptible cultivars in non-infested elds. In elds infested with M. arenaria , yields of NemaTAM are greater than those of COAN. Resistance in COAN and NemaTAM is inherited as a single dominant gene. The resistance in the synthetic triple species hybrid is inherited as one dominant gene and one recessive gene. Thus, at least one additionalresistance gene appears to exist in a genotype cross-compatible with cultivated groundnut that can be used to increase the durability of resistance. 049 Global importance of cyst ( Heterodera spp.) and lesion nematodes ( Pratylenchus spp.) on cereals: a review of yield loss studies, populations dynamics and progress of the use of host resistance for nematode control using traditional methods with the application molecular tools Julie N ICOL 1 ; ¤ , Roger R IVOAL 2 , Sharyn T AYLOR 3 and Maria Z AHARIEVA 4 1 International Wheat and Maize Improvement Center (CIMMYT), Wheat Program, P.O. Box 39, Emek, 06511, Ankara, Turkey 2 UMR INRA/ENSAR, Biologie des Organismes et des Populations appliquée à la Protection des Plantes (BiO3P), BP 35327, 35653 Le Rheu, France 3 South Australian Research and Development Institute (SARDI), Field Crops Pathology Unit, GPO Box 397 Adelaide, SA 5001, Australia 4 CIMMYT, Wheat Program, A.P. 6-641, 06600 Mexico D.F., Mexico ¤ jnicol@cgiar.org The sedentary cereal cyst nematode (CCN, Heterodera spp.) and the migratory endoparasitic root lesion nema- tode (RLN, Pratylenchus spp.) have a global distribution and are economically important to cereal production sys- tems worldwide. Several species of CCN and RLN cause yield loss on cereals; however, morphologically these ge- nera are dif cult to identify at the species level. The po- pulation dynamics and plant damage thresholds in rela- tion to yield loss will be discussed and compared for both types of nematodes. Resistance is one of the major con- trol measures and offers the possibility to reduce popula- tions of nematodes below damaging thresholds. Through extensive screening work, several sources of plant resis- tance at various levels have now been identi ed for both Vol. 4(2), 2002 139</p>
<p>Compatible parasitic interactions (43-46) and Resistance breeding against sedentary nematodes (47-52) CCN and RLN from landrace materials and conventional germplasm. CCN has been more extensively studied and most of the resistant sources currently identi ed possess single dominant genes. The introgression of this material into wheat breeding programmes will be discussed, par- ticularly with reference to the application of molecular tools. With further understanding of the distribution and importance of both CCN and RLN, the usability of these resistant sources should reduce losses caused by these ne- matodes. 050 Resistance in soybean to soybean cyst nematode, Heterodera glycines Greg N OEL United States Department of Agriculture, Agriculture Research Service, Department of Crop Sciences, University of Illinois, Urbana, IL 61801, USA g-noel1@uiuc.edu Soybean cyst nematode (SCN), Heterodera glycines , was found in the USA in 1954, and breeding programs soon were initiated. The source of resistance in the rst resistant cultivars was Peking, which was obtained in China. Subsequent sources of resistance incorporated into commercial cultivars include, PI88.788, PI90.763, PI209.332, all of which also originated in China. The high level of genetic variability within and among populations of SCN has proved problematic to soybean breeders and to farmers. In 1991, germplasm was released that incorporated resistance from PI437.654, which was collected in the Amur region of Russia and highly resistant to most populations of SCN. Classical breeding techniques were used exclusively until the late 1990s when marker-assisted selection using PI437.654 resistance was developed and is now being utilised in several breeding programs. Genes, rhg 1 – rhg 3 , and Rhg 3 – Rhg 5 , have been reported to be involved in expressing resistance in soybean to SCN. Some genes are linked and multiple alleles may be involved in expressing resistance. Monoculture of resistance has not proven durable, but gene deployment may offer long-term sustainable control of SCN. 051 Sustainability and mechanisms for durable use of resistance to control sedentary nematodes Roger C OOK Institute of Grassland and Environmental Research, Aberystwyth, Ceredigion SY23 3EB, Wales, UK roger.cook@bbsrc.ac.uk Evidence from three cyst nematode crop pests (of small grain cereals, Heterodera spp.; soybeans, H. glycines and potatoes, Globodera spp.) will be used to emphasise the signi cance of the relationship between the zone of plant nematode co-evolution and the cropping areas in which resistance is used. The impacts of these relationships on durability of resistance provide important lessons for the two approaches likely to be of value in enhancing durability in agriculture. These are either seeking to imitate sustainable natural metapopulation dynamics or an intensive on-going management of gene deployment. Both are technically feasible with modern plant breeding technologies, but the latter requires substantial continuing R&D investments, only likely to be justi able in intensive agricultural systems where nematodes cause prominent and economically signi cant crop loss. This latter situation is likely to be more widespread in relation to root-knot nematodes, and an attempt will be made to consider how the biology and co-evolutionary histories of these nematodes may indicate approaches to use and management of resistance so as to enhance its durability. 052 Breeding for durable resistance to RKN in perennials: a European initiative for Prunus rootstocks Daniel E SMENJAUD INRA, Unité Interactions Plantes-Micro-organismeset Santé Végétale, B.P. 2078, 06 606 Antibes cedex, France esmenjau@antibes.inra.fr Breeding for durable resistance in Prunus rootstocks is a challenging task since the long generation time increases the risk for resistance breaking. The breeding strategy is based on the selection and pyramiding of major genes conferring when possible a high-level, wide-spectrum and heat-stable resistance. Screening among Prunus species and accessions for appropriate resistance sources was performed through a rst EU project from 1993 to 1997. Some Myrobalan (M) plum accessions resisted all RKN species, even under durable inoculum pressure and high temperatures, due to single major genes with a complete spectrum, termed Ma , recently considered as allelic. By contrast, peach (P) and almond (A) sources expressed near-complete or incomplete spectra. In a second EU 140 Nematology</p>
<p>Symposium abstracts project (1999-2003), breeding for a new generation of interspeci c rootstocks, of the type M £ P, M £ A and M £ (P £ A), based on the pyramiding of one Ma allele and R genes from peach or almond is being performed for all Prunus species. In order to develop marker-assisted selection (MAS), location of the R genes using SSR markers from a European reference Prunus map and a BSA positional approach are carried out. Ma (LG7) and at least one peach gene (LG2) are independent. Several SCAR or AFLP markers located less than 0.5 cM or cosegregating with the Ma1 allele are available for MAS of all interspeci c crosses. 053 Molecular phylogenies of plant and entomoparasitic nematodes: congruence and incongruence with morphological and biological data Sergei S UBBOTIN 1 ; ¤ , Dieter S TURHAN 2 and Maurice M OENS 3 1 Institute of Parasitology of RAS, Leninskii prospect 33, Moscow, 117071, Russia 2 Biologische Bundesanstalt, Institut für Nematologie und Wirbeltierkunde, Toppheideweg 88, 48161, Münster, Germany 3 Crop Protection Department, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ s.subbotin@clo.fgov.be One of the exciting developments in nematology during the last years has been the application of nucleic acid data analysis to problems of systematics of certain groups. In many cases, molecular data con rm the monophyly of species groups recognised by morphological studies. In other cases, the molecular data reveal taxa of which the phylogenetic relationship based on the morphology seems to be problematic. Molecular data put more light on problems of species boundaries and co-evolution of nematodes with their hosts. The early presumption that phylogenetic trees based on molecular data would more precisely re ect the true phylogeny than morphological data seems to be wrong. Analyses of in uence of alignment or tree building methods on phylogenies showed that molecular data could be subjected to many problems. Congruence and incongruence of results of analyses of molecular and morphological data sets and the possible reasons for con icts are discussed with examples of plant-parasitic nematodes from the family Heteroderidae, Anguinidae, Longidoridae, and entomoparasitic nematodes of the Tylenchida and the families Steinernematidae and Heterorhabditidae. 054 Effect of Oxycom on growth of tomato and reproduction of Meloidogyne incognita Safdar A. A NWAR ¤ and M.V. M C K ENRY University of California, Riverside, CA 92521, USA ¤ anwar@uckac.edu Single or multiple applications of Oxycom, peroxyacetic acid plus various biocontrol agents, were compared on 15- day-old susceptible tomato inoculated with 1500 second stage juvenile (J2) M. incognita. Forty pots were dipped into 2500 ppm (v/v) Oxycom, and 20 in water. Twenty of the 40 pots received four additional Oxycom applications at 10-day intervals. Plants were harvested at 60 days after inoculation to assess the effect of treatments on plant growth, nematode development and reproduction. A single treatment of Oxycom just prior to nematode inoculation signi cantly increased tomato top weight but not other growth parameters. Associated with plant growth bene t was a signi cant increase in the number of root-knot females. Multiple treatments of Oxycom signi cantly reduced leaf area, top weight and root weight while signi cantly increasing the number of galls, females and J2 per plant or per g root. This study demonstrates that Oxycom stimulates plant growth and earlier fruiting while hastening nematode development. Proper timing and frequency of applications is important. No treatment reduced nematode population levels in this 60-day trial. 055 A new system for Nematoda: combining morphological characters with molecular trees, and translating clades into ranks and taxa Paul D E L EY 1 ; ¤ and Mark B LAXTER 2 1 Department of Nematology, University of California – Riverside, Riverside, CA 92521, USA 2 Institute of Cell, Animal and Population Biology, University of Edinburgh, Ashworth Laboratories, Kings Buildings, Edinburgh EH9 3JT, Scotland, UK ¤ pdeley@citrus.ucr.edu We recently proposed a new classi cation for the phylum Nematoda, based primarily on phylogenetic hypotheses resulting from small subunit rDNA sequence analysis. The strength and weaknesses of this new system are discussed with particular regards to ranks and names of nematode clades. As almost 2 years have passed since we nished writing the original manuscript, we also provide a timely update on the implications of phylogenetic analyses conducted in the past 2 years, and improve Vol. 4(2), 2002 141</p>
<p>Quarantine Nematodes (56-58) and Organic amendments for the management of plant parasitic nematodes (59-65) or correct our system where appropriate. We emphasise the importance of disentangling the earliest branches of the nematode tree, and discuss various scenarios with some tantalising implications for our understandingof the morphology and ecology of the earliest nematodes. 056 Measures to avoid new introduction of quarantined nematodes into Brazil and the spread of non-regulated quarantine nematodes Odilson Luiz R IBEIRO E S ILVA National Plant Protection Organization of Brazil, MAPA/SDA, Annexo B, Sala 307, CEP 70043-900 Brasilia, DF, Brazil odilson@agricultura.gov.br The Brazilian National Plant Protection Organization is issuing a number of new actions and regulations to avoid introductions of quarantine pests in the country and among them quarantinenematodes. A new quarantinepest list based on technical justi cation and pest risk analysis is available; an integrated electronic system to detect pests is starting to be used in the main points of entry in the country; new laboratories, quarantine stations and centres for conducting pest risk analysis are in the process of accreditation to facilitate inspections at the points of entry. All the 27 rules with general requirements to import commodities from all countries are in the process of being replaced by measures that will be based on pest risk analysis related to the origin and to the product. Besides that, an expert group has been working for more than 3 years to determine the tolerance levels for non-quarantine regulated pests for plants for planting,and new regulations on that matter will be in force soon. 057 Dilemmas for the quarantine diagnostician and taxonomist in the 21 st Century Sue H OCKLAND Invertebrate Identi cation Team, Plant Health Group, Central Science Laboratory, Sand Hutton, York, YO41 1LZ, UK s.hockland@csl.gov.uk During the last century, many nematologists were in- volved in the golden era of identi cation and many type specimens were stored in key institutes to serve as ref- erence points for future diagnosticians and taxonomists. The basis of identi cation was the ability to distinguish a new species from all others that had preceded it by recognising signi cant variation of critical morphological characters. The demise of such skills and the lack of re- sources for curation have led to concerns for the whole basis of the quarantine identi cation, despite the recent development of molecular techniques which have been hailed as the resolution to this problem. However, there remains a lack of robust, reliable methods using DNA for the immediate distinction of listed species from all oth- ers that might reasonably occur in world trade. Increasing demands for quality accreditation procedures and the re- nement of computer-based imagery are stimulating new ways of providing evidence of statutory ndings, and may prove to be the salvation of many national collections, turning many into a world-wide resource. 058 Quarantine nematodes or invasive alien species? David M C N AMARA European and Mediterranean Plant Protection Organization, Paris, France mcnamara@eppo.fr The Convention on Biodiversity (CBD) has recently been developed as a global agreement with the overall aim of ensuring the maintenance of biological diversity throughout the world. One of the main thrusts of the CBD is to prevent the transfer, by human activity, of species of plants or animals from one part of the world to another. Species that are transported (or transportable) are referred to as ‘invasive alien species’ and can be any type of plant or animal species that could disrupt ecosystems, habitats or species. As such, the concept of invasive species overlaps with the long-established ‘quarantine pest’. Plant quarantine services in many countries are reacting to these developments by expanding the range of organisms for which they have responsibility, beyond the pests of economically important crops. The consequences for nematology will be discussed and could include the need for study of nematode pests of wild plants, the ecology of non-plant-parasitic nematodes and the effects of biocontrol nematodes on natural ecosystems. 059 Organic amendments for the management of phytonematodes: enhancing natural biological control José A. C HAVARRÍA -C ARVAJAL 1 ; ¤ , Edwin A CEVEDO 2 , Carlos F LORES 3 , Nidia V YCENTE 1 , Luis S ILVA -N EGRÓN 1 and Evelyn R OSA 1 1 Department of Crop Protection, Mayagüez Campus, University of Puerto Rico, P.O. Box 9030, Mayagüez, 00681-9030, Puerto Rico 142 Nematology</p>
<p>Symposium abstracts 2 Department of Agronomy and Soils, Isabela Substation, Isabela, 00662, Puerto Rico 3 Department of Horticulture, Isabela Substation, Isabela, 00662, Puerto Rico ¤ jachavar@hotmail.com Organic amendments are useful in plant disease manage- ment because they suppress pathogen populationsthrough production of toxic substances during decomposition,and by alterations on soil microbial ecology. However, little information is available on the mode of action of these materials, especially how they affect activities and popu- lations of soil microorganisms. Interactions between an- tagonistic microorganisms and plant pathogens are wide- spread in nature and organic amendments may be useful to enhance naturally occurring biological control and re- duce diseases caused by nematodes. Experiments were conducted during the last 5 years in Puerto Rico that showed the value of organic matter to suppress nema- tode populations under tropical conditions. Changes in populations of microorganisms associated with use of or- ganic matter were studied. The use of organic amend- ments improved the activity of microorganisms associated with the rhizosphere of tropical crops. We are focusing on the exploitation of microorganisms promoted by organic amendments as sources of biological control agents for phytonematodes.This approach may be a practical tool to reduce the dependenceon synthetic pesticides and to miti- gate the environmentalcontamination produced by the in- tensive use of chemicals. 060 Biofumigation and nematode control in the Mediterranean region Antonio B ELLO ¤ , J. Antonio L ÓPEZ -P ÉREZ , Avelino G ARCÍA -Á LVAREZ and Rafael S ANZ Dpto Agroecologia, Centro de Ciencias Medioambientales, CSIC, Serrano 115 dpdo, 28006 Madrid, Spain ¤ antonio.bello@ccma.csic.es Biofumigation is de ned as the effect from the gases produced during the biodecomposition of organic matter for controlling plant pathogens. Biofumigant action is indicated as a general property of organic matter, of animal manure as well as green manure or agroindustrial remains. Its effectiveness is similar to conventional fumigants, at the same time as it improves soil chemical, physical and biological characteristics. The scienti c bases for biofumigation are established, differentiating it from the use of organic matter as an amendment, with regard to the characteristics of the biofumigant and the method of application. Cost of transportation is shown as its principal limiting factor. Differences are established between it and other control alternatives such as solarisation, ooding and biosterilisation, although they can be considered complementary. The effectiveness of biofumigation increases with time, when included in an integrated production system, which should take into account the speci c characteristics of areas with a Mediterranean climate. It is concluded that biofumigation is a control alternative based on the use of local resources and that it reduces environmental impact from agriculture and increases the quality of agricultural production. 061 Soil solarisation, nematicide and chicken compost for root-knot nematode control in carrot crops in Brazil Claudio M.G. O LIVEIRA 1 ; ¤ , Roberto K. K UBO 1 , Mario M. I NOMOTO 2 , Flávia R.A. P ATRÍCIO 1 , Osvaldo C ABRAL 3 and Benedito C. B ARROS 1 1 Instituto Biológico, Caixa Postal 70, Campinas, SP, 13001-970, Brazil 2 Universidade de São Paulo, Escola Superior de Agricultura ‘Luiz de Queiroz’, Caixa Postal 09, Piracicaba, SP, 13418-900, Brazil 3 EMBRAPA Meio Ambiente, Caixa Postal 69, Jaguariúna, SP, 13820-000, Brazil ¤ colive@scri.sari.ac.uk A eld experiment was performed in sandy soil, naturally infested with Meloidogyne incognita and M. javanica, in Piracicaba, SP, Brazil, to assess the effectiveness of soil solarisation, chicken compost (20 t/ha), carbofuran 100G (40 kg/ha), and combinations of these treatments for the control of root-knot nematodes in carrot cv. Aline. Soil solarisation was performed over 69 days during the warmest months of summer of 2000/2001, using a 100 ¹ m polyethylene plastic lm as soil covering. The soil temperature in solarised plots was 8-12 ± C higher than in the non-solarised. Maximum soil temperatures were recorded in solarised soil combined with chicken compost and reached 77, 56 and 46 ± C, at depths of 5, 10 and 20 cm. Population densities of M. incognita and M. javanica were controlled by both soil solarisation alone and combined with chicken compost or carbofuran. Carrot cv. Aline yield was signi cantly increased by combination of solarisation and chicken compost plus nematicide application before planting. Vol. 4(2), 2002 143</p>
<p>Quarantine Nematodes (56-58) and Organic amendments for the management of plant parasitic nematodes (59-65) 062 Green manure amendments and management of root-knot nematode on potato in the Paci c Northwest of USA Ekaterini R IGA 1 , Hassan M OJTAHEDI 1 , Russell E. I NGHAM 2 and Andrew M. M C G UIRE 3 1 Washington State University, IAREC, 24106 N. Bunn Rd., Prosser, WA 99350, USA 2 Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA 3 Washington State University Cooperative Extension, P.O. Box 37, Ephrata, WA 98823, USA ¤ riga@wsu.ed Meloidogyne chitwoodi, a serious pest of potatoes in the Paci c Northwest (PNW) of the USA, blemishes potato tubers and renders them unmarketable. Currently, this nematode is effectively controlled by an environmentally hazardous and costly fumigant, Telone II. As an alternative to fumigation, green manure cover crops including rapeseed, white mustard, and sudangrass, and the organic amendments canola seed meal, and milkweed seed meal, have been used to control M. chitwoodi in the PNW. Green manures and seed meals alone have reduced the nematode impact on potatoes by 50-80%. In addition, the above amendments have been used successfully in combination with contact nematicides, such as ethoprop, and provided control against M. chitwoodi at a level comparable to soil fumigation. Our studies demonstrated that the use of green manures together with 2 years of crop rotation controlled M. chitwoodi to acceptable levels without the use of a nematicide. However, studies from other regions of the USA have shown that the amendments failed to control other species of root-knot nematodes. These con icting results indicate that amendments should be utilised according to local environmental conditions. Management with green manures may be more successful in short or cool growing seasons where nematode damage potential is lower. In addition, we found that green manures improve soil physical characteristics, especially water in ltration and penetration resistance. 063 Impact of paper mill residual amendments on Pratylenchus penetrans in a vegetable rotation A. M AC G UIDWIN ¤ , A. R EID -R ICE , L. C OOPERBAND and D. R OTENBERG Department of Plant Pathology, University of Wisconsin, Madison, WI, USA; Department of Soil Science, University of Wisconsin, Madison, WI, USA ¤ aem@plantpath.wisc.edu Amending soil with paper mill residuals is a strategy to improve soil fertility and minimise the loss of nutrients and pesticides. We initiated an experiment in 1998 to study short- and long-term changes in the chemical, physical and biological properties of soil after adding paper mill residual amendments to the plots every spring. The treatments were two rates of fresh paper mill residuals, paper mill residuals composted alone, paper mill residuals composted with bark, and a non-amended control. The experiment, a randomised complete block with ve replications of each amendment treatment, was planted with potato in 1998, snap bean in 1999, cucumber in 2000, and potato in 2001. Population densities of Pratylenchus penetrans were 88 nematodes per 100 cm 3 soil at the start of the experiment. Root lesion population densities declined in the control plots and stayed the same or increased in amended plots from 1998 to 2001. In November 2001 P. penetrans was most abundant in the ‘high rate-composted alone’ treatment. Incidence of symptoms indicative of the potato early dying disease were also most severe for this treatment. Amended plots had a higher capacity for water retention and increased organic matter. 064 Nonchemical control of root-knot nematodes ( Meloidogyne complex ) in glasshouse conditions and Xiphinema index in the vineyard Boryana C HOLEVA 1 ; ¤ , Emil M OLLE 1 and Jordan T ZVETKOV 2 1 Faculty of Biology, University of So a ‘St. Kliment Ochridski’, 8 Dragan Tzankov blvd., 1164 So a, Bulgaria 2 Experimental Station, Septemvri, Bulgaria ¤ choleva@biofac.uni-soa.bg A group of scientists from the university of So a and the Experimental Station in Septemvri investigated more than 10 years plan residues and manufacturing industries waste products as means to avoid agrochemical for control of soil pathogens(nematodes). The last 3 years we continued the experiments with substrates and extracts from waste products of microbial industry (Biovet factory – Peshtera). The investigated products are obtained on the base of an original recycling technology. The results showed a very favorable effect and advantages for Meloidogyne complex as a signi cant reduction of L 2 , a later and weaker infection of the tomato and the cucumber roots and the total yield increased up to 62%. These substrates reduced 144 Nematology</p>
<p>Symposium abstracts very strongly the population density of Xiphinema index and stimulated several time the plant crowing and the yield. The investigated products pointed to the new possibilities of the nonchemical control of the parasitic nematodes. 065 Organic amendments as therapeutic treatment of guava trees ( Psidium guajava L.) infested with Meloidogyne incognita in Zulia State, Venezuela Ana Maria C ASASSA -P ADRÓN 1 ; 2 , Evelyn P ÉREZ -P ÉREZ , Merylin M ARÍN 2 , Casilda G ONZÁLEZ , Dubia C HIRINOS and Luis S ANDOVAL 1 1 Universidad del Zulia, Facultad de Agronomía, Instituto de Investigaciones Agronómicas, Maracaibo, Apto 15205, Venezuela 2 Departamento de Botánica, Ciudad Universitaria, Av. Ziruma, Maracaibo, Apto 15205, Venezuela ¤ casassa@cantv.net The biofumigant effect of organic amendments as a therapeutic treatment on 6-year-old guava trees infested with root-knot nematode was evaluated at the Centro Frutícola del Zulia-CORPOZULIA. Treatments included control (T1), 30 kg (T2), 60 kg (T3) of goat manure per tree, 30 kg (T4) and 60 kg (T5) of composted sugarcane bagasse, and combinations of 15 kg (T6) and 30 kg (T7) of each, applied every 3 months. Results after 10 months of evaluations indicated no statistically signi cant differences in Meloidogyne incognita populations. However, comparing the rst and third sampling dates, a reduction in populations could be seen, with T7 having the fewest (827 second stage juveniles (J2)/100 g soil and 10 g roots) and T1 having the most. Regarding phenological characteristics, the highest value for leaf presence was observed in T3 (60%), branching and ower buds in T7 (25 and 14%, respectively), and fruiting in T5 (24%). Preliminary results of this study suggest we should continue the evaluation of these organic amendments as an ef cient alternative for integrated pathogen control in fruit horticulture. 066 The symbiosis of Wolbachia bacteria and larial nematodes Mark J. T AYLOR Filariasis Research Laboratory, Division of Molecular and Biochemical Parasitology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool L3 5QA, UK mark.taylor@liv.ac.uk Wolbachia bacteria appear to have evolved a mutualistic symbiosis with their nematode hosts. This is in contrast to the closely related Wolbachia endosymbionts of arthropods, which display a diverse range of associations. Within the Nematoda, Wolbachia appear to be restricted to larial parasites, and molecular phylogenetic analysis suggests nematodes probably acquired their symbionts due to their intimate association with their arthropod vectors some 100 million years ago. Since then, however, there is no evidence for recent horizontal transmission between nematodes and arthropods. Wolbachia have so far been found in more than 20 species of larial nematode, with only two species appearing to be uninfected. Of those with Wolbachia, the infection appears to be ubiquitous in all individuals, developmental stages and populations throughout their global distribution. The bacteria reside in vacuoles and are restricted to the lateral cord cells and developmental stages within the female reproductiveorgans and intrauterine developmentalstages as a consequence of their vertical transmission via the egg. As larial nematodes are major pathogens of humans throughout the tropics, our research has focused on the contribution of Wolbachia to disease pathogenesis and as a novel target for antibiotic therapy. These studies show that Wolbachia endotoxin-like activity is the principal cause of in ammatory larial disease. Antibiotic therapy of larial nematodes and removal of Wolbachia results in a complete and long-term block of embryogenesis and the eventual death of the nematode. Recent studies in our laboratory suggest that the symbionts also contribute to the evasion of immunity in mammalian and vector hosts and so may be responsible for the long-term survival of larial nematodes. 067 Coevolution between Fergusobia and Fergusonina mutualists Robin M. G IBLIN -D AVIS 1 ; ¤ , Sonja J. S CHEFFER 2 , Kerrie A. D AVIES 3 and W. Kelley T HOMAS 4 1 Fort Lauderdale Research and Education Center, University of Florida/IFAS, 3205 College Ave, Davie, FL 33314, USA 2 USDA-ARS Systematic Entomology Lab, 10300 Baltimore Ave, Beltsville, MD, USA 3 Department of Applied and Molecular Ecology, Adelaide University, PMB 1 Glen Osmond, SA, Australia 5064 4 Hubbard Center for Genome Studies, University of New Hampshire, 35 Colovos Road, Durham, NH 03820, USA ¤ giblin@u.edu Vol. 4(2), 2002 145</p>
<p>Nematodes as mutualists (66-68) and Incompatible parasitic interactions (69-72) The contemporary associations between Fergusobia ne- matodes (Neotylenchidae) and Fergusonina ies (Fergu- soninidae) represent the only putative example of nema- tode and arthropod-associated mutualism. The nematode appears to induce a bud or leaf gall that both organisms use while the y provides gall maintenance, dispersion, and sustenance for the nematode. Based upon molecular analysis, this is a potentially large monophyletic radia- tion of more than 50 mostly undescribed species of ne- matodes and ies that exhibit a high degree of host speci- city within the Australasian Myrtaceae (mostly Lep- tospermoideae; e.g ., Eucalyptus , Corymbia , Angophora and Melaleuca ). The Agromyziidae (with no known ne- matode associates) is the putative sister group to the Fer- gusoninidae. Fergusobia could have evolved from para- sitic nematodes similar to present day Howardula that parasitised the cyclorrhaphan stem ancestor of Ferguson- ina ies and developed a plant-parasitic association that provided a mutual bene t to y host and nematode. Al- ternatively, Fergusobia could be related to present day anguinids that produced aboveground galls and devel- oped an association with an agromyzid ancestor. In ei- ther case, the evolution of the host-parasite interaction requires that host resistance and virulence be moderated. Contemporary examples of commensal and parasitic asso- ciations between nematodes and insects are used to gener- ate hypotheses about how such an association could have evolved and is maintained. 068 Evolutionary attenuation of virulence in Drosophila -parasitic nematodes John J AENIKE 1 ; ¤ and Steve P ERLMAN 2 1 Department of Biology, University of Rochester, Rochester, New York 14627, USA 2 Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA ¤ joja@mail.rochester.edu Virulence is of central importance in host-parasite interactions, yet little is known about how it changes over extended evolutionary periods. Four species in the testacea species group of Drosophila were experimentally infected with sympatric and allopatric nematodes in the Howardula aoronymphium species complex, and the effect of parasite infection on host tness was quanti ed. The fertility of infected Drosophila females appears to be determined solely by the host, with some species being sterilised and others not, regardless of the source of the nematodes. Reductions in host adult lifespan and male fertility, however, depend on both the host and the parasite. In particular, survival of two Drosophila species was drastically reduced when infected with an allopatric parasite. Thus, virulence is evolutionarily labile in associations between Drosophila testacea group species and their Howardula parasites. The high level of virulence manifested in some host-parasite combinations is due to a lack of resistance in the hosts, perhaps as a result of recent host colonisation by Howardula . These results provide evidence for a continuum of host- parasite interaction, with virulence initially high, followed by evolution of the parasite to reduce the rate of host mortality, and evolution of the host to resist parasite- induced sterility. 069 R-gene homologues in potato confer resistance against distinct pathogens: a virus and a nematode Erin B AKKER 1 ; ¤ , Joke VAN V LIET 1 , Hein O VERMARS 1 , Geert S MANT 1 , Hans S ANDBRINK 2 , Edwin VAN DER V OSSEN 2 , Jaap B AKKER 1 and Aska G OVERSE 1 1 Laboratory of Nematology, Wageningen University, Binnenhaven 5, 6709 PD Wageningen, The Netherlands 2 BU Genomics, Plant Research International, The Netherlands ¤ erin.bakker@nema.dpw.wau.nl Genome analysis of a single R-gene cluster in potato revealed two highly homologous resistance genes, Gpa2 and Rx1 . The two genes confer resistance to fully unrelated pathogens, namely the potato cyst nematode Globodera pallida and the potato virus X. To get more insight into the evolutionary relationship between the two resistance genes, three new homologues mapping to the same cluster on chromosome 12 of the diploid potato clone SH83 were identi ed by using a single LRR-based primer pair. cDNA analysis resulted in the identi cation of the ORFs for two out of the three new homologues. To investigate the diversi cation process within this cluster, DNA sequence data were analysed; the remarkable sequence conservation between the effector domains of Gpa2 and Rx1 points at the activation of a similar resistance mechanism. On the other hand, infection studies and histological observations revealed a relatively slow resistance response for Gpa2 , while Rx1 results in an extreme resistance. To gain more insight in the mechanism underlying nematode and virus resistance structure-function analysis of GPA2 and RX1 are currently under investigation. 146 Nematology</p>
<p>Symposium abstracts 070 Resistance to soybean cyst nematode: an Xa 21-like gene family that requires possible dimerisation for signal transduction Khalid M EKSEM , Aziz J AMAI , Eliza R UBEN , Kanokporn T RIWITAKORN , Hirofumi I SHIHARA , Kimberly Z OBRIST and David A. L IGHTFOOT Department of Plant, Soil and General Agriculture, Room 176, Southern Illinois University at Carbondale, Carbondale, IL 62901-4415, USA In the soybean ( Glycine max (L.) Merr.) cv. Forrest, disease resistance inheritance to the soybean cyst nematode Heterodera glycines Ichinohe (SCN) race 3 (Hg 0 ) was demonstrated to be digenic, and conditioned by the presence of both the Rhg 1 and Rhg 4 genes. A high-density genetic map was constructed for the two chromosomal regions carrying resistance loci to SCN. An integrated physical genetic map was constructed around the Rhg 1 and Rhg 4 loci. Candidate gene sequences for Rhg 1 and Rhg 4 have been isolated from soybean cv. Forrest BAC clone 73P6 and 100B10. Shotgun gene sequencing and cDNA hybridisation identi ed two genes with high homology to the Xa 21 rice disease resistance gene and to an Arabidopsis receptor-like kinase family, which contain three functional domains each. Domains within the 854 residues of Rhg 1 show the presence of 12 extracellular leucine rich repeats, a trans-membrane spanning domain and a kinase domain. Rhg 4 shares the same structure, with a long peptide sequence of 894 residues and has low amino acid homology to the Rhg1 peptide. An active-dimerisation form of the Rhg1- Rhg4 protein is suggested from the interaction studies for the activation of the signal transduction pathways for resistance to SCN. 071 Functional analysis of the Mi-1 gene V.M. W ILLIAMSON Department of Nematology, University of California, Davis, CA 95616, USA vmwilliamson@ucdavis.edu The tomato gene Mi-1 confers resistance against several species of root-knot nematodes and against speci c isolates of potato aphid. Mi , like many plant resistance genes, encodes a protein with an apparent nucleotide binding site and a C-terminal string of loosely conserved leucine-rich repeats. Resistance is characterised by a localised necrosis or hypersensitive response. The phenotypes of domain swaps and single nucleotide changes between Mi-1.2 and Mi-1.1 , a homologue that does not confer resistance against nematodes, have been tested in two assays. Nematode resistance was tested in transgenic roots, and ability to induce a hypersensitive response was tested after transient expression in Nicotiana benthamiana leaves. Analysis of reciprocal swaps has identi ed regions of the gene that are important for nematode recognition and for signaling the defence response. Our results indicate that intramolecular interactions of the Mi -protein are involved in its regulation. We have also used the transient expression system to investigate the role of signaling molecules and plant hormones in the resistance response. 072 Understanding the genetical and molecular basis of (a)virulence in the root-knot nematode Meloidogyne incognita Philippe C ASTAGNONE -S ERENO INRA Unité IPMSV, BP2078, 06606 Antibes cédex, France pca@antibes.inra.fr Plant resistance is currently the most effective and envi- ronmentally safe method to control root-knot nematodes. Resistance genes generally act by inducing an hypersen- sitive reaction at or near the infection site, that prevents the parasite installation and/or reproduction.However, the emergence of virulent biotypes able to overcome the plant resistance genes may constitute a severe limitation to this control strategy. To investigatethe molecular determinants of (a)virulence in root-knot nematodes, we have been de- veloping differential strategies based on the selection and subsequent comparative analysis of pairs of Meloidogyne incognita near-isogenic lines, just differing in their abil- ity to reproduce or not on tomatoes bearing the Mi resis- tance gene. The objective of these approaches is to iden- tify genes differential or differentially expressed between the avirulent and virulent lines. Recent results will be pre- sented, and discussed in relation with the mode of re- production of the nematode, i.e. , mitotic parthenogenesis. Elucidating the genetical and molecular mechanisms in- volved in the selection process of virulent nematodes from avirulent ones should have important consequencesfor the management and durability of natural resistance genes in the eld. 073 Nematode biodiversity research – current status and future promise Vol. 4(2), 2002 147</p>
<p>Nematodes as mutualists (66-68) and Incompatible parasitic interactions (69-72) Klemens E KSCHMITT Justus Liebig University, IFZ – Department of Animal Ecology, H.-Buff-Ring 26-32, D-35392 Giessen, Germany Klemens.Ekschmitt@allzool.bio.uni-giessen.de The presentation attempts an evaluation of the current status of nematode biodiversity research. Starting from an overview of how nematology is integrated in international biodiversity programmes, and from a synopsis of biodiversity-related information which has been made generally accessible to the scienti c public, three major questions are addressed: i ) what are the drivers of nematode diversity; ii ) how tightly is nematode diversity linked to environmental factors; and iii ) what can we therefore expect to be the information content of nematode diversity? Knowledge gaps and research priorities are speci ed and discussed. 074 Nematode survey in Costa Rican conservation areas Alejandro E SQUIVEL Universidad Nacional de Heredia (U.N.A), Apartado postal 86-3000 Heredia, Costa Rica and Instituto Nacional de Biodiversidad (INBio), Apartado postal 22-3100, Santo Domingo de Heredia, Costa Rica aesquive@una.ac.cr;aesquive@inbio.ac.cr The Instituto Nacional de Biodiversidad (INBio) is a non-pro t scienti c institution with social orientation, created in 1989, whose main mission is to promote a new awareness of the value of biodiversity and, thereby, achieve its conservation in Costa Rica. The nematode subprogram was initiated of cially in 1998 in close cooperation with the Universidad Nacional of Heredia and nanced by the Netherlands government. We conducted a nematode inventory in ve conservation areas of Costa Rica, chosen because they contain the most representative and diverse ecosystems of the country. Several hundreds of samples were collected and referenced with a GPS navigator. All contrasting morphotypes from each sample were represented and stored permanently on Cobb’s slides. The reference nematode collection of INBio contains 17 757 specimens, distributed as follows: Dorylamida (39.3%), Rhabditida (18.7%), Araeolaimida (10.1%), Tylenchida (9.3%), Enoplida (9.1%), Mononchida (8.2%), Chromadorida (2.1%), Aphelenchida (1.9%), Monhysterida (1.0%) and Mermithida (0.2%). Most of the collection is identi ed at genus level; only 7% is identi ed at species level of which 14 are new to science. The interaction with international taxonomists is essential to both train INBio staff and generate knowledgerelated to tropical nematode diversity. 075 Nematode diversity in Dutch soils, from Rio to Dutch Soil Quality Network (DSQN) Ton S CHOUTEN Laboratory for Ecotoxicology, National Institute for Public Health and the Environment, P.O. Box 1, 3720BA Bilthoven, The Netherlands aj.schouten@rivm.nl Analysis of nematode fauna has been part of a Dutch monitoring network since 1993. It has the advantage that available comprehensive abiotic measures can be combined with biological characteristics. The monitoring network consists of 200 locations, representing ten major types of soil type/soil use combinations. Sampling locations are chosen in proportion to the form of land- use because the network aims to give a general picture of biological soil quality in the Netherlands. Seventy percent of the Dutch soil area is in agricultural use. Therefore, 180 locations are situated on different types of farms, with 40 sampled per year on a cycle of 5 years. After the biodiversity conference of Rio de Janeiro, the Dutch government rati ed the treaty, and concluded that functional diversity aspects of non-natural soils need more attention and quality standards. In 1999, the biological soil monitoring was extended to a foodweb- based programme. The nematode fauna is an important component due to the ecological (feeding) groups that can be distinguished. In the second round of the monitoring programme, 100 biological farms were added to serve as a reference for regular farming systems. A method for comparison and quality assessment expressed in a Soil Quality Index is under development. 076 Nematode component of the Fauna Europaea project Tom B ONGERS 1 ; ¤ and Wouter L OS 2 1 Laboratory of Nematology, Wageningen University, P.O. Box 8123 NL-6700 ES Wageningen, The Netherlands 2 Zoological Museum Amsterdam, P.O. Box 94766 NL-1090 GT Amsterdam, The Netherlands ¤ tom.bongers@nema.dpw.wau.nl The Community Biodiversity Strategy of the European Commission provides a framework for the development 148 Nematology</p>
<p>Symposium abstracts of Community policies and instruments to comply with the Convention of Biological Diversity. Fauna Europaea contributes by identifying and cataloging components of European biodiversity to serve as a basic tool for science and conservation policies. Fauna Europaea will assemble a database of scienti c names and distribution of all living multicellular European land and fresh-water animals, including nematodes. Marine nematodes are included in a ‘sister’ project, the European Register of Marine Species (ERMS). In anticipation of a Key to the European Nematodes , the basal species list ( Nematoden van Nederland ) was extended to include the whole of Europe. Currently, the nematode database includes a total of 2500 species, including the full name, author, date, original genus, main synonyms and geographic distribution. Classi cation is based on the most recent, generally accepted standards. Published records or personal communications for material deposited and available in a public nematode collection must support database entries. Geographic information will be provided for each species according to ISO-TDWG standards; the reporting region will include Europe, Macaronesian islands, Cyprus, Franz Josef Land and Novaya Zemlya. Species recorded from non- eld locations including glasshouses and aquariums will not be included. 077 Past and present status of nematode community indicators Ewa D MOWSKA ¤ and Krassimira I LIEVA -M AKULEC Institute of Ecology, Polish Academy of Sciences, Dziekanow Lesny, 05-092 Lomianki, Poland ¤ edmowska@poczta.onet.pl Differences in sensitivity of nematodes towards some chemicals have been recognised for nearly four decades. Initially, single species or taxonomic groups were con- sidered, followed by parameters of whole communities to measure different properties of natural and disturbed ter- restrial ecosystems. A short overview of nematode com- munity indices will be presented, progressing from those considered traditional, relatively simple, and widely ap- plied in environmental studies ( e.g ., abundance, richness, diversity, similarity and constancy) to those considered more sophisticated ( e.g ., Maturity index and its modi ca- tions) and speci c to nematodes ( e.g ., proportions among trophic groups). Emphasis will be placed on indices used most often. Their contribution to understanding the func- tioning of soil ecosystems ( e.g ., nature of decomposition pathways, N-mineralisation) in different situations ( e.g ., enrichment, stress and succession) is critiqued. Applica- bility of indices to assessment of soil quality and associ- ated sampling methods will be discussed relative to ge- ographical scale, soil and vegetation type. Fundamental constraints and research priorities are identi ed: i ) clar- ifying trophic af nity of some species; ii ) integrating morphological,ecological and molecular approaches; and iii ) intensifying long-term studies in natural and disturbed environments. 078 Nematode faunal analyses to assess food web enrichment and connectance Howard F ERRIS 1 ; ¤ , Tom B ONGERS 2 and Ron D E G OEDE 3 1 Department of Nematology, University of California, Davis, CA 95616, USA 2 Laboratory of Nematology, Wageningen University, P.O. Box 8123, 6700 ES Wageningen, The Netherlands 3 Sub-department of Soil Quality, Wageningen University, P.O. Box 8055, 6700 EC Wageningen, The Netherlands ¤ hferris@ucdavis.edu. The cp classi cation recognises that nematode taxa with anatomical and physiologicalcommonalities are probably similarly adapted to speci c environmental conditions. Functional guild analysis, which integrates cp-scaling with food sources, reveals that some guilds respond opportunistically to enrichment while others represent the presence of higher trophic connectance in the food web. This dichotomy was portrayed graphically in cp triangles as the proportional representation of enrichment opportunists (cp 1), general opportunists (cp 2) and taxa indicating higher connectance (cp 3-5). Confounded in the calculation of cp triangles is interdependence of the axes; proportionality of the three groupings to the whole nematode fauna requires that increase in food web structure (cp 3-5 taxa) concomitantly decreases the enrichment indicator (cp 1 taxa). The categorical separation of nematode taxa into ve cp classes does not imply unit increments in r or K characteristics. We use body size and growth rates to weight the importance of enrichment indicators and estimates of corresponding food web connectance to weight the importance of structure indicators. We consider cp 2 taxa basal to both trajectories and calculate position along the enrichment and structure axes of a faunal diagram independently as the weighted ratios of the indicator and basal taxa. 079 Selection of sentinel taxa and biomarkers Vol. 4(2), 2002 149</p>
<p>Diversity and indicators (73-80) and Morphology and development (81-84) Deborah A. N EHER 1 ; ¤ , Daniel A. F ISCUS 2 and Fafeng L I 1 1 University of Toledo, Department of Earth, Ecological and Environmental Studies, Mailstop 604, 2801 W. Bancroft St, Toledo, OH 43606, USA 2 University of Maryland Center for Environmental Science Appalachian Laboratory, 301 Braddock Road, Frostburg, MD 21532, USA ¤ deborah.neher@utoledo.edu Nematode community indices would be more feasible for use in environmentalmonitoring programmes by reducing the number of genera that need to be enumerated and identi ed. This could be achieved by narrowing indices to include only sensitive or tolerant genera or species while eliminating ambiguous ones. Identi cation of sentinel taxa can be achieved by employing a combination of tools. For example, multivariatestatistics can help identify taxa that demonstrate relative tolerance or sensitivity to physical and/or chemical/nutrient types of disturbance. Life history characteristics of taxa meeting these criteria can be veri ed in empirical studies to evaluate and recommend re nement in coloniser-persister weights employed in maturity indices. Veri cation of coloniser- persister values can be achieved using independent molecular biomarkers. Once sentinel taxa are identi ed, molecular diagnostic tools are possible. Availability of commercial kits then becomes approachable to non- specialists and cost-effective (time and labour) for implementing nematode bioindicators within large-scale environmental monitoring programmes. 080 A nematode reference database as an instrument for biological soil assessment: a case study from the Netherlands R.G.M. DE G OEDE 1 ; ¤ , T. B ONGERS 1 , W.A.M. D IDDEN 1 , P. D OELMAN 2 , H. K EIDEL 3 , F. K ERKUM 4 , R. K NOBEN 5 , T. S CHOUTEN 6 , J. VAN DER W AARDEN 7 and M. W AGELMANS 7 1 Sub-department of Soil Quality, Wageningen University, P.O. Box 8005, 6700 EC Wageningen, The Netherlands 2 Doelman Advisory 3 Blgg 4 RIZA 5 Royal Haskoning 6 RIVM 7 Bioclear ¤ Ron.deGoede@BB.BenP.WAU.NL Traditionally, assessments of ecological risks of soil pol- lution are based on chemical analyses compared to a set of standards. Recently, in the Netherlands, investigations were initiated to explore the possibility of including bi- ological indicators in ecological risk assessment proce- dures. Nematodes are among the soil fauna groups that have promising characteristics as indicators for soil qual- ity ( i.e ., ubiquitous,high species diversity, sensitive to var- ious kinds of soil disturbances, speci c nematode-based indicators). However, interpretation depends on compari- son with undisturbed controls or references. As local ref- erence sites or data are often unavailable, there is demand for a nation-wide reference system. In the present project, we built a database (DAWACO Nematodes) of 1600 ne- matode fauna samples from which all taxa were identi- ed. The samples were collected across the country, rep- resenting a variety of soil-, vegetation- and land-use types between 1985 and 2001. Samples from undisturbed or ref- erence locations were analysed with multivariate analyses techniques to select clusters of samples (14 from terres- trial soils, six from aquatic sediments) with similar nema- tode fauna and habitat characteristics. Based on the sta- tistical characterisation of the composition of taxa from a reference cluster, the probability of membership of any sample requiring assessment can now be calculated and evaluated. 081 Spermatogenesis and nematode phylogeny Vladimir V. Y USHIN 1 ; ¤ and Vladimir V. M ALAKHOV 2 1 Institute of Marine Biology FEB RAS, Vladivostok 690041, Russia 2 Department of Biology, Moscow State University, Moscow 119899, Russia ¤ yushin@fromru.com Data on sperm structure and spermatogenesis are frequently discussed in the analyses of the phylogenetic relationships inside many classes of the metazoan animals with the exception of the class Nematoda. One of the reasons for this situation is a lack of studies on the relatively primitive aquatic nematodes from several important orders. Our latest observations on sperm development in free-living nematodes from the orders Enoplida (suborders Enoplina, Oncholaimina, Tripyloidina), Chromadorida (suborders Chromadorina and Cyatholaimina), Desmodorida, Araeolaimida and Monhysterida, together with the data available on many parasitic species, allow de nition of four main patterns of nematode spermatogenesis. Each pattern is distinguished 150 Nematology</p>
<p>Symposium abstracts clearly by special way of development of aberrant organelles – membranous organelles (MO) and brous bodies (FB): i ) MO and FB develop as the MO- FB complexes (most Rhabditia (Rhabditida, Strogylida, Ascaridida, Rhigonematida, Spirurida) and some of Chromadoria (Araeolaimida (including Comesomatidae) and Monhysterida); ii ) MO and FB occur but their development is asynchronous and independent (some Enoplia: Enoplida ( Enoplus, Pontonema ); Dorylaimida ( Xiphinema )); iii ) MO do not appear, only FB are developed (Tylenchida from Rhabditia, Chromadorida and Desmodorida from Chromadoria); iv ) FB do not appear, only MO are developed (Enoplia: Enoplida ( Anticoma ), Mermithida, Trichurida, Dioctophymida). Pattern of sperm development may be proposed as a new distinct cytological character for the analysis of the nematode relationships. 082 Phylogeny and ontogeny of free-living and parasitic nematodes Einhard S CHIERENBERG ¤ , Vera L AHL , Magdalena L AUGSCH and Thomas G ÖDDE Zoological Institute, University of Cologne, 50933 Köln, Germany ¤ e.schierenberg@uni-koeln.de Phylogenetic relationships between nematodes have always been discussed controversially. In recent years analysis of molecular data, particularly sequence data from genes coding for ribosomal RNA, have challenged some of the traditional taxonomic proposals based on morphological criteria. As a third means to identify characters of potential phylogenetic value, we are studying selected developmental processes during early embryogenesis. These include establishment of axial polarity, separation of soma and germline, assignment of cell fates and the pattern of gastrulation. Some of the existing differences can be readily identi ed by comparative analysis while others require experimental interference. A variety of free-living and also several parasitic species have been studied. Our results support the notion that the classical separation into Secernentia and Adenophorea is arti cial, and that at least three supertaxa should be de ned. In some cases we identi ed major differences between species considered as close relatives, questioning their present position in the phylogenetic tree. To reach a more lucent picture of nematode phylogenetic relationships, data from different approaches have to be be taken into account and the number of analysed nematode species must be increased. 083 Nematode embryology and its importance for the classi cation of higher nematode taxa Vladimir V. M ALAKHOV Department of Biology, Moscow State University, Moscow 119899, Russia vmalakhov@mtu-net.ru Investigations on the embryology of nematodes of dif- ferent taxa revealed the great variety of the development within the class. There are three principal patterns of ne- matode development.The rst one is characteristic for ne- matodes of the order Enoplida. The cleavage of the eno- plid eggs is variable. The bilateral symmetry forms rela- tively late, usually after the closing of the blastopore. The fate of the blastomeres is not determined strictly as is char- acteristic for other groups of nematodes. The second pat- tern is characteristic for nematodes of the Enoplia line of evolution with the exception of the Enoplida. This line in- cludes the orders Monochida, Dorylaimida, Mermithida, Dioctophymida and Trichurida. The cleavage of the ne- matodes of the above-mentioned orders is bilateral with early determination of the fate of blastomeres. The key feature of the second pattern is the origin of the endo- derm from the anterior blastomere of the two-cell stage. The third pattern is characteristic for the Chromadoria C Secernentea line. In this line, the egg cleavage is also bi- lateral and strictly determined, but the endoderm comes from the anterior blastomere of the two-cell stage. Three principal patterns of nematode development correspond to the main trend of nematode evolution and could be the base for a new nematode classi cation. 084 Division and fate of vulval precursor cells: is polymorphism an image of evolutionary divergence? Laure B ONNAUD ¤ , Marie D ELATTRE and Marie-Anne F ELIX Institut Jacques Monod, CNRS-Universités Paris 6 et 7, Tour 43, 2 place Jussieu, 75251 Paris cedex 05, France ¤ bonnaud@ccr.jussieu.fr In order to approach evolutionary processes of develop- mental mechanisms, we are studying development of dif- ferent nematodes at the cellular level. The cell lineage of nematodes is mostly invariant for a given species, but varies between species. We have performed a microevo- Vol. 4(2), 2002 151</p>
<p>Marketable biological control agents for plant-parasitic nematodes (85-88) lutionary approach with the nematode vulva as a model system to de ne how a cell lineage varies during evolu- tion. The vulva is formed by precursors in the ventral ep- ithelium, called Pn.p cells. Each Pn.p cell has a speci c fate, which is speci ed by cell interactions that are differ- ent in Caenorhabditiselegans and Oscheius sp. 1 CEW1. Two distinct networks of cell interactions can therefore lead to an identical pattern that forms a similar morpholo- gical structure. Moreover, the same vulva lineage charac- ters that diverge between closely related species are poly- morphic within a species (between laboratory strains). In order to understand evolutionary mechanisms of cell lin- eage variation, we performed a genetic analysis of P3.p division between strains of C. elegans . Recombinant in- bred lines show intermediate levels for the lineage char- acter. Polymorphism between two strains is therefore due to several loci. 085 Biocontrol – a route to market Dave C RUMP BioNem Ltd, 46, Chaul End Road, Caddington, Bedfordshire, LU1 4AS, UK rump@bionem.freeserve.co.uk With nematicides declining in popularity for environmen- tal reasons, and resistance not being a long-term solu- tion due to the ability of nematode populations to over- come it, there is a need for an environmentally safe con- trol measure that can give effective, long-term control of nematodes. Biocontrol has been studied for many years, with some encouraging results, and there is now mount- ing pressure to develop it towards practical application. I will be presenting the route I am taking to try and achieve this. It is notoriously dif cult with biocontrol to obtain good, consistent data from small-scale experiments. Such data is best obtained from large, long-term trials, but to do this it is necessary to have large-scale production systems, preferably with industrial support. Most production com- panies, however, need to see good ef cacy data from eld trials before they will invest in new products. BioNem Ltd attempts to ll this gap between research and commer- cialisation by selecting effective agents (fungal parasites), developing suitable production systems, and conducting realistic eld tests. The two fungi I am concentrating on are Paecilomyces lilacinus and Verticillium chlamydospo- rium . 086 The commercialisation of Paecilomyces lilacinus as an agent for the control of plant-parasitic nematodes Diane N EETHLING Biological Control Products SA (Pty) Ltd, P.O. Box 1561, Pinetown 3600, South Africa Paecilomyces lilacinus is one of a number of fungi with nematophagous properties that have been examined over the past two decades for potential use as agents for the control of plant pathogenic nematodes in agriculture. While showing promise, their commercialisation has in the past been constrained by eld results which have not delivered suf cient promise to attract commercial atten- tion, as well as a certain lack of appreciation by farm- ing communities at large of the economic signi cance of nematode infestation. The South African company, Bio- logical Control Products (BCP) was established in 1995 with funding secured from private investors together with a substantial grant from the South African government. BCP’s prime objective was to conduct the necessary ap- plied research in areas of product formulation, eld ap- plication and solid substrate manufacture which would lead to acceptance by the agricultural community and reg- ulatory authorities of Paecilomyces lilacinus as an eco- nomically justi able addition to strategies for the man- agement of plant-parasitic nematodes. While the develop- ment of the manufacturing process and product formu- lation was largely conducted in-house, the research in- stitutes attached to the Department of Agriculture were commissioned to assist with ef cacy trials. BCP now has registration for the use of this biological agent sold un- der the brand name Pl Plus, for the control of nematodes in bananas, papinos, tomatoes, tobacco and citrus. Fur- ther trials are in progress on other crops. A solid substrate manufacturing plant capable of processing up to 50 t per year has been in operation since 1997 and local farmers currently use Pl Plus in integrated crop protection pro- grammes. 087 In vitro culture of Pasteuria penetrans Thomas E. H EWLETT 1 ; ¤ , John F. G ERBER 2 , Kelly S. S MITH 1 and James H. W HITE 1 1 Entomos LLC, 4445 SW 35 th Terr., Suite 310, Gainesville, FL 32608, USA 2 CDG Laboratories, Inc., Gainesville, FL, USA ¤ tom@entomos.com 152 Nematology</p>
<p>Symposium abstracts Pasteuria penetrans has been acknowledged worldwide as an effective biological control agent of plant parasitic nematodes. The inability to mass-produce this fastidious bacterium in vitro has been the barrier to making P. penetrans a marketable product. Enterobacter cloacae , a ubiquitous soil bacterium, has been found in close association with the cuticle of Meloidogyne arenaria females extracted from tomato roots. Co-cultures of E. cloacae and P. penetrans in simple nutrient broth have produced viable P. penetrans endospores. Filtrates from E. cloacae grown on simple nutrient broth are suitable culture media for both vegetative growth and sporulation of P. penetrans , producing viable, infective endospores. In vitro culture and therefore mass production of P. penetrans is now possible. 088 Development of multi-component transplant mixes for plant growth-promotion and disease suppression Nancy K OKALIS -B URELLE USDA, ARS, U.S. Horticultural Research Lab, Fort Pierce, FL 34945, USA nburelle@saa.ars.usda.gov Research was undertaken to develop a biologically-based product that, when added to transplant mixes, would en- hance plant growth, increase yield, and provide protec- tion against pathogens. Studies at Auburn University in cooperation with Gustafson LLC tested organic compo- nents and plant growth-promoting rhizobacteria (PGPR) for effects on tomato growth and nematode viability. Or- ganic components and PGPR were combined and eval- uated. Gustafson LLC and USDA, ARS then entered into a Cooperative Research and Development Agreement (CRADA) for eld-testing in Florida, where combina- tions of amended transplants and methyl bromide alterna- tive soil treatments were evaluated. Signi cant increases in tomato and pepper growth, vigor, and transplant sur- vival occurred with formulations of PGPR. One formula- tion reduced root-knot nematode galling and several im- proved pepper root condition. Four PGPR treatments re- duced angular leaf spot lesions caused by Pseudomonas syringae pv. lachrymans, and gummy stem blight, caused by Didymella bryoniae, on watermelon. One PGPR treat- ment reduced root-knot nematode disease severity on muskmelon. The effects of bare root, plug, and PGPR amended plug transplants on growth and yield of straw- berry showed that PGPR amended plugs had highest yields, and bare root transplants had lowest yields. This cooperative research resulted in a commercial product, BioYield ™ , for use on transplanted crops. 089 Nematode movement through soil: simple responses in a complex environment A. Forest R OBINSON USDA-ARS, 2765 F&B Rd, College Station, TX 77845, USA In theory, similar responses to simple cues can guide eco- logically different nematodes through the soil in com- pletely different ways, when the unique characteristics of gas and solute diffusion, water movement, and tempera- ture uctuation in soil are considered in relation to sub- tle differences in response thresholds, rates of locomo- tion, and sensory adaptation. Validation of models of ne- matode movement within the diurnally uctuating, verti- cal temperature gradients of soil con rmed that two root- parasitic species that respond similarly under static con- ditions on agar move in opposite directions in thermody- namically natural soil. Experiments on attraction to CO 2 in soil showed that gradients inducing maximal nematode accumulation at a point source are achieved at optimal soil moisture for nematode movement, are not generated in saturated soil, and can be sustained for 24 h in soil with a total gas volume that would not induce attraction on agar in most assays. Evidence from entomopathogenic and nematophagousnematodes suggests additionalchem- ical stimuli modulate responses to CO 2 as observed for insects. Future progress will be accelerated by integration of molecular, anatomical, and physiologicaldata from di- verse nematodes, direct comparisons within soil, better conceptual preparation, and improved techniques to mea- sure and simulate the conditionsand stimulus gradients of soil. 090 Sensory responses of plant-parasitic nematodes to semiochemicals Ekaterini R IGA Washington State University, IAREC, 24106 N. Bunn Rd., Prosser, WA 99350, USA riga@wsu.edu The understanding of nematode semiochemicals has im- proved in recent years due to incorporation of novel tech- niques to study nematode behaviour. Extracellular elec- trophysiological recordings from the cephalic region of plant-parasitic nematodes in conjunctionwith behavioural bioassays have revealed that chemoreception is essential Vol. 4(2), 2002 153</p>
<p>Sensory response and behaviour (89-92) and Vertebrate parasitic nematodes (93-96) for nematode survival. The function of the amphids as a main chemoreception organ has been af rmed in all nematode behavioural studies. Principal semiochemicals that elicit nematode responses are plant host exudates, food stimulants, food deterrents, and homospeci c sex pheromones. Several amino acids and plant root diffusates elicited positive responses from plant nematodes. In addi- tion, sensory adaptation and chemical isomer speci city have been demonstrated. Recordings from the cephalic region of a potato cyst nematode, Globodera rostochien- sis , veri ed the species-speci c nature of sex pheromones. Biological activity associated with G. rostochiensis and Heterodera schachtii sex pheromones has been linked to a speci c HPLC-derived fraction, and although the sex pheromones have not yet been identi ed, their physical properties have been reported. Sensory physiology is a new and promising eld in nematology that will lead us to a better understanding of nematode biology and will provide a means to control nematodes by interfering with their sensory perception. 091 Neuropeptide signalling systems in parasitic nematodes and their potential as novel control targets Aaron G. M AULE 1 ; ¤ , Nikki J. M ARKS 1 , Angela M OUSLEY 1 , Michael K IMBER 1 , Colin F. F LEMING 2 ; 3 , David W. H ALTON 1 , Timothy G. G EARY 4 and David P. T HOMPSON 4 1 Parasitology Research Group, School of Biology and Biochemistry, Belfast BT9 7BL, UK 2 Applied Plant Science, Queen’s University Belfast, Belfast BT9 7BL, UK 3 Department of Agriculture and Rural Development for Northern Ireland, Newforge Lane, Belfast, BT9 5PX, UK 4 Pharmacia Animal Health, Kalamazoo, MI 49001, USA ¤ a.maule@qub.ac.uk The diversity of neuropeptide signalling molecules in nematodes is as great as that known for any organism. By far the largest and most multifaceted nematode neuropeptide family is the FMRFamide-related peptides (FaRPs). In Caenorhabditis elegans , this family comprises 60 distinct peptides that are encoded on 22 genes (designated p -genes) and available evidence indicates that this complexity is mirrored in plant and animal parasitic nematodes. Neuropeptides are known to be expressed in all neuronal subtypes and to have potent and wide-ranging effects on motility, alimentation, reproductive function and sensory perception. Although the effects of FaRPs are widespread in nematodes, individual p -genes have restricted expression patterns indicating speci c roles for encoded peptides. Sequence data reveal that a signi cant number of FaRPs are structurally homologousacross a broad range of nematode species; a similar pattern of functional homology remains to be established. While information on FaRP receptors is limited, physiological data suggest that the diversity in FaRP structure is not re ected by endogenous FaRP receptors. The FaRP-signalling system likely harbours numerous potential targets for novel control measures. However, the selection and exploitation of these is made dif cult by the complexity inherent within the FaRP signalling system and the potential for functional redundancy. 092 Chemoreceptor genes: what can we learn from C. elegans and how can we apply this information to studies on other nematodes? Ann M. B URNELL ¤ and Damien M. O’H ALLORAN Institute of Bioengineering and Agroecology and Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland ¤ ann.burnell@may.ie Soil dwelling nematodes encounter many types of volatile and water-soluble molecules in their environment. For free-living nematodes like C. elegans , successful foraging depends on the ability to detect a gradient in one odorant while ignoring extraneous odours. The infectious stages of plant and animal parasitic nematodes also rely on chemoreception as their primary host nding cue. Using a combination of genetic, molecular and bioinformatic approaches chemoreceptor genes have been identi ed in C. elegans . These C. elegans chemoreceptor genes encode seven-transmembrane G-protein coupled receptors (GPCRs) and comprise the largest gene family in this nematode. GPCRs are also involved in olfactory signal transduction across a broad spectrum of animals including insects, crustaceans, sh and mammals, but the C. elegans (and Drosophila ) chemoreceptorgenes have no sequence homology to vertebrate GPCR odour receptor genes and they also differ from vertebrate odour receptor genes in their genomic structure. In this presentation we will provide overview of the genomic structure and diversity of odorant and chemoreceptor gene families in vertebrates and invertebrates and we describe our attempts, using homology-based approaches, to isolate chemoreceptor genes in the entomopathogenic nematode Heterorhabditis bacteriophora . 154 Nematology</p>
<p>Symposium abstracts 093 Ecological aspects of small mammal nematode infections S. M AS -C OMA Departamento de Parasitología, Facultad de Farmacia, Universidad de Valencia, Av. Vicent Andrés Estellés s/n, 46100 Burjassot-Valencia, Spain S.Mas.Coma@uv.es Nematodes have many adaptation and colonisation capacities. This explains how they were successful in colonising animal hosts from evolutionary lines of free-living nematode groups. Recent results on 18S rRNA gene sequencing and corresponding phylogenetic analyses show how the adaptation of a parasitic way of life was acquired by different free-living nematode groups independently. These analyses also suggest that phylogeny inferred from DNA sequences does not always agree with the present systematic groupings within the Secernentea. Moreover, studies carried out on nematode parasites of small mammals (rodents and insectivores) on islands in the last 20 years show that the resulting evidence does not support mathematical models which prove that nematode species following a one-host life cycle are more capable to colonise new environments and expand. Small mammal nematodes are excellent models for ecological and evolutionary studies because they include many nematode groups presenting very different types of life cycle patterns, from monoxenous to heteroxenous life cycles. Monoxenous nematode species infecting rodents and insectivores comprise ageohelminths, pseudogeohelminths and geohelminths. Heteroxenous nematodes of small mammals include species transmitted by intermediate hosts pertaining to different invertebrate and vertebrate groups. This wide biological spectrum becomes a very useful tool for ecological and short-term evolutionary studies. 094 Studies on nematodes of wild carnivores Carlos F ELIU , Alexis R IBAS and Juan Carlos C ASANOVA Laboratori de Parasitologia, Facultat de Farmàcia, Universitat de Barcelona, Avda Diagonal s/n. 08028 Barcelona The Iberian carnivores constitute a group of hosts where the diversity of its nematodes is not very high (45 species) compared with other mammal groups. From a faunistic point of view it is signi cant that: i ) two endemic species are restricted to the Iberian Peninsula ( Ancylostoma martinezi in Genetta genetta (common genet); Vigisospirura potekhina hugoti in Meles meles (badger); ii ) the high richness in nematodes species in Vulpes vulpes (fox) (16 species), Martes foina (stone marten) (14 species) and Genetta genetta (12 species), probably as a the result of a wide range of distribution of these hosts as habitat generalists. From an ecological point of view: i ) there is an high ethologic incidence of the host to the nematode fauna; this is specially notable in the case of Mustelidae, which include hosts with aquatic, amphibian or terrestrial behaviours;the last group presents the highest number of nematode species; ii ) the diet of the hosts is another important determining factor; morever from indirect life cycle nematodes, it is possible to know with high precision which taxa are prey of these hosts. The speci city of reported nematodes in Iberian Carnivora also gives information about the phylogeny of the host. 095 Nematode parasitic fauna in Canary Island vertebrates Basilio V ALLADARES Departamento de Parasitología, Facultad de Farmacia, Universidad de La Laguna, Spain bvallada@ull.es In the Department of Parasitology in La Laguna University, many faunistic, ecological and biological studies on parasitic helminths in vertebrates have been undertaken over several years. Despite this, nematode studies have only been carried out on Canis familiaris and in the species which can cause zoonosis in man, Toxocara canis and Diro laria immitis . The in uence of the Canary Island microclimate on their distribution and the insularity effect were also studied. Since 1999, parasitic helminths in Canary Island birds have been studied and the nematofauna is the best known group at the moment. The bird species (105) analysed include Alectoris Barbara , Larus cachinnans , Columba livia , Fulica atra and Chalmydotis undulata . The nematodes obtained were studied under optical microscopy by clearing with Amman lactophenol. In order to study the samples using scanning electronic microscopy (SEM), Mercer and Birbeck (1979), Ba and Marchand (1994) and Miquel and Marchand (1998) techniques were used. The helminth species identi ed in the different birds under study were as follows: in Alectoris Barbara : Aonchoteca caudin ata , Ascaridia galli ( rst report in this host), Baruscapillaria obsignata , Eucoleus annulatus Vol. 4(2), 2002 155</p>
<p>New technologies and chemicals for control of plant pathogenic nematodes (97-100) and Heterakis gallinarum : in Columba livia : Aonchoteca sp., Tetrameres ssipina , Synhimantus ( Dispharynx ) spiralis and Ascaridia columbae , and in Fulica atra , Capillaria sp. were found and in Larus cachinnans, Cosmocephalus sp. The effect of insularity on the parasites is studied. 096 Some problems related to the control of nematode infections in domestic ruminants Francisco A. R OJO -V ÁZQUEZ 1 , Antonio R. M ARTÍNEZ -F ERNÁNDEZ 2 , M.A. Á LVAREZ -S ÁNCHEZ 1 , J. P ÉREZ -G ARCÍA 1 and R.C. M AINAR -J AIME 1 1 Dpto de Sanidad Animal, Universidad de León, Spain 2 Dpto de Parasitología, UCM, Madrid, Spain Gastrointestinal nematode infections in small ruminants are of great importance in animal husbandry worldwide. The control is based on the knowledge of the epidemiol- ogy, the detection of nematode eggs in faeces on a rep- resentative number of animals from the ock, the use of anthelmintic drugs and management practices. However, faecal egg counts are highly variable and must be done on a large number of animals in order to get accurate esti- mations of the parasite burdens within the ock. On the other hand, the routine and inadequate application of an- thelmintics is another problem, due to the development of anthelmintic resistance (AR). In Spain, some recent re- ports on AR in small ruminants shows a ock prevalence of 21%. Although benzimidazoles(BZ) has been the most used anthelmintic during the last decade, BZ-resistance is still low. However, there is a high level of AR against im- idazothiazoles. Two factors were signi cantly associated with resistance or suspicion of resistance: breed and an- thelmintic ef cacy according to the farmer. Foreign and crossbreed ocks seemed to be more prone to present AR. Higher probabilities of AR seemed to be related to ocks that used mostly private pastures or to those that bought replacement animals. 097 The cost of licensing and labeling a methyl bromide alternative Robin N. H UETTEL 105 Comer Hall, College of Agriculture, Auburn University, Auburn, AL 36849, USA huettro@auburn.edu There are many time consuming and costly processes involved with taking a new pesticide to market. While many researchers are searching for drop-in replacements for methyl bromide (MeBr), developing a new formulation or improving on an old one is just the beginning of the process. Ef cacy data and eld testing under one’s own research programme might indicate promising results but the developer needs to be ready for a 3-4 year process which can cost in excess of US $12 m. It is important that no steps or agencies are overlooked in the long road to a marketable product. There are many considerations, such as venture capital, the patenting process for both US and foreign proprietary rights, support for minor use pesticide eld testing and addressing all steps required by the US Environmental Protection Agency. This presentation will cover what it takes to get a MeBr alternative to market in the US and beyond. 098 Soil fumigation: new uses for old chemicals and new compounds R. R ODRIGUEZ -K ABANA Department of Entomology & Plant Pathology, Auburn University, Auburn, AL 36849, USA rrodrigu@acesag.auburn.edu The imminent removal of methyl bromide (MBR) as a soil fumigant has stimulated a world-wide search for al- ternative treatments. This decade-long effort identi ed the old fumigants: 1,3-dichloropropene (1,3-D), chloropicrin, methyl isothiocyanate (MITC), and compounds that gen- erate MITC, as the only materials available at present for development of preparations capable of substituting MBR in soil fumigation. New formulations and applica- tion technologies have been devised to increase the ef - cacy and practicality of these very old chemicals as MBR alternatives.Other compoundsshowing promise for future development as MBR substitutes are: inorganic azides, propyleneoxide, methyl iodide and other iodinated hydro- carbons. Several naturally occurring ‘biofumigant’ com- pounds ( e.g ., citral, fufural, various mustard oils such as allyl isothiocyanate) are also being explored as MBR al- ternatives. The main dif culty in nding MBR substitutes for soil fumigation resides in the need to develop econom- ical soil treatments that are safe, environmentally accept- able and effective, not only against plant-pathogenic ne- matodes but also weeds, and other soil-borne pathogens and pests. 156 Nematology</p>
<p>Symposium abstracts 099 New technologies for challenging situations – perennial and nursery crops in California Sally S CHNEIDER USDA ARS SJVASC, 9611 S. Riverbend Ave, Parlier, CA 93648, USA sschneider@fresno.ars.usda.gov Nursery crops that are grown in California for commercial plantings are required to be free of plant-parasitic nematodes. Nursery certi cation can be accomplished by extensive sampling or by use of an approved soil treatment. Approved treatments (materials and rates) vary with soil type, moisture, temperature, and cropping history of the eld and show ef cacy to a depth of 150 cm. Historically, the most commonly used material was methyl bromide. Prior to planting the certi ed trees and vines, growers often fumigated with methyl bromide to prevent replant disorder in their orchards and vineyards. Combinations of new and existing technologies, novel application methods, and registered and experimental materials are being tested for use in nursery and perennial replant situations. Global positioning satellite systems can be used to implement management strategies into areas selected for optimal performance based on the spatial variability of soil conditions. Drip irrigation technologies can be used to deliver emulsi able formulations throughout the soil pro le to the depth needed – especially for materials that do not move as readily as methyl bromide. Currently registered and experimental materials can be re-evaluated in light of these new technologies. Rescue strategies are necessary for situations where the management strategy has failed. 100 Basic strategies for defensive response of plants against nematodes J.G. L UIS Instituto Universitario de Bio-Orgánica ‘Antonio González’, Universidad de La Laguna, Avda, Francisco Sánchez, 2, 38206 La Laguna, Tenerife, Canary Islands, Spain In the last few years, our Ecological Chemistry research group has been engaged in molecular level studies on the host-plant interactions between banana cultivars and the pathogens: Fusarium oxysporum , Mycosphaerella jensis and Radopholus similis . Several susceptible banana cultivars elicit a defence response to attack by the pathogens characterised by de novo production of a new type of phytoalexins, hitherto undescribed. The pathogen resistant banana hybrid SH-3481 (from FHIA), produces large amounts of these phytoalexins and phytoanticipins (constitutive natural antibiotics), suggesting that this new type of phytoalexins plays an important role in the resistance mechanisms of banana plants against fungal and nematode diseases. The signi cance of these ndings will be discussed as they may open the way to development of new sustainable agricultural methodologies to manage plant diseases. 101 Quest for resistance to the peanut pod nematode A.H. M CDONAL D , H. F OURIE ¤ and S. S TEENKAMP ARC-Grain Crops Institute, Private Bag X1251, Potchefstroom 2520, Republic of South Africa ¤ driekie@igg2.agric.za Since its discovery in 1987, the peanut pod nematode Ditylenchus africanus is regarded as one of the econom- ically most important pests of peanut in South Africa. The nematode is omnipresent in peanut production areas in this country and its most signi cant impact is on ker- nel and seed downgrading, which causes serious losses in income for the producers. This, in turn, has a detri- mental effect on net national peanut production.Although a signi cant number of scienti c publications have been published over the past few years, the occurrence of the peanut pod nematode seems to be restricted to South Africa. Screening of local peanut germplasm, selected elite breeding lines and hybrids provided at best a par- tial level of resistance to D. africanus . This partial resis- tance, however, is overcome at high nematode infestation levels, which is common in peanut elds, given the nema- tode high reproductive potential. The local genetic vari- ation in peanut breeding material is small. Most popular hybrids are Spanish or Virginia ‘bunch’ types, with a few ‘runners’ still produced in remote areas. The uniqueness of this nematode problem and the narrow genetic back- ground of available peanut germplasm present a challenge for the selection and application of resistance as a sustain- able strategy to manage D. africanus in peanut. 102 Resistance to root-lesion nematodes in Coffea canephora Luc V ILLAIN 1 ; ¤ , Francisco A NZUETO 2 and Jean-Louis S ARAH 3 Vol. 4(2), 2002 157</p>
<p>Resistance breeding against non sedentary nematodes (101-103) and Food webs (104-106) 1 CIRAD TA 80/PS3 Avenue Agropolis, 34398 Montpellier Cedex 5 France 2 ANACAFE, 5a Calle 00-50, Zona 14, Guatemala Ciudad, Guatemala 3 CIRAD TA 40/02 Avenue Agropolis, 34398 Montpellier Cedex 5 France ¤ luc.villain@cirad.fr Root-lesion nematodes ( Pratylenchus spp.) are widely distributed in coffee plantations worldwide. In Central America, many of them are highly pathogenic on Coffea arabica causing important economic damage. The poor ef ciency of nematicide treatments to control Pratylenchus spp. was demonstrated in Guatemala. In this country, C. canephora was used as a rootstock for 30 years empirically. Analysis pointed out the low level of root-lesion nematodes in the elds where this grafting technique was used. Comparative studies of penetration dynamics and reproductive tness on coffee seedlings as well as eld trials demonstrated the existence of pre- and post infection factors of partial resistance to Pratylenchus spp. in some C. canephora genotypes. Complementary histological studies of roots showed no noticeable structural differences between C. arabica and C. canephora . On the other hand, the presence of high amounts of polyphenols was observed in the roots of a C. canephora resistant genotype even before nematode penetration, suggesting the existence of constitutive factors of resistance. Sources and mechanisms of resistance must be investigated more exhaustively among C. canephora germplasm. Grafting onto C. canephora constitutes today the best alternative to nematicide treatments for controlling phytoparasitic nematode communities in C. arabica coffee crop, as some C. canephora genotypes also show resistance to highly pathogenic root-knot nematodes ( Meloidogyne spp.). 103 In vitro screening as an early rapid and reliable tool to detect resistance against migratory endoparasitic nematodes Annemie E LSEN Laboratory of Tropical Crop Improvement, K.U.Leuven, Kasteelpark Arenberg 13, 3001, Leuven, Belgium annemie.elsen@agr.kuleuven.ac.be Growing nematode-resistant crop varieties is considered as an effective and sustainable method for nematode management. Identi cation and selection of resistant varieties often occurs in the eld, but eld testing is time consuming, especially with large-sized plants. Therefore, early and rapid screening of plant material for detection of nematode resistance is desirable. It allows a rapid selection at the very early plant stage of potentially interesting candidates. An in vitro screening method allows the elimination of susceptible germplasm, even earlier compared to early screening in climatic chambers or glass-/screenhouses. However, the nal selection must still be performed in the eld, but massive elimination of clearly non-resistant plant material would considerably reduce the size of such eld screening. To date, the use of in vitro culturing techniques has been well demonstrated as a rapid and reliable tool for determining reproductive capabilities of plant-parasitic nematodes on known hosts, new hosts and resistant varieties. In vitro screening of varieties for resistance to plant-parasitic nematodes was rst demonstrated for root- knot nematodes, Meloidogyne spp., using excised tomato roots. Nowadays, root-explant cultures of many different plants have been used for evaluating resistance to both sedentary and migratory endoparasitic nematodes. In vitro screening procedures were successfully developed for Musa , allowing selection of constitutiveresistance against the root-lesion nematode, Radopholus similis . 104 Structure and function of food webs Bryan S. G RIFFITHS 1 ; ¤ , Wim VAN DER P UTTEN 2 and Peter C. DE R UITER 3 1 Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK 2 Netherlands Institute of Ecology, Centre for Terrestrial Ecology, P.O. Box 40, NL-6666 ZG Heteren, NL 3 Department of Environmental Sciences, University Utrecht, P.O. Box 80115, 3508 TC Utrecht, NL ¤ bgriff@scri.sari.ac.uk Several soil food webs have been thoroughly described and the importance of nematodes is evident from their representation at different trophic links – as plant-feeders, secondary detritivores, predators and omnivores. Car- bon ow models have shown the importance of several pathways, including those through bacterial- and fungal- feeders to predaceous nematodes, and from plant roots through plant-feeders. The herbivory pathway has been observed experimentally by following a pulse of 13 C, ap- plied above-ground, through the soil community. Novel observations are also emerging on the effects of root- feeding fauna on above-ground food webs. Disturbance of food web groups causes a loss in stability, reduced bio- diversity and changes in soil processes. Consideration of 158 Nematology</p>
<p>Symposium abstracts biodiversity in food web models will allow exploration of biodiversity-productivity and biodiversity-stability re- lationships. Modelling interactions according to func- tion rather than species reveal interesting interactions in above-ground food webs. Current soil food web models group organisms by function and taxa, but for improved understanding of the system information on broader func- tional groups may be more appropriate. Current initiatives and developments in food web research and theory high- light the importance of soil food webs in biosphere func- tion and are providing insights into the preservation, con- servation and management of soil systems. 105 Carbon and energy sources for nematodes Tom M OENS 1 ; ¤ , Gregor W. Y EATES 2 and Paul D E L EY 3 1 Biology Department, Ghent University, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium 2 Landcare Research, Private Bag 11-052, Palmerston North, New Zealand 3 Department of Nematology, University of California, Riverside, California, USA ¤ tom.moens@rug.ac.be Nematode species diversity, even at small spatial scales, provides an intriguing system for studies on resource par- titioning and on links between biodiversity and ecosys- tem function. The ubiquity and abundance of nema- todes in soils and aquatic sediments interest ecologists seeking models for uxes of carbon, nitrogen, phos- phorus etc . However, the complete spectrum of roles and the quantitative importance of nematodes in soils and aquatic sediments remain poorly documented. Food sources of nematodes are usually inferred from buccal morphology but there are many unresolved questions on food sources and feeding rates. Current functional guild classi cations are useful but in some cases, in- cluding nematodes with minute buccal cavities and ty- lenchids with delicate spears, food sources are uncer- tain. We discuss whether, and how, a limited diversity of functional types can be reconciled with great species diversity and present a laboratory approach for studying functional redundancy among bacterivorous nematode species. To relate laboratory-derived feeding rates to population growth rates under natural conditions, we address the effects of external in uences on nematode activity in soils, including texture, aeration, temperature and moisture. 106 Decomposition pathways and successional changes Liliane R UESS 1 ; ¤ and Howard F ERRIS 2 1 Institute of Zoology, TU Darmstadt, Schnittspahnstr. 3, 64287 Darmstadt, Germany 2 Department of Nematology, University of California, Davis, CA 95616, USA ¤ ruess@bio.tu.darmstadt.de In soils, energy and nutrient pathways are primarily me- diated by bacteria or fungi. Bacteria-dominated systems rapidly transfer nutrients, directly and via consumers, to plants. In contrast, fungal-based decomposition channels are slower; they are driven by more complex organic re- sources. There are strong linkages between nematodes and their fungal or bacterial food sources. On one hand, consumer organisms affect rates of energy and nutrient release from their prey; on the other hand, they may regu- late the prey biomass. The nature and abundance of avail- able resources can be monitored by faunal analysis of fungal- and bacterial-feeding nematodes (f/b ratio, chan- nel index). The resources change constitutively with time. Readily decomposable portions are rapidly consumed by bacteria and their predators so that the recalcitrant frac- tion becomes proportionally greater. That change is mir- rored by corresponding increase in fungal decomposition and re ected in the nematode fauna. We discuss the re- lationship of nematode trophic structure with the nature of the incoming organic material and the prevailing state of the physical environment. For example, decomposition pathways of natural forests are predominantly fungal and those of agricultural systems are bacterial. We discuss the signi cance of the pathways in relation to the structure and functions of the entire soil food web. Vol. 4(2), 2002 159</p>
<p>Detection and diagnostics (107-122) 107 Immuno-magnetic capture (IMC): a novel approach to nematode diagnostics Qing C HEN 1 ; ¤ , Lee R OBERTSON 2 , Rosane H. C URTIS 3 , John T. J ONES 1 and Derek J.F. B ROWN 1 1 Plant-Pathogen Interactions Programme, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK 2 Universidad de Castilla-La Mancha, Facultad de Ciencias del Medio Ambiente, Edi cio Sabatini, Laboratorio 0.8, E-45071 Toledo, Spain 3 Nematode Interactions Unit, IACR Rothamsted, Harpenden, Herts AL5 2JQ, UK ¤ qchen@scri.sari.ac.uk Simple, rapid and reliable diagnostic techniques are important for identi cation and quanti cation of plant- parasitic nematodes. Current diagnostic methods have limitations for eld sample detection. ELISA diagnosis is less sensitive than PCR and the sensitivity of PCR based methods is strongly affected by inhibitors from soil. IMC offers several advantages which overcome these drawbacks. In IMC an antibody which recognises the surface of target nematodes is incubated with a nematode suspension extracted from a eld sample. Then, secondary-antibodycoated magnetic beads are added and a magnet is used to capture target nematodes while other nematodes are discarded. We have used IMC to detect Meloidogyne arenaria and a virus-vector nematode Xiphenema americanum. Eighty and 60% of target nematodes, respectively, were recovered from mixed soil samples. These results show that IMC is an effective method of detecting speci c nematodes in mixed soil samples. IMC converts eld nematode samples to lab- friendly samples, containing highly concentrated target nematodes suitable for further serological or molecular techniques, such as ELISA, PCR or Taqman , which can be used to detect and quantify speci c nematodes or viruses. We are currently examining the potential commercial applications of combining IMC with PCR- based diagnostics for routine detection of virus vector nematodes. 108 Detection of GFLV in Xiphinema index with DNA-based uorescent probes Mariella F INETTI -S IALER 1 and Aurelio C IANCIO 2 ; ¤ 1 Dipartimento di Protezione delle Piante, Università degli Studi, Bari, Italy 2 Istituto per la Protezione delle Piante, Consiglio Nazionale delle Ricerche, Via Amendola 165/A, 70126 Bari, Italy ¤ ciancio@area.ba.cnr.it A PCR based method was applied to the detection of grapevine fanleaf virus (GFLV). The virus was ampli ed from specimens of its vector Xiphinema index , collected in a grapevine orchard at Palagiano, Italy. The detection was carried out with a real-time uorescent RT-PCR assay. A set of primers was designed for the GFLV RNA- 2 ampli cation. A 2500 bp fragment was ampli ed by RT-PCR, from X. index adults and juveniles, cloned and sequenced. We compared the obtained GFLV sequences with those available in GenBank and two regions were selected for virus detection and/or strain identi cation. A uorescent Scorpion probe was designed to amplify a 100 bp fragment within the conserved region of the cp gene. A 21 bp conserved motif at position 2855 was used as probe target. An additional region with strain-speci c nucleotide variations at position 2502 was used to discriminate between the Palagiano and other GFLV strains. Speci c oligos, constructed on the basis of GenBank sequences AF304015 and X16907, were used as controls. Furthermore, a set of three strain-speci c molecular beacons was designed on this region and used with the ampli ed DNA or oligos. The successful detection of the probe targets was shown by uorescent signals emitted during ampli cation or under UV excitation. The Scorpion probe proved to be useful in virus detection. Due to their single-base mismatch sensitivity, the molecular beacons appeared suitable for speci c strain recognition. The potential of these technologiesin the study of transmission and vector epidemiology are brie y discussed. 109 Advances in applied nematode research in South Africa after introduction of the SCAR-PCR technique for nematode identi cation Hendrika F OURIE 1 ; ¤ , Caroline Z IJLSTRA 2 , Alexander Henrique M C D ONALD 1 and Gertruida Anna V ENTER 1 1 ARC-Grain Crops Institute, Private Bag X1251, Potchefstroom, 2520, South Africa 2 Plant Research International, P.O. Box 16, 6700 AA Wageningen, The Netherlands ¤ driekie@igg2.aric.za The availability of well-de ned nematode populations is essential for host plant resistance screening, breeding and crop rotation purposes. Identi cation of monocultureroot- knot nematode species occurring in South African soils 160 Nematology</p>
<p>Poster sessions and differentiation between species in mixed populations were done by means of the sequence characterised ampli ed region – polymerase chain reaction (SCAR- PCR) technique. Meloidogyne fallax , M. chitwoodi , M. javanica , M. incognita , M. arenaria and M. hapla were identi ed from various crops. Multiplex internal transcribed spacer (ITS)-PCR ampli ed a fragment in an unknown root-knot nematode species for which no SCAR-marker is presently available. This technique enabled the identi cation of M. fallax , a quarantine organism in Europe, as a new record for South Africa where presence at two localities was established. Resulting from this study, the geographical distribution of M. chitwoodi was expanded from two to ve known localities in this country. Root-knot nematode species composition of eld and glasshouse isolates can be monitored frequently using the SCAR-PCR technique, which allows for routine analyses of root-knot nematode species used in research programmes. 110 Detection and eradication of plant-parasitic nematodes in imported germplasm in Brazil V. G ONZAGA 1 ; ¤ , R.C.V. T ENENTE 1 and J.K.A. M ATOS 2 1 EMBRAPA, Genetic Resources and Biotechnology, P.O. Box 2372 (70849-970) Brasilia, DF, Brazil 2 Universidade de Brasília, P.O. Box 4508 (70910-970) Brasilia, DF, Brazil ¤ vgonzaga@cenargen.embrapa.br The Laboratory of Plant Quarantine of Embrapa Ge- netic Resources and Biotechnology makes phytosanitary analyses of most of the plant germplasm introduced in Brazil. During 2001, plant-parasitic nematodes were de- tected associated with 1738 germplasm accessions com- ing from several countries. The material infected with nematodes were corn, wheat, rice, soybean, oats, melon, sesame, cocoa, coffee, orchid, neen, clover and lespedeza. Those materials were introducedfrom the following coun- tries: France, Mexico, USA, Colombia, Japan, Argentina, Venezuela, Trinidad-Tobago, Guatemala, Dominican Re- public, Philippines, Spain and Holland. The techniques used for extraction and detection of the nematodes were Baermann funnel, tray technique, sieving and blending and cyst detection by Fenwick can. The plant-parasitic ne- matodes detected were Ditylenchus dipsaci , Ditylenchus parvus , Ditylenchus sp., Aphelenchoides besseyi , Aphe- lenchoides sp., Aphelenchus avenae , Aphelenchus sp., Helicotylenchus sp. and Hoplolaimidae. The accessions were submitted to dry and humid thermal treatments and to chemical treatments for eradication of the nema- todes, which was successful in all but a few accessions. With these phytosanitarymethods the Laboratory of Plant Quarantine of Embrapa Genetic Resources and Biotech- nology collaboratesactively to reduce the risk of introduc- tion of new plant-parasitic nematodes species in Brazil. 111 Professional automated extracting apparatus for free-living nematodes Gerard H ENDRICKX Crop Protection Department, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium g.hendrickx@clo.fgov.be Nematode extraction by elutriation and subsequent separation on a cotton wool lter is labour-intensive,time consuming, and inef cient. Full automation is dif cult. Extraction based on centrifugal otation in swinging buckets is faster and more ef cient but does not allow for extraction of large volumes and is still dif cult to automate. A prototype of a fully automated extraction apparatus was built using a zonal centrifuge. With this prototype the sample volume was limited to 100 cm 3 soil (10 cm 3 extracted); subsequently, a version processing 200 cm 3 (100 cm 3 extracted) was constructed. Besides previous modi cations, changes were made aiming at an easier and safer operation by using a conveyor-belt, a pneumatic drive, and a fool-proof design. The apparatus is commercial and can be used to extract other plant pathogens from soil. 112 Magnetic separation as a tool in a sample preparation procedure for direct detection and quanti cation of trichodorid nematodes Rodanthi C. H OLEVA 1 ; ¤ , Qing C HEN 1 , Rosane C URTIS 2 , Roy N EILSON 1 , John J ONES 1 , Vivian B LOK 1 and Derek J.F. B ROWN 1 1 Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK 2 IACR Rothamsted, Harpenden, Herts AL5 2JQ, England, UK ¤ rholev@scri.sari.ac.uk The detection of trichodorid nematodes in soil samples is dif cult as conventional methods are laborious, time-consuming and rely on specialist knowledge of morphologicalcharacteristics of the species. To overcome these dif culties the potential of magnetic separation for recovering target nematodes from soil populations Vol. 4(2), 2002 161</p>
<p>Detection and diagnostics (107-122) of nematodes was investigated. Lectins and polyclonal antiserum that bound speci cally and reproducibly to the overall surface of Paratrichodorus anemones were identi ed and bound to monodisperse superparamagnetic particles (Dynabeads) to capture target nematodes from test suspensions. In recovery experiments, while both types of probe isolated nematodes from suspension, antibody-coated beads recovered them more ef ciently than beads coated with lectins. The results obtained suggest that the immuno-magnetic separation (IMS) technique has potential to provide a serological-based target nematode enrichment process. Furthermore, it represents a signi cant advance over current methods for recovering nematodes as it facilitates high throughput to screen large soil populations quickly and economically and, being technically simple, requires minimal labour input. 113 Development and evaluation of a uorogenic 5 0 nuclease PCR assay (TaqMan ™ ) for the detection and quanti cation of virus-vector trichodorid species Rodanthi C. H OLEVA ¤ , Vanessa Y OUNG , Konstantina B OUTSIKA , Mark P HILLIPS , Derek J.F. B ROWN , Roy N EILSON and Vivian B LOK Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK ¤ rholev@scri.sari.ac.uk Molecular detection of pests and pathogens relies on rapid and dependable methods for the identi cation and quanti cation of these organisms. Here, the development of a qualitative and quantitative diagnostic method for trichodorid nematodes based on TaqMan ™ chemistry is reported. Two independent primer/probe sets were designed targeting the 18S gene of the ribosomal cistron and producing an amplicon of 83bp for the virus-vector species, Paratrichodorus pachydermus and Trichodorus similis . The assay was applied to puri ed plasmid DNA containing clones of the 18S region from both nematode species, as well as to genomic DNA extracted from individual nematodes. Both primer/probe sets displayed high speci city as no cross-reaction was observed when tested with samples of two other trichodorid species. In experiments where dilutions of puri ed plasmid standards were used to test the analytic sensitivity, the TaqMan ™ assay detected nematode DNA to the femtogram level. Quanti cation of the target present in unknown samples was performed by comparison of the uorescence signals of the samples to those obtained from plasmid standard dilutions. Currently, simultaneous detection and quanti cation of the above trichodorid species is being evaluated. Our data con rm this to be a rapid, accurate and sensitive molecular diagnostic. 114 A method for estimating the ratio of Meloidogyne incognita to M. arenaria in mixed populations using PCR-RFLP Hideaki I WAHORI ¤ and Zen-ichi S ANO National Agricultural Research Center for Kyushu Okinawa Region, Nishigoushi, Kumamoto 861-1192, Japan ¤ iwahori@affrc.go.jp The most important root-knot nematodes in southwestern Japan are Meloidogyne incognita and M. arenaria . These two species are sometimes present in the same eld. We devised a method to estimate the ratio of M. incognita to M. arenaria in mixed populations using PCR-RFLP and image analysis. Various ratios of the two nematodes were prepared, then PCR-RFLP was performed using each ratio. Brightness of species-speci c RFLP bands for M. incognita and M. arenaria was quanti ed with image analysis using a computer program. The brightness of the M. incognita -speci c band to that of the M. arenaria band for each RFLP pattern was used as an estimate for the ratio of the two nematodes. A regression line was calculated from these values to estimate actual ratios. We applied this method successfully to eld samples. Attempts have also been made to apply this method to other nematode combinations, such as M. incognita and M. hapla or two different populations of Pratylenchus coffeae . 115 Detection of the reniform nematode in cotton using hyperspectral imagery A.T. K ELLEY 1 , G.W. L AWRENCE 1 , K.S. M C L EAN 2 and H.K. L EE 1 1 Department of Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA 2 Department of Entomology and Plant Pathology, Auburn University, Auburn University, USA FSKauburn@aol.com The reniform nematode ( Rotylenchulus reniformis Lin- ford and Oliveira, 1940) is one of the two most preva- lent nematodes on cotton ( Gossypium hirsutum L.) and is quickly spreading throughout the southeastern United States. This nematode inhibits cotton plant development resulting in reduced plant growth and sometimes plant 162 Nematology</p>
<p>Poster sessions death; cotton crop yield loss up to 40-60% has been due to reniform nematode infestations. A production eld nat- urally infested with the reniform nematode and controlled eld microplots are currently being used to study the cor- relation between reniform nematode population thresh- olds and re ectance properties exhibited by infected cot- ton plants. Re ectance properties, measured by a hand- held hyperspectral spectroradiometer, will be used to develop hyperspectral images. These hyperspectral im- ages along with nematode population threshold data will be used to determine relationships between cotton plant stress and nematode population thresholds. Hyperspectral imagery may be a useful remote sensing tool enabling cot- ton producers to test for nematode presence while avoid- ing the time consuming and sometimes costly soil sam- pling process presently used today. 116 Possibilities of auto uorescence in a nematological diagnostic laboratory Loes den N IJS ¤ and Gerrit K ARSSEN Plant Protection Service, P.O. Box 9102, 6700 HC Wageningen, The Netherlands ¤ l.j.m.f.den.nijs@pd.agro.nl Auto uorescence is a phenomenon that scientists often try to avoid because it interferes with the induced uo- rescence they want to measure. We studied green auto u- orescence in free-living and plant-parasitic nematodes at low magni cation (12.5-100 £ ). First observations indi- cate it is useful for the distinction between plant-parasitic and non-plant-parasitic nematodes, endo-parasitic nema- tode detection in roots, nematode viability tests such as live and dead counting of juveniles of potato cysts nema- todes and for detection of other speci c items like Pas- teuria endospores. The Leica MZ FL III dissection mi- croscope has been tested on a variety of nematological objects. The advantages and disadvantages will be high- lighted. 117 Comparison of quantitative PCR and mister extraction for the assessment of Pratylenchus neglectus or P. thornei Sharyn T AYLOR ¤ , Alan M C K AY , Kathy O PHEL -K ELLER , Danuta S ZOT and H ERDINA South Australian Research and Development Institute, GPO Box 397, Adelaide, South Australia 5001, Australia ¤ taylor.sharyn@saugov.sa.gov.au Seven wheat varieties and 13 doubled haploid wheat lines were inoculated with P. neglectus or P. thornei and grown in a glasshouse experiment for 8 weeks. Root systems were washed and nematodes were quanti ed using either a microscope or PCR. For assessment using the microscope, root systems were washed to remove soil, cut and misted for 4 days and the nematode suspension counted using a dissection microscope. For assessment using PCR, plant roots were washed and nematode DNA extracted. PCR (speci c to either P. neglectus or P. thornei ) was used to quantify DNA levels. There was higher variation between replicates with microscope (c.v. D 63%) compared with PCR assessment (c.v. D 22%). This was attributed both to errors associated with extraction using the misting chamber and in sub- sampling and counting the nematode suspension using the microscope. For both P. neglectus and P. thornei, signi cant positive linear correlations were obtained between the microscope and PCR methods ( P. neglectus r 2 D 0 : 80: P < 0 : 001; P. thornei r 2 D 0 : 512: P < 0 : 05). The PCR technique for quantifying P. neglectus or P. thornei is currently being used for screening cereals in southern Australia. 118 Use of the misti er for extraction of root lesion nematodes ( Pratylenchus spp.) from soil Vivien A. V ANSTONE 1 ; ¤ , Caroline A. V ERSTEEG 1 ; 3 , Michelle H. R USS 1 ; 2 and Sharyn P. T AYLOR 2 1 University of Adelaide, Department of Plant Science, pmb 1, Glen Osmond, 5064, South Australia, Australia 2 South Australian Research and Development Institute, GPO Box 397, Adelaide, 5001, South Australia, Australia 3 Department of Primary Industries, Centre for Wet Tropics Agriculture, South Johnstone, 4859, Queensland, Australia ¤ vivien.vanstone@adelaide.edu.au Since 1995, we have used the misti er for extraction of Pratylenchus from eld samples of soil C roots. This required a lter that retained soil, allowed passage of nematodes, and remained intact through 96 h of misting. Coffee lters (Autocup ® , Thomas and Green Ltd, UK or Altra ® Filters Inc., USA) were the most suitable material. Four lters are used per 50 g sample, providing clean extract without hindering passage of nematodes. Extraction and sample variation were compared with the tray method of Whitehead and Hemming using three naturally infested eld soils and pasteurised soil inoculated with cultured P. neglectus . Eighty percent of nematodes from the eld soils were Pratylenchus . Forty Vol. 4(2), 2002 163</p>
<p>Detection and diagnostics (107-122) eight percent more nematodes were extracted by mister than with the tray. Sample variation was similar for mister (16-23%) and tray (12-20%). Numbers recovered (64%) from inoculated soil did not differ between methods. Nematodes in natural soil could have been attached to soil particles or organic matter, contained within roots or anhydrobiotic.These nematodes were therefore extracted more ef ciently by the mister than from the tray, probably due to the greater aeration and water ow on the misti er. For eld soils, extraction by misti er resulted in higher Pratylenchus recovery. 119 PCR-based techniques for nematode diagnosis derived from the study of genetic diversity L. W AEYENBERGE ¤ , M. M ADANI , H. Y U , S.A. S UBBOTIN and M. M OENS Crop Protection Department, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ L.waeyenberge@clo.fgov.be One of the main activities in the Department of Crop Protection (Agricultural Research Centre), is the devel- opment of identi cation and detection protocols. Identi- cation of nematodes based on morphology and morpho- metrics is time-consumingand dif cult due to overlapping of many characteristics. Recently molecular identi cation techniques based on PCR have been developed and suc- cessfully applied for nematode diagnostics. These tech- niques allow identifying genetic markers speci c for cer- tain nematode species or groups of populations. Genetic markers are identi ed by the analysis of PCR products us- ing RFLP, direct sequencing and random PCR approaches like RAPD and AFLP. Markers are used to develop PCR with species-speci c primers for rapid nematode detec- tion and Real Time PCR for nematode quanti cation in samples. The poster presents several PCR-applications used for nematode identi cation in CLO-DGB. 120 PCR multiplex identi cation of single individuals of the Longidorid nematodes, Xiphinema index , X. diversicaudatum , X. vuittenezi and X. italiae using speci c primers from ribosomal genes Xirong W ANG 1 , Nathalie B OSSELUT 2 , Chantal C ASTAGNONE 2 , Roger V OISIN 2 , Pierre A BAD 2 and Daniel E SMENJAUD 2 ; ¤ 1 Nematology Laboratory, South China Agricultural University, GuangZhou, China 2 INRA-USVE, Nematology group, B.P.2078, 06606 Antibes, France ¤ esmenjau@antibes.inra.fr Xiphinema index (XI), X. diversicaudatum (XD), X. vuittenezi (XV) and X. italiae (XIT) are established or putative vectors of several nepoviruses of grapevine. All four species are closely related, which makes them dif cult to identify reliably when only single or few individuals are available. With the aim of nding a solution, a simple diagnostic method was developed. The ITS1 region spanning the 18S and 5.8S ribosomal genes was sequenced in one population of each species, using two conserved primers from these respective genes. Sequence comparisons of ITS1, sized 1132 (XV), 1153 (XI), 1175 (XD) and 1190 (XIT) bp, suggested a genetic proximity between the two established vector species X. index and X. diversicaudatum on the one hand and X. vuittenezi and X. italiae on the other hand. The sequence variability of ITS1 allowed the design of internal sense primers, speci c for each species, which ampli ed, in combination with the same antisense ITS1 primer, a single signature fragment (340 bp for XI, 414 bp for XIT, 591 bp for XV and 813 bp for XD). The primers were successfully used in a multiplex test for the reliable detection of two to four mixed species each represented by a single individual. 121 PCR based methods for the analysis of Dutch soil samples for the presence of root-knot nematodes Carolien Z IJLSTRA ¤ , Dorine D ONKERS -V ENNE , Richard VAN H OOF , Linda K OX and Gerrit K ARSSEN Plant Research International (PRI), P.O. Box 16, 6700 AA Wageningen, The Netherlands; Plant Protection Service (PD), P.O. Box 9102, 6700 HC Wageningen, The Netherlands ¤ c.zijlstra@plant.wag-ur.nl The root-knot nematodes Meloidogyne chitwoodi , M. fallax , M. hapla and M. naasi are regularly found as plant-parasitic nematodes in Dutch agriculture, either present alone or as mixtures. The former two have acquired importance as quarantine pests while M. hapla has also increased importance. All three species cause considerable damage on most agricultural crops. Meloidogyne naasi is also found more frequently in agricultural plots, but its relevance is limited to grasses. Inspection services identify root-knot nematode species generally based on morphological characteristics. In a collaboration between PRI and the PD, analyses 164 Nematology</p>
<p>Poster sessions of nematode samples have been compared. Root-knot nematode composition of samples of approximately 100 nematodes was rst determined morphologically; subsequently, the samples were divided between PRI and PD and analysed using PCR assays for the detection of M. chitwoodi , M. fallax , M. hapla and M. naasi . For the former three species, species-speci c PCR primers already existed; for M. naasi a new species- speci c primer was developed. The results between the three analyses were comparable. With respect to routine diagnostic assays, PCR based assays seem to offer attractive alternatives: they are reliable, sensitive, relatively fast, easy to perform, and do not require nematological expertise. 122 Multiplex detection of nematodes and other soil related organisms using three dimensional micro-arrays Carolien Z IJLSTRA ¤ , Arjen S PEKSNIJDER , Peter B ONANT S and Cor S CHOEN Plant Research International (PRI), P.O. Box 16, 6700 AA Wageningen, The Netherlands ¤ c.zijlstra@plant.wag-ur.nl Detecting the presence of nematodes and other soil related plant pathogens or bene cials in soil samples is helpful to ensure safe and sustainable agriculture. However, the multiplicity of detection assays available for a speci c pathogen leads to a lack of consistency among the various testing agencies and hampers standardisation. Micro-array technology, in which thousands of different oligos or proteins can be spotted on little more than 1 cm 2 , enables the detection of many different target molecules in the same sample with increased speci city. Therefore, micro-arrays can meet the demands for fast, speci c, ef cient, cost-effective, user-friendly and reliable multiplex detection methods for different organisms. To develop the micro-array technology for diagnostic purposes, generic extraction methods for DNA and RNA have to be developed. Secondly, the sensitivity must be improved in order to detect low concentrations of extracted nucleic acids, with generic pre-ampli cation methods. Recently a revolutionary porous capillary solid phase micro-array has been developed. The capacity of this three-dimensional array to bind oligonucleotides is higher than that of a two-dimensional glass array resulting in a higher sensitivity. Moreover, the porous solid phase allows ow through measurements, resulting in fast hybridisation times of only 15 min instead of 18 h as on glass. Recent data to detect plant pathogens in this multiplex setting look promising. Vol. 4(2), 2002 165</p>
<p>Evolution, phylogeny and classication (123-175) 123 Comments on intraspeci c variability in the genus Chiloplacus Thorne, 1937 Joaquín A BOLAFIA , Gracia L IÉBANAS , Pablo G UERRERO and Reyes P EÑA -S ANTIAGO ¤ Departamento de Biología Animal, Vegetal y Ecología, Universidad de Jaén, Campus ‘Las Lagunillas’ s/n, 23071-Jaén, Spain ¤ rpena@ujaen.es The genus Chiloplacus Thorne, 1937 is one of the most widely distributed taxa among cephalobid nematodes, and some of its species are considered to be cosmopolitan. The genus currently includes 30 valid species, plus ten incertae sedis , which show a remarkable interspeci c variability when they are studied under both optical microscopy and SEM. In Andalucía Oriental (SE Iberian Peninsula) the genus is represented by six species: C. demani (Thorne, 1925) Thorne, 1937; C. magnus Rashid & Heyns, 1990; C. minimus (Thorne, 1925) Andrássy, 1959; C. tenuis Rashid & Heyns, 1990; C. trilineatus Steiner, 1940 and Chiloplacus sp. In addition to the usual variability affecting the body length, number of lateral eld incisures, postvulval sac length, tail morphology, etc ., present study has revealed an interesting variability in several features of the lip region: separated or more or less amalgamated lips, labial probolae differing in the shape (biacute or bifurcated) and the length of their branches, cephalic probolae also differing in shape and size, more or less distinct primary and secondary axils, and cephalic margin smooth, serrated or bearing tines. The taxonomic interest of these features is discussed brie y. 124 Evidence for heteroplasmy and recombination in nematode mitochondrial DNA Miles A RMSTRONG 1 ; ¤ , Mark P HILLIPS 1 , Dirk H USMEIER 2 , Frank W RIGHT 2 and Vivian B LOK 1 1 Scottish Crop Research Institute, Dundee, DD2 5DA, Scotland, UK 2 Bioinfomatics and Statistics Scotland, Scottish Crop Research Institute, Dundee, DD2 5DA, Scotland, UK ¤ marmst@scri.sari.ac.uk We previously reported the unusual multipartite arrange- ment of the mtDNA of the potato cyst nematode Glo- bodera pallida. Its mtDNA consists of a population of small, genetically distinct mtDNAs which, presumably, exist in as yet unknown combinations in order to en- code all the proteins necessary for mitochondrialfunction. Recently published biochemical evidence that the enzy- matic machinery necessary for homologous recombina- tion is present in animal mitochondria, along with phy- logenetic evidence that recombination has been a feature of the evolution of primate mtDNA, has challenged the received orthodoxy that animal mtDNA is inherited clon- ally. The existence of a persistent heteroplasmic state as found in G. pallida would seem likely to provide am- ple opportunityfor recombination.We now have evidence of mtDNA recombination both between distinct G. pal- lida mtDNA lineages, and between sub-types of single mtDNA lineages. Recombination is demonstrated using the latest methods from statistical phylogenetics, includ- ing hidden Markov models and Bayesian (Markov chain Monte Carlo) approaches. 125 Conversion of AFLP markers to PCR-based STS markers to identify Heterodera glycines populations N. A TIBALENTJA ¤ , G.R. N OEL and L. D OMIER Department of Crop Sciences, University of Illinois, Urbana, IL 61801, USA; USDA-ARS, Urbana, IL 61801, USA ¤ ndeme@uiuc.edu Nine AFLP markers were identi ed that provide varying degrees of speci city to some of the 48 selected populations involved in a previous study that investigated the parasitic ability of the soybean cyst nematode, H. glycines . The 48 populations were obtained by subjecting eld populationsof races 1 through 6, 9, and 14 to several cycles of selection on each of six sources of resistance to H. glycines : Peking, Cloud, PI88788, PI89772, PI209332 and PI90763. The nine AFLP markers were cloned and their DNA nucleotide sequence determined before they were used to design oligonucleotide primers for PCR-ampli cation of genomic DNA from the original unselected eld populations.Following this procedure, we have generated STS (sequence tag site) primers that are speci c for races 1 through 6, 9, and 14 of H. glycines . These STS markers should be very useful as diagnostic probes for the identi cation of eld populations of H. glycines . 126 Phylogenetic relationships between Paratrichodorus and Trichodorus species (Nematoda: Trichodoridae) Konstantina B OUTSIKA ¤ , Mark S. P HILLIPS , Derek J.F. B ROWN and Vivian C. B LOK 166 Nematology</p>
<p>Poster sessions Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK ¤ kbouts@scri.sari.ac.uk Paratrichodorus and Trichodorus species (trichodorids) are soil-inhabiting ectoparasitic nematodes, several of which are natural vectors of Tobraviruses. Trichodorids used in this study were obtained from colleagues in Europe, North and South America, Asia, and from British soil samples. Phylogenetic analysis of the 18S gene from ribosomal DNA sequence data obtained from 17 different trichodorid species revealed a major differentiation corresponding to the two genera Paratrichodorus and Trichodorus , but P. minor and P. porosus were only distantly related to the other members of their genus. Analysis of the aligned sequences indicated the presence of ‘mosaic’ sequences in the 18S gene of P. minor and P. porosus populations and suggested recombination events. The cuticle is one of the main characters used to distinguish between the two genera and, recently, ne structure of the body cuticle in several trichodorids was found not to be genus speci c. This observation, together with our results with P. minor and P. porosus, suggests that the current divisions in the Family Trichodoridae require a reassessment. 127 Molecular diagnosis of Pratylenchus thornei Susana C ARRASCO -B ALLESTEROS 1 ; ¤ , Pablo C ASTILLO 1 , Encarnación P ÉREZ -A RTÉS 1 and Rafael M. J IMÉNEZ -D ÍAZ 1 ; 2 1 Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible (IAS), Consejo Superior de Investigaciones Cientí cas (CSIC), Apartado 4084, 14080 Córdoba, Spain 2 Escuela Técnica Superior de Ingenieros Agrónomos y Montes, Universidad de Córdoba, Apartado 3048, 14080 Córdoba, Spain ¤ mi2cabas@lucano.uco.es Root-lesion nematodes are economicallyimportant patho- gens of a wide range of crops. This study describes the de- velopment of a species-speci c primer pair designed from a RAPD fragment associated with Pratylenchus thornei , the cereal and legume root-lesion nematode. The RAPD fragment was cloned and sequenced and primers for spe- ci c PCR were developed from sequence data. Speci c PCR analyses using the new primer pair and total ge- nomic DNA extracted from a mixture containing all life stages of the nematode (eggs, juveniles and adult females) rendered a 1050 bp DNA fragment which proved speci c for P. thornei . This fragment was not ampli ed when to- tal genomic DNA from other Pratylenchus spp., Meloido- gyne spp., Heterodera mediterranea , Zygotylenchus gue- varai , Ditylenchus dipsaci and Radopholus similis was used as template in PCR reactions using the newly de- signed primer pair. 128 Studies on the taxonomy of important genera and species of Criconematoidea from China Lijie C HEN ¤ and Weizhi L IU Department of Plant Protection, Shenyang Agricultural University, Shenyang 110161, P.R. China ¤ Chenlj2048@sina.com More than 895 samples from 67 families, 189 genera, 246 species of plants in 73 cities and counties of 17 provinces and autonomous region were examined in China. The important genera, Criconema , Ogma , Dis- cocriconemella , Hemicycliophora , Hemicriconemoides , Criconemella , Paratylenchus and Gracilacus , of Cricone- matoidea from China were systematically observed and identi ed. Forty species from eight genera of Cricone- matoidea were identi ed, including one species of Criconema , one species of Ogma , one new species of Discocriconemella , one species of Hemicycliophora , ve species of Hemicriconemoides , ten species of Cricone- mella , 13 species of Paratylenchus and eight species of Gracilacus . Of the 40 species, there were ve new ones: Discocriconemella sinensis n. sp., Hemicriconemoides parasinensis n. sp., Paratylenchus handansis n. sp., bayansis n. sp., and Gracilacus populus n. sp., and there were 19 new recorded species in China. 129 The nematode collection at the Museum of Comparative Zoology, Harvard University David Bruce C ONN School of Mathematical and Natural Sciences, Berry College, Mount Berry, Georgia 30165 USA and Museum of Comparative Zoology, Dept. of Invertebrate Zoology, Harvard University, Cambridge, Massachusetts 02138 USA bconn@berry.edu The Museum of Comparative Zoology (MCZ) of Harvard University maintains several globally important research collections. The MCZ’s Department of Invertebrate Zoology curates nearly one million specimens, 10 000 of which are type specimens; additionally, entomology and malacology collections are curated by separate Vol. 4(2), 2002 167</p>
<p>Evolution, phylogeny and classication (123-175) departments. The nematode collection is growing, and includes signi cant holdings obtained from several expeditions and studies conducted around the world. Most specimens are parasitic species from animal hosts, but some free-living and plant-parasitic species are included. Most were collected within the past 100 years, but some date closer to MCZ’s founding in 1859. In 1980, MCZ transferred many nematode type specimens to the United States National Parasite Collection, but retained all other nematode specimens. Current collection activities focus primarily on voucher specimens for biotic surveys and ecological and experimental studies. Use of and contribution to the collections by nematologists outside Harvard for scienti c and educational purposes is encouraged, subject to approval by MCZ on a case-by- case basis. 130 Protein variation in potato cyst nematodes revealed by capillary electrophoresis Maria José M. DA C UNHA 1 ; ¤ , Isabel Luci P.M. DA C ONCEIÇÃO 2 , Lúcia M. P IRES 1 , Isabel M. DE O. A BRANTES 2 and M. Susana N. DE A. S ANTOS 2 1 Escola Superior Agrária de Coimbra, Bencanta 2 Instituto do Ambiente e Vida, Departamento de Zoologia, Universidade de Coimbra, 3004-517 Coimbra, Portugal ¤ mjcunha@mail.esac.pt Capillary electrophoresis was used to characterise 49 Portuguese populations of potato cyst nematodes, 46 of Globodera rostochiensis and three of G. pallida , and eight representative populations of pathotypes de ned for these two species (Ro1, Ro2, Ro3 and Ro4 for G. rostochiensis and Pa1, Pa2 and Pa3 for G. pallida ). Protein extracts of 50 cysts per sample were separated using Beckman eCAP SDS 14-200 kit, in a capillary with 57 cm length and 100 ¹ m internal diameter and a run time of 40 min. Reproducible protein pro les were obtained and the populations were compared taking account the relative migration time and area of each peak recorded by the Gold Software Data System. Similarity indices (F) and genetic distances (D D 1-F) between populations were calculated using peak area data and a dendrogram was constructed according to the UPGMA method. Protein pro les of each pathotype were obtained and some of the proteins were characteristic of each pathotype. However, Ro1 and Ro4 were not placed together, and Pa1 was not placed together with Pa2. Portuguese populationsrevealed a great variability and it seems that protein composition is not related to geographic origin of populations. 131 Testing a molecular barcode system against the biological species concept in culture of Panagrolaimus populations Abebe E YUALEM and Mark B LAXTER Institute of Cell, Animal and Population Biology, Ashworth Laboratories, King’s Buildings, West Mains Road, The University of Edinburgh, Edinburgh EH9 3JT, Scotland, UK Previously we developed a molecular barcode system using the 18S of rDNA for de ning a molecular operational taxonomic unit (MOTU) for the identi cation of nematodes from an experimental eld site in the UK. Here we present the result of our attempt to identify ve Panagrolaimus populations from this site, which we maintained in culture, morphologically, molecularly and biologically, i.e ., through breeding each population against the other. The results showed that biologically they belonged to two reproductively isolated species. The available morphological criteria, including SEM, were insuf cient to differentiate between them; thus they probably belong to one species. The variation of the morphometrical data rendered its use subjective, more so it did not discern between the two biological species. The molecular operational taxonomic unit resulted from our barcode system, perfectly agreeing with the breeding results, clearly separated the populations into two groups. While understanding that the work was limited to only ve populations of one genus, we maintain that this congruence of the MOTU concept with the biological species concept in the taxonomically dif cult genus, Panagrolaimus , shows that the method could be promising as it is simple, comparable and transferable, thus universal. 132 Large-scale molecular barcode survey of soil nematodes Robin M. F LOYD ¤ and Mark L. B LAXTER ICAPB, University of Edinburgh, King’s Buildings, West Mains Road, Edinburgh EH9 3JT, Scotland, UK ¤ Robin.Floyd@ed.ac.uk We have developed a molecular barcoding system for identi cation of soil nematodes by DNA sequencing, and here report on the results of our rst major survey. PCR was carried out on individual nematodes, and the 5 0 segment of the small subunit ribosomal RNA (SSU) gene ampli ed and sequenced. Resulting sequences, typically 450-500 bases, were aligned and 168 Nematology</p>
<p>Poster sessions clustered using a neighbour-joining algorithm. Groups of similar or identical sequences were designated as molecular operational taxonomic units (MOTU). Two large-scale surveys were carried out (in July and October 2001) on a Scottish upland Agrostis - Festuca grassland soil (the Sourhope Soil Biodiversity Programme study site), using both molecular and morphological methods in parallel, in collaboration with Dr Eyualem Abebe. Results indicate a general congruence between the two methods, af rming the reliability of the molecular barcode approach. Chemically treated plots (nitrogen, lime, nitrogen C lime and biocide, along with untreated controls) were included in this study, and the effect of these treatments on nematode diversity and distribution was analysed. This study establishes molecular barcoding as a rapid, time-ef cient and robust method for large scale surveys of nematode diversity. 133 A phylogenetic view of longidorids Yu H E 1 ; ¤ , Tatjana R UBTSOVA 1 , Derek J.F. B ROWN 2 , Franco L AMBERTI 3 and Maurice M OENS 1 1 Crop Protection Department, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium 2 Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK 3 Istituto di Nematologia Agraria, CNR, 70126 Bari, Italy ¤ y.he@clo.fgov.be The molecular phylogeny for 77 populations including 62 species of the Longidoridae (24 Longidorus spp., two Paralongidorus spp., 34 Xiphinema spp., and two Xiphidorus spp.) was constructed using Paup 4.0. Sequences obtained from the D2D3 region of the 26S subunit gene located in ribosomal RNA gene clusters were aligned and processed for constructing the phylogram using the maximum likelihood criterion. The species are clustered in two main groups: Longidorus and Xiphinema . Paralongidorus species are grouped with Longidorus africanus . Xiphidorus species are grouped with Xiphinema krugi and the subgroup Xiphinema americanum . Most of the branches obtained good support from non-parametric bootstrap analysis. 134 A proposed polytomous key for the genus Aphelenchoides Sue H OCKLAND Invertebrate Identication Team, Plant Health Group, Central Science Laboratory, Sand Hutton, York, YO41 1LZ, UK s.hockland@csl.gov.uk The genus Aphelenchoides consists of over 140 nominal species, some of which are pathogenic to plants. In this study, a revised list of species was produced, deleting descriptions considered too poor for subsequent recognition. Key diagnostic characters were identi ed and promising features for future diagnostic use were investigated using 14 populations. The primary key characters were identi ed as the length of the post-vulval sac (pvs) as a percentage of the distance between the vulva and the anus, the shape of the tail terminus and tail, body length, and the ratios ‘a’ and ‘c’. Promising key characters for the future are c 0 , the distance from the vulva to the anus, vulval body width, pvs length as a measure of the vulval body width, head width and all measurements associated with the median bulb. A polytomous key was produced, and can be adapted for computer use. Diagnosticians and nominators of new Aphelenchoides species are invited to use the key and its associated recording form to collect more details of morphologicaland morphometric characters in this genus. 135 An interactive electronic key to nematode genera Mike H ODDA CSIRO Entomology, GPO Box 1700, Canberra ACT 2601, Australia mike.hodda@csiro.au Using the DELTA ® system, a database of the character- istics of genera of Australian freshwater aquatic nema- todes and Dorylaimida has been constructed. This data- base lists over 700 characteristics for over 300 genera. The computer program INTKEY ® can be used to inter- rogate this database to key out any genus easily. The data- base has been constructed so that the key will serve a range of users, from novice to expert, and a range of situations, from abundant good material to scarce dam- aged specimens. Characters from any particular part of the body may be omitted or used exclusively. Charac- ters visible with high power microscopy may be used or those visible at relatively low magni cations only may be used (although these do not always lead to identi - cation of a single taxon). All characters may be used, including those speci c to local populations, or strictly taxonomic characters only may be used, leading to iden- Vol. 4(2), 2002 169</p>
<p>Evolution, phylogeny and classication (123-175) ti cations which are by de nition robust for areas out- side the area speci cally covered. Characters suitable for novice and experienced users can also be selected. The key is illustrated, and is available now online free at http://www.ento.csiro.au/science/nematodes. 136 A phylogeny of selected Longidoridae based on 18s rDNA gene sequences J. H ÜBSCHEN 1 ; ¤ , M. DE O LIVEIRA 2 , A. A UWERKERKEN 3 , L. B ARSI 4 , L. F ERRAZ 5 , U. I PACH 1 , S. L AZAROVA 6 , M. L ISKOVA 7 , V. P ENEVA 6 , R. R OBBINS 8 , A. S USULOUSKY 9 , M. T ZORTZAKAI S 10 , W. Y E 8 , J. Z HENG 11 , R. N EILSON 12 and D. B ROWN 12 1 Staatl. Lehr-und Forschungsanstalt fur Landwirtschaft, Weinbau und Gartenbau, Fachbereich Phytomedizin, Breitenweg 71, D-67435 Neustadt/W, Germany 2 Instituto Biologico, Rodovia Heitor Penteado km3, Campinas, SP, Brazil 3 Institute of Tropical Agriculture, High Rainfall Station, Port Harcourt, Nigeria 4 Institute of Biology, Novi Sad, FR Yugoslavia 5 Departamento Zoologia, Universidade de São Paulo, Piracicaba, SP, Brazil 6 Laboratory of General Ecology, So a, Bulgaria 7 Parasitological Institute SAS, Košice, Slovak Republic 8 Nematology Laboratory, University of Arkansas, Fayetteville AR, USA 9 Museum of Natural History, L’viv, Ukraine 10 Plant Protection Institute, Agricultural Research Foundation, Crete, Greece 11 College of Agriculture, Zhejiang University, Hangzhou, China 12 Scottish Crop Research Institute, Dundee, Scotland, UK ¤ jhuebschen.sa-nw@agrarinfo.rpl.de The 18s rDNA gene is highly conserved within taxa, which makes it particularly useful for phylogenetic studies. Phylogenies of several groups of plant-parasitic nematodes have been produced by various authors, but these refer only to endo-or semi-endoparasitic nematodes and have not involved 18s sequence data. The family Longidoridae is comprised of ve genera, with two of these, Longidorus and Xiphinema, comprised of over 100 and 200 species, respectively. Individual specimens from representative populations of longidorids from around the world had their 18s gene fully sequenced. Analyses of the sequence data revealed a clear separation between Xiphinema and Longidorus ; three major clusters of species were apparent in the genus Xiphinema : X. americanum group of species, X. pachtaicum , and the other Xiphinema species with which the genus Xiphidorus clustered. The genus Xiphinema was most closely related to L. camelliae , followed by L. litchi , and then to a cluster that included several Longidorus spp., and two Paralongidorus spp. The remaining clusters of Longidorus spp. revealed strong evidence of geographical origin of the species. 137 Phylogenetic relationships based on 18S sequences among some Xiphinema species with three and four juvenile development stages Judith H ÜBSCHEN 1 ; ¤ , Roy N EILSON 2 , Ulrike I PACH 1 and Derek J.F. B ROWN 2 1 SLFA, Neustadt/Weinstrasse, Germany 2 SCRI, Dundee, Scotland, UK ¤ jhübschen.slfa-nw@agrarinfo.rlp.de Xiphinema americanum -group nematodes, comprising of approximately 50 putative species, have a cosmopolitan distribution and are known to vector four economically damaging viruses; consequently these nematodes are an important global agricultural pest. Previous studies have concluded that some species within the X. americanum - group have three juvenile stages with other species having four juvenile stages. Morphological characterisation of this group is problematical due to similarities of many of the taxonomic characters across the entire group. This lack of taxonomic resolution has crucial concomitant implications when trying to assess virus- vector relationships, i.e. , which species vector a particular virus. Analyses of 18S gene sequence have previously been reported to discriminate taxonomic units in many organisms including nematodes. 18S data showed that all the Asiatic (Chinese) populations of X. americanum , including those with three or four juvenile stages, were genetically identical inferring a single species. In contrast, speciation was evident in the studied populations from both North America and Europe. Furthermore, our data suggested that a greater genetic diversity existed in the studied European populations that originated from a smaller geographic area than the studied populations that originated in either North America or Asia. 138 Molecular diagnostics for virus-transmitting nematodes in German viticulture Judith H ÜBSCHEN 1 ; ¤ , Ulrike I PACH 1 , 170 Nematology</p>
<p>Poster sessions Volker Z INKERNAGEL 2 , Daniel E SMENJAUD 3 , Derek J.F. B ROWN 4 and Roy N EILSON 4 1 Staatliche Lehr- und Forschungsanstalt für Landwirtschaft, Weinbau und Gartenbau, Fachbereich Phytomedizin, Breitenweg 71, D-67435 Neustadt/W., Germany 2 Technische Universität München, Lehrstuhl für Phytopathologie, Am Hochanger 2, D-85350 Freising-Weihenstephan, Germany 3 Institut National de la Recherche Agronomique, F-06600 Antibes, France 4 Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK ¤ jhuebschen.slfa-nw@agrarinfo.rlp.de Virus-free grapevine plants required for viticulture have to be grown in soil free from virus-transmitting nematodes. Current soil testing methods are laborious and require highly experienced staff as they rely on morphological examination of the nematodes. Molecular diagnostics provide a simple and reliable alternative, but are not available for virus-transmitting nematodes. To develop this method for application with samples from German vineyards, we investigated species-speci c primers for the most important nematodes in German viticulture viz ., Xiphinema index, X. diversicaudatum and X. vuittenezi . The 18S gene of rDNA, which is highly conserved in taxa, was sequenced using three primer pairs for ten, eight and four populations of these three species to con rm the homogeneity of each species. The genetic variation between the species was low. Consequently, in the rst instance, species-speci c primers identi ed from the genetically variable ITS-1 region of rDNA for each of these species, developed by INRA France, were used in interaction tests in PCR to con rm their speci city and robustness when used for detecting the species occurring in soil samples from German vineyards. Primer sets are also being developed for Longidorus and Paralongidorus virus-vector species. The preliminary results from these tests are presented and discussed. 139 Genetic variability of Meloidogyne mayaguensis isolates from the Caribbean A. K ERMARREC 1 , S. P ANOMA 1 , P. Q UÉNÉHERVÉ 2 , H. M AULEON 1 and P. C ASTAGNONE -S ERENO 3 1 INRA-URPV, Domaine Duclos, 97270 Petit Bourg, Guadeloupe 2 IRD, BP 8007, 97259 Fort-de-France Cedex, Martinique 3 INRA-IPMSV, BP 2078; 06606 Antibes Cedex, France Meloidogyne mayaguensis Rammah & Hirschmann,1988 has been recently identi ed in the French West Indies from guava ( Psidium guayava ) orchards. This very aggressive root-knot nematode seems already widely distributed in the Caribbean (Cuba, Dominican Republic, Puerto Rico, Guadeloupe, Martinique). The objective of this study was to evaluate the genetic variability of M. mayaguensis isolates from several locations in the Caribbean, in comparison with African isolates from Burundi and Congo. For that purpose, nematodes were characterised using both isozyme electrophoresis and RAPD-PCR. At the biochemical level, for the two enzymatic systems used (EST and MDH), all the isolates shared the same electrophoretic pro les. At the molecular level, except one isolate from Martinique, RAPD analysis revealed a high level of genetic similarity ( > 78%) between all isolates. The UPGMA dendrogram deduced from the RAPD patterns showed that clustering of isolates neither re ected their geographic origin nor indicated how they might have been spread. Despite having been sampled from very distant locations, such a relative lack of genetic polymorphism suggests a common origin for all the M. mayaguensis isolates tested, and indicates that they may have been dispersed from a single source instead of representing local indigenous populations. 140 Four new species of soil nematodes (Nematoda: Dorylaimida) from Japan Zakaullah K HAN ¤ and Masaaki A RAKI National Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki 305-8604, Japan ¤ nema@yahoo.com During the course of studies on biodiversity of soil nematodes in Japan, four new species of soil nematodes belongingto the order Dorylaimida were isolated from the soil samples collected from a non-tillage eld of National Institute for Agro-Environmental Sciences, Tsukuba, Japan. Specimens killed in hot water were xed in TAF, processed to anhydrous glycerin and mounted on slides. Specimens were observed under optical microscope and measured with the help of drawing tube attachment. Measurements and characteristics of these new species are as follows: Egtitus n. sp. is 1.7-2.0 mm long, a D 41-46, b D 3.9-4.3, c D 15-19, V D 50-53, odontostyle D 21- 23 ¹ m, and is characterised by having sinuate odontostyle and smaller prerectum. Axonchium n. sp. having 1.5-1.6 mm long body, a D 39-43, b D 2.5-2.6, c D 48-54, V D 50- 52, odontostyle D 9-11 ¹ m, and is distinguishable by its Vol. 4(2), 2002 171</p>
<p>Evolution, phylogeny and classication (123-175) larger body and absence of post-uterine sac. Chitwoodius n. sp. measuring 1.0-1.2 mm long, a D 26-31, b D 3.4-4.1, c D 47-55, V D 61-64, odontostyle D 30-33 ¹ m, spicules D 48-55 ¹ m and is characterised by having posteriorly located guiding ring and larger prerectum. Labronema n. sp. is 1.0-1.2 mm long, a D 22-25, b D 3.6-4.0, c D 47-50, V D 50-52, odontostyle D 20-21 ¹ m, spicules D 55 ¹ m and is characterised by smaller body and sub-digitate tail. 141 Four new species of soil nematodes (Nematoda: Dorylaimida) from Japan Zakaullah K HAN and Masaaki A RAKI ¤ National Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki 305-8604, Japan ¤ arachis@niaes.affrc.go.jp During the course of a study on biodiversity of soil nematodes in Japan, four new species of soil nematodes belonging to the order Dorylaimida were isolated from the soil samples collected from a non-tillage eld of the National Institute for Agro-Environmental Sciences, Tsukuba. Specimens killed in hot water were xed in TAF, processed to anhydrous glycerin and mounted on slides. Specimens were observed under optical microscope and measured with drawing tube. Measurements and characteristics of these new species are as follows: Axonchium n. sp. is 1.5-1.6 mm long, a D 39-43, b D 2.5-2.6, c D 48-54, V D 50-52, odontostyle D 9- 11 ¹ m, and is distinguishable by its larger body and absence of post-uterine sac. Egtitus n. sp. is 1.7-2.0 mm long, a D 41-46, b D 3.9-4.3, c D 15-19, V D 50-53, odontostyle D 21-23 ¹ m, and is characterised by having sinuate odontostyle and smaller prerectum. Labronema n. sp. is 1.0-1.2 mm long, a D 22-25, b D 3.6-4.0, c D 47-50, V D 50-52, odontostyle D 20-21 ¹ m, spicules D 55 ¹ m and is characterised by smaller body and sub- digitate tail. Prodorylaimus n. sp. measuring 1.3-1.5 mm long, a D 37-40, b D 3.8-4.0, c D 5.1-6.0, V D 50-53, odontostyle D 21-24 ¹ m, and is characterised by having rounded lip region and gradually tapering to long liform tail. 142 Inter-population variability in Pratylenchus vulnus Allen & Jensen, 1951 (Nematoda: Tylenchida) Paola L AX 1 ; ¤ , Marcelo E. D OUCET 1 , Julio A. D I R IENZO 2 , Pierre B AUJARD † and Jorge P INOCHET 3 1 Laboratorio de Nematología, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, C.C. 122, 5000. Córdoba, Argentina 2 Unidad de Procesamiento Electrónico de Datos, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, C.C. 509, 5000, Córdoba, Argentina 3 Agromillora Catalana S.A. El Rebato s/n, 08737 Subirats, Barcelona, Spain † deceased ¤ plax@arnet.com.ar Data corresponding to morphometrical characters of males and females belonging to populations of Praty- lenchus vulnus from different geographicorigin and under different developmental conditions were considered. An inter and intra-populationvariance was estimated for each character as well as the percentage of inter-population variance. Characters were grouped into three categories (low, medium and high variability). Considering those percentages, it was observed that the number of characters with low variability was higher in females than in males, being inverse in the case of characters with high variabil- ity. Depending on the percentage of inter-populationvari- ability for each character, it was inferred that those char- acters included in the low variability category would be barely in uenced by environmental conditions, whereas those characters related to high values would be consider- ably in uenced. Therefore, not all characters would have the same signi cance. Some of them appear to be more signi cant than others for the species identi cation (V ra- tio and spicule length for males and females, respectively, ratios O, MB, c 0 , pharynx length) whereas other group of characters should be preferably considered when evaluat- ing the existence of possible differences between popula- tions. 143 Genetic variability in two populations of Heterodera glycines Ichinohe, 1952 from Argentina estimated with RAPD-PCR markers Paola L AX 1 ; ¤ , Juan C. R ONDAN D UEÑAS 2 , Cristina N. G ARDENAL 2 and Marcelo E. D OUCET 1 1 Laboratorio de Nematología, Centro de Zoología Aplicada, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, C.C. 122, 5000, Córdoba, Argentina 2 Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, C.C. 35, Sucursal 16, 5016, Córdoba, Argentina ¤ plax@arnet.com.ar 172 Nematology</p>
<p>Poster sessions The genetic variability of two populations of H. glycines was analysed using Random Ampli ed Polymorphic DNA (RAPD-PCR) as markers. Thirty females of a population belonging to race 1 from Laguna Larga (Córdoba Province) and 31 females from a population of race 3 from Tortugas (Santa Fe Province) were studied individually. Twenty random primers from Biodynamics (Buenos Aires, Argentina) were tested. Five of them were selected because they originated reproducible polymorphic bands. Thirty nine consistent fragments were considered for the analysis. Allele frequencies were estimated assuming RAPD segregate as dominant and that the populationswere in Hardy-Weinberg equilibrium. Proportion of polymorphic loci was 100% in both populations; mean expected heterozygosity (He) among individuals was 0.39 and 0.42 for females from Laguna Larga and Tortugas, respectively. F ST values were signi cant ( P < 0 : 05) for 67% of the loci. The AMOVA test showed a variation of 81.2% within specimens of a population, while the remaining 18.8% accounted for differences between populations. None of the populations presented exclusive bands, although many fragments showed signi cant differences in their frequencies. This study revealed a high intra-population variability and an important degree of genetic differentiation between populations of races 1 and 3. 144 Phylogeny of Meloidogyne spp. based on rDNA-ITS sequence and uorescent AFLP Jinling L IAO 1 ; 2 ; ¤ , Zhixin F ENG 2 and Weicai Y ANG 1 1 Institute of Molecular Agrobiology, Research Link 1, National University of Singapore, Singapore 117604 2 Plant Nematology Laboratory, South China Agricultural University, Guangzhou, PR China 510642 ¤ liaoima@hotmail.com A phylogenetic study of 12 populations of M. incognita , two populations of M. arenaria, two populations of M. javanica and newly-described M. panyuensis n. sp. was performed on rDNA-ITS sequences and uorescent AFLP. For the rDNA-ITS sequence analysis, genomic sequences containing the partial 18S, complete ITS and partial 26S regions were PCR ampli ed, cloned and sequenced. Sequence analysis using the neighbour- joining cluster method showed that it is dif cult to establish a reasonable phylogenic relationship among the four species since the tree topology does not match with the established taxonomy. For AFLP analysis, 42 primer combinationswere screened and AFLP with a total number of ampli ed polymorphic fragments of 1267 from ten primer combinations were analysed with NTSYS-pc package. Populations from each species form a single clade and the phylogenic relationship matches very well with previous phylogeny. Meloidogyne arenaria and M. javanica are closely related and form a branch that is monophyleticto M. incognita. Meloidogynepanyuensis is distantly related to the other three species. We concluded that AFLP is more reliable than rDNA-ITS sequences for nematode phylogenic study since AFLP covers the whole genome whereas rDNA-ITS sequences come from only one locus. Furthermore, AFLP is much simpler than rDNA-ITS sequencing. 145 Enzymatic characterisation of Meloidogyne spp. associated with ornamentals and agronomic crops in Florida, USA R.D. L IMA 1 ; ¤ , J.A. B RITO 2 , D.W. D ICKSON 3 , W.T. C ROW 3 , C.A. Z AMORA 2 and M.L. M ENDES 3 1 Depto de Fitopatologia, Universidade Federal de Viçosa, 36571-000 Viçosa, MG, Brazil 2 Division of Plant Industry, Gainesville, FL, 32618-7100, USA 3 Entomology and Nematology Dept., University of Florida, Gainesville, FL 32611-0620, USA ¤ rdlima@ufv.br The use of enzyme phenotypeshas made the identi cation of species of Meloidogyne less subjective and more ac- curate. Biochemical analysis based on phenotypes of es- terase (EST), malate dehydrogenase (MDH), superoxide dismutase (SOD), and glutamate-oxaloacetate transami- nase (GOT) was used to characterise 52 populations of Meloidogyne spp. collected from ornamentals and agro- nomic crops in Florida. Meloidogyne javanica, J3 phe- notype, was the most common species (38.4%), followed by M. arenaria phenotype A2 (25.0%), M. incognita phe- notypes I1 (15.4%) and I2 (7.6%), M. graminis (9.6%), and Meloidogyne sp. (3.8%). Meloidogyne graminis had only one slow moving activity EST band which was not present in any of the other phenotypes, three SOD bands (two intensely stained and a third less intensely stained but faster moving band), and one intensely stained MDH band identical to that of M. mayaguensis . The occurrence of M. javanica in peanut is being reported for the rst time in Florida, USA. Vol. 4(2), 2002 173</p>
<p>Evolution, phylogeny and classication (123-175) 146 Variability among isolates of Pratylenchus penetrans for an interaction with Verticillium dahliae and the potato early dying disease A. M ACGUIDW IN ¤ , A. R EID -R ICE , R. R OWE and M. O MAR University of Wisconsin, Madison, WI; OARDC, Ohio State University, Wooster, OH, USA ¤ Aem@plantpath.wisc.edu A synergistic interaction of Pratylenchus penetrans and Verticillium dahliae for the potato early dying disease has been demonstrated using a variety of potato cultivars and soil types. The purpose of our study was to determine if geographic isolates of P. penetrans vary for this interaction. We tested eight P. penetrans isolates from Wisconsin and one each from Washington, Minnesota and Ohio in a series of growth chamber experiments. Three- week-old potato cv. Russet Burbank grown from tissue culture was inoculated with nematodes and 1 week later with conidia of V. dahliae . Control plants were inoculated with only V. dahliae or mock inoculatedwith water and no pathogens. The isolates were ranked for the time required for three leaves to become symptomatic and area under the disease progress curve, as well as for population attributes such as female:male ratio and the rate of root egress. Three isolates from Wisconsin represented the range of variability for symptom expression; two ranked in the top third and one ranked in the bottom third consistently, but all isolates were able to cause disease in combination with V. dahliae . 147 Identi cation of some cyst-forming nematodes based on PCR-RFLP, sequence of rDNA and speci c primers Mehrdad M ADANI 1 ; ¤ , Nicola V OVLAS 2 , Sergei A. S UBBOTIN 3 and Maurice M OENS 1 1 Department of Crop Protection, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium 2 Istituto di Nematologia Agraria del C.N.R., 70126 Bari, Italy 3 Institute of Parasitology of the Russian Academy of Sciences, Leninskii prospect 33, Moscow, 117071, Russia ¤ m.madani@clo.fgov.be More than 50 populations of cyst-forming nematodes collected in Italy and Belgium were analysed using PCR- RFLP, ITS-rDNA sequences, and PCR with species- speci c primers. Restriction of PCR products by eight restriction enzymes AluI , AvaI , Bsh1236I , CfoI , HaeIII , MvaI , PstI and RsaI allowed the identi cation of several agriculturally important cyst nematode species and separation from their sibling species. RFLP pro les for some European populations of Globodera pallida , G. rostochiensis, Heterodera carotae, H. ci, H. lipjevi, H. goettingiana, H. hordecalis, H. humuli, H. mediterranea, H. riparia and H. schachtii are given. The species- speci c primer developed by Bulman and Marshall clearly discriminated G. pallida from G. rostochiensis. Bsh1236I digestion of the PCR product separated both Globodera species from each other and from G. tabacum. Comparison of obtained sequences with those deposited in GenBank showed high similarities (99.8-100%). Relative high level of sequence divergence between populationsof H. hordecalis (1.5%) suggests the presence of several biological species presently grouped under this taxon. 148 Intraspecies DNA polymorphism in the tobacco cyst nematode complex ( Globodera tabacum ) using AFLP Laurent M ARCHÉ ¤ , Eric G RENIER , Sylvie V ALETTE and Didier M UGNIÉRY INRA UMR Biologie des Organismes et des Populations appliquée à la Protection des Plantes, Domaine de la Motte, B.P. 35657, 35653 Le Rheu cedex, France ¤ marche@rennes.inra.fr AFLP was used to obtain information on the within- species genetic variability of the tobacco cyst nematodes (TCN) complex. AFLP was found to be well suited for this type of study. The current classi cation of TCN was con rmed. Results indicate that the Globodera tabacum solanacearum group, believed to be restricted to the USA, also occurs in Mexico. The within-species variability of the TCN is considerable. Populations from Mexico may form a new sub-group. AFLP group-speci c markers were identi ed for two TCN subgroups: Globodera tabacum tabacum and Globodera tabacum solanacearum . 149 Reconstructing a phylogeny of Dorylaimida (Nematoda) with partial 18s sequence data using Bayesian inference Peter G. M ULLIN ¤ , Timothy S. H ARRIS and Thomas O. P OWERS Department of Plant Pathology, 406 Plant Sciences Hall, University of Nebraska-Lincoln, Lincoln, NE 68583-0722 USA ¤ pmullin@biocomp.unl.edu 174 Nematology</p>
<p>Poster sessions Evolutionary relationships among members of Dorylaim- ida are investigated using approximately 600 bp of the 18s ribosomal DNA repeat. Sequence data obtained from selected taxa within Dorylaimida and from several re- lated groups form the basis for the analyses. Results ob- tained under a range of optimality criteria and using sev- eral different methods, including parsimony, distance, and likelihood approaches, are presented and compared. The use of Bayesian inference in phylogeny reconstruction al- lows the combination of detailed likelihood models of DNA evolution with an assessment of the reliability of the results by summarising the posterior probabilities of an extensive sample of trees generated under a given set of model parameters. The resulting consensus tree, with summary branch lengths and clade credibility values, is analogous to a maximum likelihood bootstrap tree, but can be generated in a fraction of the time. We present a phylogenetichypothesis for Dorylaimida and related taxa, along with discussion of several points of departure from recent classi cation schemes of this important group of terrestrial nematodes. 150 Genetic differentiation of individuals and populations of the endoparasitic nematode, Globodera pallida , using microsatellites Roy N EILSON 1 ; ¤ , Vivian C. B LOK 1 , Jim W. M CNICOL 2 and Mark S. P HILLIPS 1 1 Scottish Crop Research Institute, Dundee, DD2 5DA, Scotland, UK 2 Bioinfomatics and Statistics Scotland, Scottish Crop Research Institute, Dundee, DD2 5DA, Scotland, UK ¤ roy.neilson@scri.sari.ac.uk The genetic differentiation of eight populations of the endoparasitic nematode Globodera pallida with known virulence characteristics was assessed at the individual nematode level using six microsatellite loci. This provided an opportunity to assess levels of genetic diversity between and within populations at a resolution that hitherto has not been possible. Intra-population genetic variability was evident, with four populations, Luffness, P5A, Gourdie and Halton being least genetically variable. Although Globodera pallida is a sedentary endoparasite and sexually reproducing species, F ST values and heterozygositydata suggested that it had characteristics of an in-breeding species and supports published hypotheses postulating that many of the European G. pallida populations arose via multiple founder effects. Principal coordinate analyses derived from a) dissimilarity values and b) mean F ST values from an analysis of molecular variance, separated the eight G. pallida populations into four similar putative groupings. As with previous studies, P5A was distinct from all European populations and Luffness (and Lindley) were disparate from the other UK populations. The remaining populationsformed two groupings suggesting further genetic differentiation between UK populations. 151 Variability of Meloidogyne exigua on coffee crops in the Zona da Mata of Minas Gerais State, Brazil Dagoberto Saunders O LIVEIRA , Rosangela D’Arc L IMA and Rodrigo Vieira S ILVA Depto de Fitopatologia, Universidade Federal de Viçosa, 36571-000, Viçosa, MG, Brazil ms40179@correio.cpd.ufv.br Minas Gerais State is the most important producer of cof- fee in Brazil and 28% of its production occurs in the Zona da Mata region. Four major species of root-knot nematodes attacking coffee plants have been reported in Brazil, and some of them can cause plant death. The cor- rect identi cation of species and/or race(s) of Meloido- gyne present in roots of coffee is extremely important in deciding which measures are more appropriate for con- trolling the pathogens. In order to determine the occur- rence and variability of Meloidogyne spp. in the region, 57 populationsfrom 16 different locations were evaluated based on morphologic, enzymatic and physiologic traits. All of the 57 populations were identi ed as Meloidogyne exigua based on their perineal patterns. This characterisa- tion was con rmed by phenotypes of esterase, malate de- hydrogenase, sulphoxide dismutase and glutamate oxalo- acetate transaminase. Thirteen populations presented the typical esterase phenotype showed by one band (VF1), while most of the populations (77.2%) exhibit a pheno- type showed by two bands. No intraspeci c variability was observed in the populations studied, and all of them were able to reproduce on tomato, pepper, cocoa, onion, bean and soybean. 152 Molecular characterisation of some species of the genus Meloidogyne from China Deliang P ENG 1 ; ¤ , Sergei A. S UBBOTIN 2 and Maurice M OENS 3 Vol. 4(2), 2002 175</p>
<p>Evolution, phylogeny and classication (123-175) 1 Institute of Plant Protection of Chinese Academy of Agricultural Sciences, Beijing, 100094, China 2 Institute of Parasitology of Russian Academy of Sciences, Leninskii prospect 33, Moscow, 117071, Russia 3 Agriculture Research Center, Crop Protection Department, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ dlpeng@95777.com rDNA-ITS RFLP and sequence analyses were used for identi cation and characterisation of ten Meloidogyne populations from China. The ITS regions were ampli ed using F195 and 5367 primers. PCR resulted in a single fragment of about 700 bp for all samples. Based on morphological and morphometrical characters, and ITS sequences, seven populations were identi ed as M. hapla , M. javanica, M. arenaria , M. incognita and M. enterolobii , while three populations belonged to two undescribed species. Twelve restriction enzymes were used for digestion of PCR products. The RFLP patterns generated by HinfI C RsaI separated all populations into three groups. None of the enzymes differentiated M. incognita , M. arenaria and M. javanica from each other. The RFLP and sequence analyses of the D2-D3 regions of the 28S gene permitted separation of several root-knot nematode species. 153 rDNA restriction fragment length polymorphism of Heterodera avenae in China Deliang P ENG 1 ; ¤ , Sergei A. S UBBOTIN 2 and Maurice M OENS 3 1 Institute of Plant Protection of Chinese Academy of Agricultural Sciences, Beijing, 100094, China 2 Institute of Parasitology of Russian Academy of Sciences, Leninskii prospect 33, Moscow, 117071, Russia 3 Agriculture Research Center, Crop Protection Department, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ dlpeng@95777.com The ampli cation of the rDNA-ITS region of Heterodera avenae (CCN) from China and Morocco with the current primers AB28 and TW81 yielded one fragment of approximately 1060 bp. A total of 27 scored fragments were obtained with 12 restriction enzymes. Intraspeci c polymorphism was revealed within H. avenae by Alu I, Rsa I and Hinf I digestion. Alu I and Rsa I digestion of ITS products of seven Chinese CCN populations yielded two fragments respectively (560 bp, 500 bp; 720 bp, 320 bp); but neither Alu I nor Rsa I could digest ITS product of Morocco. Those RFLP pro les revealed by Alu I and Rsa I classi ed the ITS of Chinese populations as ‘Type B’ according to Subbotin et al. (2000). Digestion by Alu I also showed heterogenecity in ITS regions of Morocco population, and two additional bands were obtained; the sum of the three fragments was approximately 2120 bp. Hinf I digested PCR ampli ed ITS products of Chinese populations obtained two fragments (850 bp, 200 bp), but obtained three fragments (510 bp, 340 bp, 200 bp) from Morocco population. The results showed that Chinese populations may be distinctly different from Morocco population. Seven enzymes Cfo I, Bsh1236 I, MsrF I, ScrF I, Hae III, Mva I, Msp I produced restriction pro les identical for all CCN populations. Hind III and Ava I did not digest the ITS products of Chinese and Morocco CCN populations. 154 Genetic variability of Heterodera schachtii populations in the north of France inferred by microsatellite loci Olivier P LANTARD ¤ , Catherine P ORTE and Eric G RENIER INRA UMR Biologie des Organismes et des Populations appliquée à la Protection des Plantes, Domaine de la Motte, B.P. 35657, 35653 Le Rheu cedex, France ¤ Plantard@rennes.inra.fr A better knowledge of the genetic structure of phytopar- asitic nematode populations is essential to control these organisms, notably in the context of the use of resistant varieties leading to the selection of virulent individuals able to overcome resistance genes. With that aim, we rst studied the genetic variability of nematode populations at various spatial scales using neutral genetic markers in elds where no resistant varieties have been grown until now. Our study focused on the sugar beet cyst nematode ( Heterodera schachtii ) in the north of France. Using ve microsatellite loci on individuals sampled according to a hierarchical design, an Analysis of MOlecular VAriance (AMOVA) indicates that almost all the genetic variability is observed at the eld scale (94% of the total genetic vari- ability), with only 4% variability observed among elds of the same region and 2% among regions. This suggests that signi cant gene ows occur among elds and regions pre- venting genetic differentiation. In this diploid amphimic- tic species, Hardy-Weinberg equilibrium is observed only at the smaller spatial scale ( i.e. , the individualplant), prob- ably as a result of limited dispersal of individuals in the soil between hatching and mating. 176 Nematology</p>
<p>Poster sessions 155 The differential host test, mtDNA and rDNA PCR to distinguish Meloidogyne arenaria, M. incognita and M. javanica from vineyards Motiul Q UADER ¤ and Ian T. R ILEY Cooperative Research Centre for Viticulture, P.O. Box 154, and Applied and Molecular Ecology, Adelaide University, Glen Osmond, SA 5064, Australia ¤ motiul.quader@student.adelaide.edu.au The North Carolina (NC) differential host test and mtDNA were used to distinguish a collection of root- knot nematodes from South Australian vineyards. PCR ampli cations of D3 expansion region of 28S rRNA gene and intergenic sequences of ribosomal DNA (IGS-rDNA) were also made to distinguish Meloidogyne arenaria, M. incognita and M. javanica . The NC differential host test differentiated Meloidogyne incognita but not M. arenaria race 2 from M. javanica . The combination of the NC host test and mtDNA analysis differentiated among M. arenaria, M. incognita and M. javanica . The differentiation of these species with D3 expansion region of 28S rRNA gene was not possible. The sequences of this region are highly conserved among the species. The PCR ampli cation of IGS-rDNA from single females of each species produced distinct banding patterns that differentiated the species from each other. These species- speci c banding patterns were reproducible across a range of individual nematodes of each species collected from different geographical locations of Australia. This method also produced DNA ngerprint variability within some individuals of each species. This variability could be applied to the examination of intraspeci c variation and potentially development of race speci c diagnostic marker(s). 156 A new species-speci c satellite DNA family in the genome of the coffee root-knot nematode, Meloidogyne exigua Onivaldo R ANDIG , Michel B ONGIOVANNI and Philippe C ASTAGNONE -S ERENO ¤ INRA Unité IPMSV, BP2078, 06606 Antibes cédex, France ¤ pca@antibes.inrafr A new satellite DNA family has been cloned in the coffee root-knot nematode, Meloidogyneexigua. It is represented as tandemly repeated sequences with a monomeric unit of 277 bp. The repeats are present at approximately 17 900 copies per haploid genome, and represent about 9.7% of the total genomic DNA. Twenty independent monomers have been cloned and sequenced. They are very homogeneous in sequence, with 2.4% average divergence from the deduced consensus. This result strongly suggests that this repeated family originated from a recent ampli cation event. Dot-blot experiments demonstrated that the satellite DNA distribution is limited to M. exigua isolates only. In squash-blot assays, it was possible to detect and positively identify single nematodes, independently of their developmental stage. Therefore, because of its high reiteration in the genome, and its species-speci city, this sequence could be used as a probe for the molecular diagnosis of the nematode. 157 Genetic diversity in eld populations of tobacco cyst nematode in North Carolina Uma R AO 1 ; ¤ and D. M C K.B IRD 2 1 Division of Nematology, Indian Agricultural Research Institute, New Delhi 110012, India 2 Department of Plant Pathology, North Carolina State University, Raleigh, USA ¤ Umarao1@yahoo.com Tobacco cyst nematode (TCN) is a fast spreading nematode problem in North Carolina requiring an ef cient method of management. Resistant varieties are a good alternative to chemical nematicides. Quanti cation of genetic diversity is essential to decide the type of resistance to be incorporated. Cysts collected from infested elds of tobacco in Vance, Warren and Surry counties were used for RAPD-PCR analysis. Fourteen eld samples for inter-population diversity and four populations, one from each county, for intra-population diversity were used. The size of the PCR ampli ed products varied from 220 to 2500 bp and the number of products varied from 11 to 22. UPGMA clustering grouped 13 populations into two major clusters at nodal interjunctions of 47 and 58%. One population was heterogeneous enough to fall out of these two clusters. For within population, percentage similarity ranged from 36 to 56 indicating considerable amount of genetic diversity. The heterogeneity observed in TCN suggests that breeding for resistance should be horizontal or broad enough to manage the damage at threshold levels. 158 The development of a query system for the Brazilian nematological bibliography references through the Internet Vol. 4(2), 2002 177</p>
<p>Evolution, phylogeny and classication (123-175) V. R ISSOLI 1 ; ¤ , R. T ENENTE 2 , L. P ALHARES 2 and M. T ENENTE 2 1 Universidade Católica Brasília, QS 7-Lote 1 (72022-900) Taquatinga Sul, DF, Brazil 2 EMBRAPA Recursos Genéticos e Biotecnologia, P.O. Box 2372 (70849-970) Brasília, DF, Brazil ¤ vandor@ucb.br Several bibliographical sources regarding nematode themes are organised in a bank and this will be put in a database which the Nematode Query System will access, for use via the Internet. When one wants to access nematode data, the search for such data becomes an arduous task for professionals. A standard form of systematic classi cation of such bibliographical sources is very important. In this context, the construction of a database in computational environment allows the data to be stored in a systematic and standard way, allowing ef cient data recovery. Recently, EMBRAPA Genetic Resources and Biotechnology and Brasilia Catholic University have been constructing a database of these references which include several species of nematodes and plants belonging to different botanical families. This database allows a search of Brazilian publications including the distribution in Brazil and types of control. Currently, this database has 1850 bibliographical references recovered from 1981 to 2001. The nematode query system, which is a system of access to bibliographical references databases, is now under construction and will be accessible at EMBRAPA Center. A search of the nematode query system can be done by using the scienti c name of either the nematode or the host plant. 159 A simple molecular diagnostic of marine Enoplida L. R OUSSINE 1 ; ¤ , P. D E L EY 2 , V.V. A LESHIN 1 and N.B. P ETROV 1 1 Belozersky Institute of Physico-Chemical Biology, Department of Evolutionary Biochemistry, Moscow State University, 119899 Moscow, Russia 2 Department of Nematology, University of California, Riverside, CA 92521, USA ¤ roussine@yandex.ru Marine Enoplida constitute a group of free-living ma- rine nematodes, which do not share any known morpho- logical synapomorphy. On SSU rRNA phylogenies the group also lacks solid statistical support. In recent studies it was found that an enoplid nematode Trefusia zostericola possesses a rare nucleotide substitution within the region of hairpin 35 of the SSU rRNA secondary structure. The same substitution is common for all 17 Enoplida species studied to date, including Trefusia and Xenella (Trefusi- idae), but is absent from other nematode lineages includ- ing Triplonchida and Dorylaimia. Thus, the substitution can be considered a molecular synapomorphy of Enopl- ida and Trefusiidae. Apart from this substitution,Enoplida are found to share a rare transversion in the loop of hairpin 48. This substitution is not strictly speci c for Enoplida, as it is also known from Mesorhabditoidea and selected non-nematode taxa. These signatures may be used in de- signing speci c primers and be considered as markers of the divergent sequences of marine Enoplida. 160 SSU rRNA gene of Soboliphyme baturini Petrow, 1930 (Nematoda: Dioctophymida) and a reappraisal of molecular bounds of Dorylaimia L. R OUSSINE 1 ; ¤ , V.V. A LESHIN 1 , A.V. T CHESUNOV 2 and G.I. A TRASHKEVICH 3 1 Belozersky Institute of Physico-Chemical Biology, Department of Evolutionary Biochemistry 2 Faculty of Biology, Moscow State University, Department of Invertebrate Zoology, 119899 Moscow, Russia 3 Institute of the Biological Problems of the North, Far-Eastern Branch of the Russian Academy of Sciences, 685000 Magadan, Russia ¤ roussine@yandex.ru Molecular phylogenies based on SSU rDNA sequence data suggest that Dorylaimia, along with Enoplia and Chromadoria, constitutes the third mainstream in nematode evolution. Its contents are represented as follows: (Trichinellida (Dorylaimida (Mononchida: Mermithida))). However, high rates of sequence evolu- tion inherent in the trichinellid lineage render this topol- ogy unreliable. Novel molecular data on the SSU rRNA gene structure of Soboliphyme baturini (Dioctophymida: Soboliphymidae) revealed the fth lineage within Dory- laimia and provided new information for establishing its internal topology. Maximum parsimony, maximum like- lihood and neighbour-joining algorithms with bootstrap replicates consistently inferred S. baturini as a sister taxon to Trichinellida. Inclusion of S. baturini had a stabilising affect on the integrity of the Dorylaimia clade through breaking the long branch leading to Trichinellida. Puta- tive molecular synapomorphies reconstructed by parsi- mony for each node of the tree were analysed on a large dataset of metazoan SSU rDNA sequences to sort out 178 Nematology</p>
<p>Poster sessions homoplasious characters that may potentially bias par- simony estimations. Strong synapomorphies located in highly conserved parts of the gene support monophyly of all Dorylaimia and suggest the following internal bi- furcation pattern: ((Trichinellida: Dioctophymida): (Do- rylaimida (Mononchida: Mermithida))). Molecular phy- logeny of Dorylaimia juxtaposed with morphologicalevi- dence may alter our perception of morphologicaland eco- logical change in nematode evolution. 161 Phylogeny of Enoplia: parsimony estimations with SSU rDNA sequence data L. R OUSSINE 1 ; ¤ , P. D E L EY 2 , V.V. A LESHIN 1 , J.R. V ANFLETEREN 3 , D. S TURHAN 4 , A. V IERSTRAETE 5 and M. B LAXTER 6 1 Belozersky Institute of Physico-Chemical Biology, Department of Evolutionary Biochemistry, Moscow State University, 119899 Moscow, Russia 2 Department of Nematology, University of California, Riverside, CA 92521, USA 3 University of Ghent, Department of Biology, B-9000 Gent, Belgium 4 Biologische Bundesanstalt, Institut fuer Nematologie und Wirbeltierkunde, 48161 Muenster, Germany 5 University of Ghent, Department of Biology, B-9000 Gent, Belgium 6 Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh, EH9 3JT, UK ¤ roussine@yandex.ru Molecular analyses suggest that Enoplia is the most diver- gent major clade within the phylum Nematoda. Dispari- ties in rates of sequence evolution between lineages, lack of intermediate taxa to break possible long branches and the limited amount of phylogenetic information shared by sampled taxa make phylogenetic inference for Eno- plia a dif cult task. The dataset was carefully selected to maximally encompass enoplian biodiversity and utilise basal representatives of other clades, thus breaking long branches at all levels of the tree. It includes several ge- nera for which molecular evidence has not been previ- ously published: Campydora , Leptosomatum, Thoracos- tomopsis, Bathylaimus, Tripyloides, Calyptronema, Vis- cosia, Halalaimus, Ironus, Alaimus, Xenella, Rhabdode- mania, Tobrilus, Aporcelaimellus and Nygolaimus . The data was examined for presence of phylogeneticsignal us- ing approaches based on sequential removal of categories of variable sites, with phylogeny reconstruction at each step. This case study proves that the NJ method performs highly inconsistently with this problematic dataset and that bootstrap analyses (both NJ and MP) greatly under- estimate repeatability of inferring even basal nodes of the nematode tree. Instead, comparing equally parsimonious topologies obtained in a series of MP runs with a num- ber of statistical tests under the ML optimality criterion allowed the reconstruction of the major lineages within Enoplia. 162 Are data from the beta-tubulin gene family useful for cyst nematode phylogeny? Aniko S ABO ¤ and V.R. F ERRIS Department of Entomology, Purdue University, West Lafayette, IN 47907-1158, USA ¤ anisabo@purdue.edu Many eukaryotic genes have been found to be members of gene families. When similar, but different members of a gene family are recovered with the same PCR primers, it can be dif cult to use such data for phylogenetic inference. To do so, we rst inferred evolutionary relationships among 24 species of cyst nematodes from ribosomal DNA (rDNA) sequence data. Separately, we used beta-tubulin data, now known to be a gene family of six members in Caenorhabditis elegans . Topologies from the two trees were incongruent.Following restriction and hybridisationanalysis, we concluded that beta-tubulin is a small gene family in cyst nematodes as well. We attributed six monophyletic groups on our beta-tubulin tree to putative gene family members. Some taxa appeared in more than one group, indicating the presence of multiple family members. The evolution of the gene family was assessed by tracing putative beta-tubulin genes on the rDNA tree, which we hypothesised to be a true species tree. A reasonable evolutionary scenario could be devised involving gene duplication, gene loss, and deep coalescence. Each of three different groups in Heteroderidae, monophyletic on our species tree, had different putative beta-tubulingene members, and the data therefore corroborated the rDNA species tree. 163 RAPD of Pratylenchus populations from coffee, banana, ornamental plant and citrus in Brazil Silvia Renata S ICILIANO -W ILCKEN 1 ; ¤ , Mário M. I NOMOTO 2 , Luiz Carlos C.B. F ERRAZ 2 , Cláudio M.G. O LIVEIRA 3 and Edson S. M ORI 1 1 FCA/UNESP, P.O. Box 237, 18603-970, Botucatu, SP, Brazil Vol. 4(2), 2002 179</p>
<p>Evolution, phylogeny and classication (123-175) 2 ESALQ/USP, Piracicaba, SP, Brazil 3 Instituto Biológico, Campinas, SP, Brazil ¤ srenata@fca.unesp.br RAPD analyses of seven Pratylenchus populations from different hosts and regions of Brazil identi ed as Pratylenchus coffeae were studied. Three populations were extracted from roots of banana plant (Minas Gerais State), two from citrus (São Paulo State), one from coffee (São Paulo State) and one from Aglaonema (Rio de Janeiro State). Pratylenchus penetrans from oil palm was used as out group. They had been cultured on alfalfa callus tissues. Baermann extracted specimens of the populations from callus were smashed individually into a 200 ¹ l thermocycler tube with 5 ¹ l of lyses buffer and frozen at ¡ 20 ± C. After freezing for at least 1 week, the individuals of each population were pooled, and 5 ¹ l of the bulk of the population was used for PCR ampli cation. They were then run in 3% agarose gel for 3 h at 80 V. The gel was submitted in an ethidium bromite 0.25% and photographed. Polimorphic bands were analysed in Popgene software which grouped them in four clusters according to the host plants. 164 Utility of the heat shock protein gene, hsp90, for phylogenetic analysis and diagnostics of nematodes at several taxonomic levels Andrea M. S KANTAR ¤ and Lynn K. C ARTA USDA-ARS, Plant Sciences Institute, Nematology Laboratory, 10300 Baltimore Blvd, Bldg 011A BARC West, Rm 165B, Beltsville, MD 20705, USA ¤ skantara@ba.ars.usda.gov Novel molecular traits are needed for nematode phy- logeny and diagnostics, particularly when source speci- mens are limited or when currently used molecules do not provide enough molecular discrimination to distin- guish genera, species, or isolates. We have examined the hsp90 gene as a single-copy diagnostic molecule for ne- matodes at several taxonomic levels. We used degener- ate primer PCR to amplify partial hsp90 genomic se- quences from a broad range of bacterial-feeding and plant-parasitic nematode genera. Genomic DNA align- ments showed that hsp90 introns had species-speci c arrangements and genus-speci c sizes. HSP90 amino acid phylogeny revealed several nematode-speci c residues, and placed nematodes paraphyletic to insects. These re- sults demonstrate that hsp90 is informative and useful for evaluating the evolutionary relationships within and between nematodes and other organisms. We performed another study to detect the presence of hsp90 polymor- phisms that may be useful for discrimination of nema- todes at the sub-species level. Comparison of hsp90 ge- nomic sequences from several highly inbred strains of the soybean cyst nematode, Heterodera glycines, revealed unique combinations of intron polymorphisms in some strains, thus demonstrating the potential of this gene for discrimination of soybean cyst nematode genotypes. 165 Functional analysis of heat shock protein, HSP90, from the soybean cyst nematode, Heterodera glycines Andrea M. S KANTAR ¤ , Keli A GAMA and Lynn K. C ARTA USDA-ARS, Plant Sciences Institute, Nematology Laboratory, 10300 Baltimore Blvd, Bldg 011A BARC West, Rm 165B, Beltsville, MD 20705, USA ¤ skantara@ba.ars.usda.gov Developmentally arrested second-stage juveniles of many plant parasites are functionally similar to Caenorhabditis elegans dauers, and likely use molecules similar to those de ned by the C. elegans dauer pathway to regulate developmental arrest, lifespan, and chemosensation. One C. elegans dauer pathway gene, daf-21 , encodes an HSP90 molecular chaperone. The precise function of daf- 21 is unclear; however, HSP90 chaperones are known to refold denatured or misfolded proteins, especially under conditions of stress. In many systems, HSP90 guides the proper folding of speci c target proteins, including nuclear hormone receptors and protein kinases. We are currently examining the effect of an HSP90 inhibitor, geldanamycin, on C. elegans development. Disruption of normal development by this compound would implicate a role for HSP90 in this process, and form the basis for similar studies in plant-parasitic nematodes. We have also initiated a yeast two hybrid screen using Heterodera glycines HSP90 as bait, to identify co-chaperones or target proteins, some of which may include dauer pathway homologs that are critical to plant-parasitic nematode development. In the absence of robust transformation or RNAi strategies for plant-parasitic nematodes, the yeast two hybrid approach should provide a tractable system for analysing gene function and identifying critical protein- protein interactions. 180 Nematology</p>
<p>Poster sessions 166 Phylogenetic and sequence analysis of ITS1, 5.8S gene, and ITS2 regions of the rDNA of Steinernema : comparison of populations and species S.E. S PIRIDONOV 1 ; ¤ , A.P. R EID 2 , K. P ODRUCKA 2 , S.A. S UBBOTIN 1 and M. M OENS 3 1 Institute of Parasitology of RAS, Leninskii prospect 33, Moscow, 117071, Russia 2 CABI-Bioscience, Egham, TW20 9TY, UK 3 Crop Protection Department, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ spiridon@rjnem.msk.ru Ninety new and 16 known complete ITS1 C 5.8S C ITS2 of rDNA sequences belonging to various popula- tions of 22 nominal and several unidenti ed Stei- nernema species have been analysed using maximum parsimony and maximum likelihood methods. Analy- ses showed that more than 90% of the studied se- quences formed four main moderately or highly sup- ported clades ‘ intermedium - af ne ’, ‘ carpocapsae-tami- siamkayai-scapterisci ’, ‘ feltiae-kraussei-oregonense ’, ‘ glaseri-cubanum - arenarium-karii-longicaudum ’) and one weakly supported clade (‘ bicornutum-ceratophorum- riobrave ’). This grouping was obtained in most of the phylogenetictrees obtained from different ITS alignments and phylogeneticprocedures. A short morphologicalchar- acterisation of these clades based on infective juvenile (IJ) body length, amoeboid cell and lateral eld structure is given. Groupings of species in the ITS based trees are largely congruent with previous D2-D3 based trees. Mole- cular analysis revealed at least ten new species among studied Steinernema isolates and proved the identity for two undescribed new species from Germany (types ‘B’ and ‘F’) with British undescribed cultures (types ‘B3’ and ‘D1’), respectively. Sequence differences between more than ten isolates of S. feltiae and S. kraussei were estimated. Several isolates from Switzerland, Sri-Lanka, Venezuela, Vietnam and USA with long and medium- sized IJ were found to be independentfrom related known species. 167 Molecular phylogenies of plant and entomoparasitic nematodes: congruence and incongruence with morphological and biological data Sergei S UBBOTIN 1 ; ¤ , Dieter S TURHAN 2 and Maurice M OENS 3 1 Institute of Parasitology of RAS, Leninskii prospect 33, Moscow, 117071, Russia 2 Biologische Bundesanstalt, Institut für Nematologie und Wirbeltierkunde, Toppheideweg 88, 48161, Münster, Germany 3 Crop Protection Department, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ s.subbotin@clo.fgov.be One of the exciting developments in nematology during the last years has been the application of nucleic acid data analysis to problems of systematics of certain groups. In many cases, molecular data con rm the monophyly of species groups recognised by morphological studies. In other cases, the molecular data reveal taxa of which the phylogenetic relationship based on the morphology seems to be problematic. Molecular data put more light on problems of species boundaries and co-evolution of nematodes with their hosts. The early presumption that phylogenetic trees based on molecular data would more precisely re ect the true phylogeny than morphological data, seems to be wrong. Analyses of in uence of alignment or tree building methods on phylogenies showed that molecular data could be subjected to many problems. Congruence and incongruence of results of analyses of molecular and morphological data sets and the possible reasons for con icts are discussed with examples of plant-parasitic nematodes from the family Heteroderidae, Anguinidae, Longidoridae, and entomoparasitic nematodes of the Tylenchida and the families Steinernematidae and Heterorhabditidae. 168 Molecular phylogenetics of the cyst-forming nematodes (Tylenchida: Heteroderidae) Sergei A. S UBBOTIN 1 ; ¤ , Dieter S TURHAN 2 and Maurice M OENS 3 1 Institute of Parasitology of RAS, Leninskii prospect 33, Moscow, 117071, Russia 2 Biologische Bundesanstalt, Institut für Nematologie und Wirbeltierkunde, Toppheideweg 88, 48161, Münster, Germany 3 Crop Protection Department, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ s.subbotin@clo.fgov.be Sequences of the complete ITS and the D2-D3 expan- sion segment of the 28S gene of rDNA obtained from 54 valid and seven undescribed species of cyst forming nematodes from the genera Afenestrata, Betulodera, Cac- todera , Dolichodera, Globodera, Heterodera and Punc- todera have been analysed using maximum parsimony. On the phylogenetic trees the species clustered in sev- eral major clades corresponding to the morphological grouping and present taxonomic division. The analy- Vol. 4(2), 2002 181</p>
<p>Evolution, phylogeny and classication (123-175) sis yielded six main morphological groups within the genus Heterodera : Avenae, Sacchari, Humuli, Schachtii, Cyperi and Goettingiana. Phylogenetic relationships be- tween some of the Heterodera groups were not well re- solved. The Goettingiana group occupied a basal posi- tion within Heteroderinae. Molecular data strongly sup- ported monophylyof the Punctoderinae containingthe ge- nera Cactodera, Globodera, Punctodera , Betulodera and Dolichodera. Punctodera and Dolichodera have sister re- lationships. Analysis of the D2-D3 expansion segment of the 28S gene only partly resolved relationships within basal groups of Heteroderidae. 169 Phylogenetic relationships within the stem and gall forming plant-parasitic nematodes (Tylenchida: Anguinidae) as inferred from analyses of the ITS-rDNA sequences Sergei A. S UBBOTIN 1 ; ¤ , Eino L. K RALL 2 , Ian T. R ILEY 3 , Vladimir N. C HIZHOV 4 , Ariane S TAELENS 5 , Marc D E L OOSE 5 and Maurice M OENS 6 1 Institute of Parasitology of RAS, Leninskii prospect 33, Moscow, 117071, Russia 2 Institute of Plant Protection, Estonian Agricultural University, 51014 Tartu, Estonia 3 Applied and Molecular Ecology, Adelaide University, PMB1, Glen Osmond, SA 5064, Australia 4 Prospect Mira 184-1-53, Moscow, 129301, Russia 5 Department of Plant Genetics and Breeding, Agricultural Research Centre, Caritasstraat 21, 9090 Melle, Belgium 6 Crop Protection Department, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ s.subbotin@clo.fgov.be Internal transcribed spacer (ITS) sequences of rDNA from 53 populations and species of gall-forming nematodes of the subfamily Anguininae, along with ve populations of the Ditylenchus dipsaci species complex were used for phylogenetic analyses. The molecular analyses support a concept of narrow specialisation for seed-gall nematodes and reveal distinction of at least nine undescribed species of Anguina inducing seed galls, previously identi ed as A. agrostis, and two species within the D. dipsaci species complex. Both the maximum parsimony and maximum likelihood analyses of the ITS data strongly support monophyly of the genus Anguina. Also, non- monophyly for Subanguina in the broad sense of Brzeski (1981) and of Mesoanguina and Heteroanguina according to Chizhov and Subbotin was indicated. Morphological and biological characters are congruent with the anguinid groups supported by the ITS phylogeny. The test of topologies conducted by maximum likelihood analyses shows that the monophyletic origin of anguinids parasitising grasses and sedges could not be rejected. The main anguinid groups are generally associated with plant hosts belonging to the same or related systematic groups. 170 A new anguinid from dune grass in South Africa A. S WART 1 ; ¤ , S.A. S UBBOTIN 2 , L.R. T IEDT 3 and I.T. R ILEY 4 1 Biosystematics Division, Plant Protection Research Institute, Private Bag X134, Pretoria 0001, Republic of South Africa 2 Institute for Parasitology, Russian Academy of Sciences, Leninskii prospect 33, Moscow 117071, Russia 3 Laboratory for Electron Microscopy, Potchefstroom University for CHE, Private Bag X6001, Potchefstroom, 2520, Republic of South Africa 4 Applied and Molecular Ecology, Adelaide University, PMB 1, Glen Osmond, SA 5064, Australia ¤ rietas@plant2.agric.za In October 2000, the senior author received dune grass ( Ehrharta villosa var. villosa ) with purple coloured galls on the stems and leaf sheaths. On opening, each gall contained four to six adult anguinid nematodes and numerous eggs and juveniles. Some galls were lled with a yellow substance containing bacteria. The bacteria were isolated and provisionally identi ed as Clavibacter . The galls and the nematodes were studied with the aid of the scanning electron microscope, the results of which are depicted on the poster. Molecular analysis of the anguinids showed that they are close to both Anguina australis and A. microlaenia . Both these species have been identi ed in Australia where they infect plants of the Poaceae, tribe Ehrharteae. According to molecular analysis, a host test and a light microscope study, the anguinid population from South Africa is new to science and in the process of being described. 171 Phylogenetic analysis of Longidorus and Xiphinema species (Nematoda: Dorylaimida) using ITS1 sequences of nuclear ribosomal DNA Weimin Y E 1 , R.T. R OBBINS 1 and A.L. S ZALANSKI 2 1 Cralley-Warren Center, 2601 N. Young Avenue, Fayetteville, AR 72704, USA 182 Nematology</p>
<p>Poster sessions 2 Department of Entomology, University of Arkansas, Fayetteville, AR 72704, USA Some Longidoridae in the genera Longidorus and Xiphinema are important plant parasites as well as vectors of plant nepoviruses. Species discrimination based entirely on morphology is often questionable and controversial because of morphometric overlap and the lack of a phylogenetic framework for this group. Phylogenetic analysis using DNA sequencing of nuclear ribosomal DNA ITS1 was conducted to construct an evolutionary tree. Extensive interspecies sequence variation and minor intraspecies sequence variation were observed. The analyses suggest two groups within Arkansas Longidoridae species. The Xiphinema group includes X. americanum , X. bakeri , X. chambersi , and Longidorus diadecturus . Longidorus diadecturus shares some morphological characters of both Xiphinema and Longidorus . The Longidorus group includes L. breviannulatus , L. crassus , L. fragilis , ve undescribed species, and two non-Arkansas species ( L. elongatus from Europe and L. africanus from California). The phylogenetic analysis largely corresponded to the genera and species de ned by morphology.Results demonstrated the potential for the use of rDNA ITS1 and 18S gene to infer phylogenetic relationships and PCR-RFLP based identi cation among longidorids. 172 Inter- and intra-speci c variation in ribosomal DNA in some isolates of Bursaphelenchus xylophilus and B. mucronatus Jingwu Z HENG 1 ; ¤ , Sergei A. S UBBOTIN 2 , Shuishan H E 3 , Jianfeng G U 3 and Maurice M OENS 4 1 Department of Plant Protection, College of Agriculture and Biotechnology, Zhejiang University, Hangzhu 310029, China 2 Institute of Parasitology of Russian Academy of Sciences, Leninskii Prospect 33, Moscow 117071, Russia 3 Ningbo Entry-Exit Inspection and Quarantine Bureau, 144 Liu Ting Street, Ningbo 315012, China 4 Crop Protection Department, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ jwzheng@zju.edu.cn The genetic diversity of ve isolates of Bursaphelenchus xylophilus and four of B. mucronatus from China or detected in package woods from Japan and Korea was studied. PCR-RFLP analysis of the ITS region of rDNA showed that AluI , CfoI , HaeIII , HinfI and MspI yield speci c patterns. Using these patterns, both species were detected in a sample from Ningbo, Zhejiang, China. The analysis of the ITS sequence alignment of the four populations of B. mucronatus and of three of the B. xylophilus populations revealed minimal (one nucleotide) intra-speci c divergence. The inter-speci c divergence was more than 100 bp. There were only 3 bp differences within populations of the same species, and 18 or 19 bp difference between species in sequences of the D2 and D3 expansion segments of the 28S gene. 173 Study of populations of Ditylenchus dipsaci from the Czech Republic by molecular methods Miloslav Z OUHAR ¤ and Pavel R YSANEK Department of Plant Protection, Czech University of Agriculture, Kamycka 129, Prague, 165 21, Czech Republic ¤ zouhar@af.czu.cz Ditylenchus dipsaci is one of the most harmful parasitic nematodes in Central Europe. It is able to survive for a long time in soil without its host plants and that is why it belongs among organisms with quarantine importance. Nothing is known about D. dipsaci distribution in the Czech Republic. The aim of the study was to collect samples of D. dipsaci from the Czech Republic and to identify them by molecular methods. A region of rDNA including 3 0 end of S18 gene, ITS1, 5,8S gene, ITS2 and 5 0 end of S26 gene was ampli ed using general primers designed according to the DNA sequence of Caenorhabditis elegans . The amplicon (900 bp) was analysed by RFLP and SSCP. Restriction endonucleases Eco R1, Hinc II and Alu I can be used for differentiation of certain bioraces of D. dipsaci . At the same time, methods for DNA extraction from plant material and contaminated soil were optimised. 174 Study of populations of Globodera rostochiensis and G. pallida from the Czech Republic by molecular methods Miloslav Z OUHAR ¤ and Pavel R YSANEK Department of Plant Protection, Czech University of Agriculture, Kamycka 129, Prague, 165 21, Czech Republic ¤ zouhar@af.czu.cz Potato cyst nematodes (PCN) are organisms of quarantine importance. That is why speci c and sensitive methods for their determination are needed. According to the inter- national classi cation, ve pathotypes of G. rostochiensis and three pathotypes of G. pallida exist. They can be dif- ferentiated by biological tests using potato varieties resis- Vol. 4(2), 2002 183</p>
<p>Evolution, phylogeny and classication (123-175) tant to certain pathotype(s), but this method is time and labour consuming. For the application of molecular meth- ods for species and pathotype differentiation, we used a relatively stable region in the genome of nematodes be- tween genes S18 and S26 with the aim of nding poly- morphisms enabling differentiation of PCN populations from the Czech Republic. Samples of PCN from different localities were tested by PCR, RAPD, RFLP and SSCP. Complete pathotype series from Scotland and Germany were used as standards. Six populationscontained G. pal- lida. These results were identical to the results of biologi- cal tests and morphometrical observations of cysts. 175 An actual and modern identi cation key of the dorylaimid genera world-wide Aldo Z ULLINI 1 ; ¤ and Klemens E KSCHMITT 2 1 Università di Milano-Bicocca, Dipartimento Biotecnologia e Bioscienze, Piazza della Scienza 2, I – 20126 Milano, Italy 2 Justus Liebig University, IFZ – Department of Animal Ecology, H.-Buff-Ring 26-32, D – 35392 Giessen, Germany ¤ aldo.zullini@unimib.it The poster introduces a new key of the dorylaimid genera of the world, updated to the latest taxonomic information available in spring 2002. The key comprises 234 genera, which are differentiated on the basis of nine characters and eight measures. The key is implementedas a graphics- based decision table in electronic form and is targetedly designed for rapid routine identi cation. Response time is as low as 100 ms, full identi cation (99% certainty) is achieved after eight mouse-clicks on average. Because the utilised inference mechanisms consistently rely on probabilistic calculations, the key offers innovative functionality: like other electronic keys it allows for i ) a free sequence of identi cation decisions, ii ) the omission of decisions, and iii ) continuous feedback on identi cation progress. In addition, the key dynamically iv ) indicates the best decision sequence onward, based on the previous selections made by the user, v ) provides a quantitative certi cation of identi cation quality, and vi ) enables nematode classi cation into feeding types and c-p classes prior to full identi cation, whenever possible. The poster explains and illustrates major characteristics of the key. 184 Nematology</p>
<p>Poster sessions 176 Molecular surveys of marine nematode diversity Mark B LAXTER , Ingrid I REDALE , Ronan R OCHE , Robin F LOYD and Abebe E YUALEM Institute of Cell, Animal and Population Biology, University of Edinburgh, Ashworth, Laboratories, Kings Buildings, Edinburgh, EH9 3JT, UK Using the molecular barcoding system developed for ter- restrial nematodes, we performed a set of assays on ma- rine samples to prove the utility of the method in addi- tional habitats. The method relies on polymerase chain ampli cation and DNA sequencing of an informative segment of the small subunit ribosomal RNA (SSUr- RNA) gene from individual nematodes. The sequence is then used to de ne operational taxonomic units (OTU) for the study population, and is compared to sequences from known taxa to attach taxonomic and ecological at- tributes. We surveyed nematodes from the low tide zone of three Scottish beaches (Loch Fyne (West coast, muds), Orkney (Northern, sandy) and Gullane (East coast, estuar- ine/sandy)). A second survey of a gas seep site in the Firth of Forth was carried out to assess the utility of the method for shorter range surveys. Over 250 sequences were de- termined and these de ne over 30 OTU. The molecular OTU identi ed were assigned to ‘morphological’OTU by i ) sequencing from specimens from the sites (identi ed in collaboration with Dr Tim Ferrero and Prof. J. Lamb- shead, NHM, London) and ii ) by comparison to our grow- ing database of nematode SSUrRNA sequences. 177 Free-living marine nematodes in two stations from Diego Perez Key, Cuba E. C ALVO ¤ and J. G UERRA Dpto Biología Animal y Humana, Facultad de Biología, Universidad de La Habana, Calle 25 No. 455 entre J e I, Vedado, Ciudad de La Habana, Cuba ¤ ecalvo@fbio.uh.cu Free-living marine nematodes have been poorly studied in Cuba and, in general, they are named to class level as components of the meiobenthos. The sediment accumulated in the external slope of the reef (Station 1) and among the roots of the red mangrove in the interior lagoon of the key (Station 2) was collected. The temperature and salinity values were 29 ± C and 34%, respectively. Granulometric composition of the stations was analysed. Diversity (H 0 ), evenness (J 0 ) and richness were calculated. One species, 13 genera and 13 families belonging to six orders were identi ed. Station 2 registered not only the highest density of nematodes (658 ind./10 cm 2 ) but also the highest number of families. Monhysteridae, Oncholaimidae and Desmodoridae predominated,and they represented 80.8% of all nematodes in this station. Station 1 was represented by only seven families with a density of 278 ind./10 cm 2 , Desmodoridae being the dominant. The differences found in density, evenness and richness depend on the differential behaviour of the ecological factors. In this sense, stability and granulometric composition of sediments were important. 178 Trophic composition of free-living marine nematodes in two stations from Diego Perez Key, Cuba E. C ALVO ¤ and J. G UERRA Dpto. Biología Animal y Humana, Facultad de Biología, Universidad de La Habana, Calle 25 No. 455 entre J e I, Vedado, Ciudad de La Habana, Cuba ¤ ecalvo@fbio.uh.cu Free-living marine nematodes are ecologically very heterogeneous and occupy different trophic positions in the benthic food web, but in Cuba they are poorly studied. Sediment was collected at the external side of the reef (Station 1) and from among the roots of red mangrove in the interior lagoon of the key (Station 2). Diversity (H 0 ), evenness (J 0 ) and richness were calculated. Nematodes were divided into four trophic guilds: deposit feeders (DF), epistrate feeders (EF), scavengers (S) and predators (P). Trophic behaviour at guild level re ected high differences among stations. The diversity in the guilds was higher in Station 2: this behaviour is due to the distribution of individuals by family, more than the amount of represented families in the case of EF, S and P guilds. The component that produces a higher diversity in DF guild is the amount of families. In DF guild the abundance and richness presented the highest differences between habitats. In Station 2, the two main families are included in two guilds associated with the detritus chain, but in Station 1 the two dominant families are in the same guild related to the grazing chain. 179 Biology and taxonomic notes on sibling species of Oncholaimium (Nematoda: Enoplida) from Russian Far Eastern part of the Sea of Japan Vol. 4(2), 2002 185</p>
<p>Marine and fresh water nematodes (176-186) N.P. F ADEEVA Far East State University, 8 Sukhanova St., 690600 Vladivostok, Russia vfadeev@mail.primorye.ru Species of the marine nematode genus Oncholaimium are widely distributed in the benthos of the Sea of Japan. We determined that the Oncholaimium complex from Russian Far Eastern part of the Sea of Japan was composed of at least three sibling species: O. olium, O. paraolium and O. ramosum. Populations from habitats in three localities have been compared. These three species are very similar in morphology. Multivariate analyses were done for 14 morphometric characteristics in males, and 13 in females. In addition, a series of minor variations in morphology were found (structure of terminal parts of the tubular organ, form of supplementary organ). The sympatric sibling species Oncholaimium complex form a series on the successional scale between the most perturbed conditions occupied by nematode O. ramosum, and less impacted, slightly more predictable and stable conditions, characterised by sub-littoral nematode O. paraolium and by littoral nematode O. paraolium. Detailed eld studies of O. ramosum have found that it is a dominant member of the epifauna in areas subjected to severe organic disturbance and heavy metal and petroleum hydrocarbon contamination,and has the ability to withstand high levels of H 2 S, a combination facilitating the primary opportunist role of this species of the complex. 180 Free-living marine nematode communities in the northern part of Tatarskyi Strait in the Sea of Japan N.P. F ADEEVA ¤ and N.L. D EMCHENKO Far East State University, 8 Sukhanova St, 690600 Vladivostok, Russia ¤ vfadeev@mail.primorye.ru The northwestern part of the Sea of Japan, especially in the region of Amurskyi Liman, is the most productive and sensitive to modern negative anthropogenic activity. Meiofauna were sampled in shallow (3-20 m) continen- tal shelf at 15 stations on June to August 2001. Total meiofauna abundances ranged from three to 1730 indi- viduals per 10 cm 2 with a mean of 810 individuals per 10 cm 2 . In meiobenthos we see reinforced nematodes dominance comparative with other groups. Nematofauna abundances ranged from two to 1350 individuals per 10 cm 2 with a mean of 700 individualsper 10 cm 2 . A total of 46 nematode species were recorded; the most numerous species is widely-distributed Sabatiena pulchra, followed by Anoplostoma cuticularia , Halanonchus arenarius and Tershellingia sp. Nematode communities were identi ed using classi cation and ordination techniques. The identi- ed communities were than characterised with respect to species composition, density, diversity, size structure and feeding type. Deposit feeders were most dominant in all communities, followed by omnivore/predators, explained by the muddy nature of the sediment. The structure of the nematode communities from the Tatarskyi Strait is com- pared with: i ) the communities from adjacent oxic deep sea sediments; ii ) another area of continental shelf water off the coast of Sakhalin; and iii ) shallow reduced envi- ronments such as sediments of eutrophic bottoms in Peter the Great Bay. 181 The embryonic cell lineage of the nematode Pellioditis marina shows evolutionary adaptations towards faster development in the Rhabditidae Wouter H OUTHOOFD ¤ , Sandra V ANGESTEL , Clarinda M ERTENS , August C OOMANS and Gaëtan B ORGONIE University Gent, Department of Biology, K.L. Ledeganckstraat 35, 9000 Gent, Belgium ¤ wouter.houthoofd@rug.ac.be Until now only the embryonic cell lineage of the model or- ganism Caenorhabditis elegans has been described. The complete embryonic cell lineage (until muscle contrac- tion) of a Pellioditis marina embryo was established by means of 4D-microscopy. Pellioditis marina is a close rel- ative of C. elegans , but has adapted to a marine, brackish environment. The overall cell lineage resembles strongly that of C. elegans , with a few small differences. At the stage of muscle contraction (when most cells are estab- lished), P. marina has as many cells as C. elegans (571 cells) but less cell deaths (60 and 106, respectively). In more derived forms of development, like in P. marina and C. elegans , developmental rate is hastened by adapting their lineage, so that cells originate close to their nal position. This could explain the ‘chaotic’ cell lineages of P. marina and C. elegans where tissues are derived from different founder cells. In the slower developing Hali- cephalobus sp., sublineages form identical cells, which migrate to their exact location. Pellioditis marina and C. elegans have adjusted these lineages to avoid these migra- tions and hasten their development. 186 Nematology</p>
<p>Poster sessions 182 Thallassinidean burrow walls: a cradle for nematodes Helmut K OLLER Department of Marine Biology, University Vienna, Altanstrasse 14, A-1010 Wien a9209422@unet.univie.ac.at As a part of a study of the biology of the intertidal- burrowing shrimp Callianassa tyrrhena (Thalassinidea) the meiofauna from burrow walls and chambers was compared with that of surface sediment and embedded ambient debris. Abundance and size spectrum of nematodes from all samples were determined. Nematodes from burrow wall and surface sediment samples were identi ed to genus level. The highest number of nematodes especially juveniles was found in the burrow wall samples. Halaphanolaimus was the most dominant of the 19 different genera found in this sample category. In surface sediment samples 12 different genera were found, with Chromadorina being the most dominant. Seven genera are common to both sample categories. The densely packed sediment of the burrow walls apparently has enough interstitial space for a large meiofauna community, and also represents a retreat for juvenile nematodes. 183 Phylogenetics of marine nematodes – a molecular approach Birgit M ELDAL 1 ; 2 ; ¤ , John L AMBSHEAD 2 , Alex R OGERS 3 , Adam C OOK 2 , Mark B LAXTER 4 , Nicola M ITCHELL 2 and Melanie A USTEN 5 1 School of Ocean and Earth Sciences, University of Southampton, Southampton Oceanography Centre, European Way, Southampton, SO14 3ZH, UK 2 Nematode Research Group, Department of Zoology, The Natural History Museum, London SW7 5BD, UK 3 British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 0ET, UK 4 Institute of Cell, Animal and Population Biology, Ashworth Laboratories, University of Edinburgh, King’s Buildings, West Mains Road, Edinburgh, EH9 3JT, UK 5 Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, PL1 3DH, UK ¤ birgit.meldal@soc.soton.ac.uk Historically, the classi cation of nematodes has been based solely on the interpretation of the evolutionary history of morphological characters, resulting in a set of mutually incompatible systems. Molecular phylogenetics offer the promise of being able to resolve con icts in this eld by measuring relatedness using a single metric and veri able, model-drivenanalysis. Phylogenetic relationships of marine nematodes from UK waters were inferred from partial small subunit ribosomal RNA gene sequences. As part of the experimental design a new sequence of techniques was set up to ensure species identi cation prior to DNA extraction of the whole animal. Phylogenetic trees derived from these sequences showed that, within ‘Adenophorea’, only the Monhysterida form a monophyletic group, and that the Chromadorida and Enoplia are both polyphyletic.Even at higher taxonomic levels, different clusterings of species are evident in molecular compared to morphological phylogenies. The data support earlier studies using molecular techniques in that classical views of nematode systematics have to be revised. 184 Nematodes of the order Dorylaimida (Pearse, 1942) in different high-mountain lakes of the Sierra Nevada (Granada, Spain) A. O CAÑA 1 ; ¤ , R. P EÑA S ANTIAGO 2 , J. H ERNÁNDEZ R UIZ 1 and R. M ORALES B AQUERO 1 1 Depto Biología Animal y Ecología, Universidad de Granada, Granada 18071, Spain 2 Depto Biología Animal, Vegetal y Ecología, Facultad de Ciencias Experimentales, Universidad de Jaén, Jaén 23071, Spain ¤ amelia@ugr.es A total of 20 lakes was sampled in the Sierra Nevada mountains (Granada, Spain) in the summers of 1990 and 1991. At the beginning of this period in 1991, the lakes were still covered with ice. Despite their altitudes of 2820- 3050 m and being oligotrophic lakes, the nematofauna proved abundant. The orders with the greatest total biomass were: Dorylaimus asymphidorus Andrássy, 1969 (45.2% of the total of the dorylaimids in 1990 and 62% in 1991); Mesodorylaimus cf. litoralis Loof, 1969 (35% in 1990 and 7.7% in 1991) and Paractinolaimus macrolaimus Meyl, 1957 (4.5% in 1990 and 14.2% in 1991). No correlation was found between the dorylaimids and the physico-chemical parameters analysed; however, this nematofauna correlated positively with surface area, depth and catchment area of the lakes. 185 Marine nematodes as hosts for chemoautotrophic symbionts Vol. 4(2), 2002 187</p>
<p>Marine and fresh water nematodes (176-186) Joerg O TT 1 ; ¤ , Monika B RIGHT 1 , Andrea N USSBAUMER 1 , Katrina V ANURA 2 , Irmgard E ICHINGER 1 and Irma S CHABUSSOVA 1 1 Institute of Ecology and Conservation Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria 2 Dept. of Internal Medicine I, Div. of Hematology & Hemostaseology, University Hospital/Vienna, Währinger Gürtel 18-20, A-1090 Vienna, Austria ¤ joerg.ott@univie.ac.at Marine free-living nematodes (Stilbonematinae, Desmo- doridae, Adenophorea) have ectosymbiotic sulphur- oxidising chemoautotrophic bacteria attached to their cuticle in a genus or species speci c pattern. In the genus Eubostrichus the bacteria are up to 100 ¹ m long non- septate laments containing many nucleoids. The worms supply the bacteria alternately with oxygen and sulphide by migrating through the chemocline in sheltered sandy sediments. In turn, the bacteria are eaten by the worms and probably constitute their only food. The nematodes possess conspicuous epidermal glandular sense organs which are unique to the Stilbonematine. The mucus produced by these glands is most probably connected to the recognition mechanism between the worms and the bacteria. The latter are shed with each moult and have to be recruited from the environment. Preliminary data suggest a lectine/sugar bond. According to the sequence of the 16S rRNA gene the primary symbionts all belong to the ° -proteobacteria. In addition, the complex bacterial coat of some genera harbours a variety of other bacteria, including ® - and " -proteobacteria and cytophaga. The stilbonematid/bacteria symbiosis is found in tropical to cool temperate shallow waters. Highest diversity and abundance, however, is found in tropical calcareous sediments. 186 Draconema hoonsooi n. sp. and Draconema youngeouni n. sp. (Adenophorea: Chromadorida: Draconematidae). The rst record of free-living marine nematodes from Korea Hyun Soo R HO 1 ; ¤ , Joong-Ki P ARK 1 , Cheon Young C HANG 2 and Won K IM 1 1 School of Biological Sciences, Seoul National University, Seoul 151-747, Korea 2 Department of Biology, College of Natural Sciences, Taegu University, 712-714, Korea ¤ batillipes@hanmail.net Two free-living marine nematodes, Draconema hoonsooi n. sp. and Draconema youngeouni n. sp. of the family Draconematidae, are described on the basis of the specimens sampled at depth 30-60 m of the Sea of Japan and Jeju Island of Korea. Draconema hoonsooi n. sp. is recognised by the possession of the following characteristics: having a cup-shaped amphideal fovea in both male and female, ve pairs of evenly tapered anal setae (male), 15 pairs (male) and 18 pairs (female) of posterior sublateral adhesion tube (SlAT), and ve pairs of setae on non-annulated tail region in both sexes. Draconema youngeouni n. sp. can also be easily distinguished from all known congeneric species in having a combination of the following features: the greater body length and slender body shape, the bowl- shaped amphideal fovea in both male and female, 13 pairs (male) and 17 pairs (female) of posterior sublateral adhesion tube, ve pairs of evenly tapered anal setae (male), and the absence of long setae on non-annulated tail region in both sexes. The photomicrographs of the new species by scanning electron microscopy (SEM) and differential interference contrast (DIC) microscopy are presented with a detailed morphological description. 188 Nematology</p>
<p>Poster sessions 187 Molecular evolution among geographic isolates of Steinernema carpocapsae Byron J. A DAMS ¤ and Khuong B. N GUYEN Entomology and Nematology Department, University of Florida, Gainesville, FL 32611-0620, USA ¤ bjadams@u.edu Ribosomal DNA (ITS regions 1 and 2) from ten disparate geographic isolates of Steinernema carpocapsae was sequenced and analysed in order to better understand intraspeci c variation, speciation, and the molecular evolution of this locus. Taxa assumed to represent panmictic populations were sampled from the USA, Poland, Russia, France, Sweden, UK and Mexico. No phylogeographic patterns emerged from the data set. Among the populations, transitions were as common as transversions, and a single insertion event was observed. Intra-individual polymorphic characters with states xed among other taxa indicate an intermediate phase in concerted evolution and tokogenetic relationships among the sampled taxa. These data are used to explore the mode and tempo of evolution at this locus, and as an operational model for comparing applications of species concepts. 188 Ef cacy of steinernematid nematodes against three insect pests of crucifers in Quebec Guy B ÉLAIR ¤ , Yvon F OURNIER and Nathalie D AUPHINAIS Agriculture and Agri-Food Canada, 430 Gouin Blvd, St-Jean-sur-Richelieu(Quebec), J3B 3E6, Canada ¤ belairg@em.agr.ca Steinernema feltiae , S. carpocapsae and S. riobrave were evaluated against imported cabbageworm Artogeia rapae , diamondback moth Plutella xylostella , and cabbage looper Trichoplusia ni under laboratory and eld conditions.LD 50 values ranged from 3.6-18.2 for A. rapae L2, from 2.3-24.5 for P. xylostella L3, and from 4.7- 10.1 for T. ni L2. S. feltiae UK was the most pathogenic strain on all three pests. Maximum larval mortality rates recorded on A. rapae were in uenced by temperature: 100% with S. riobrave 335 at 30 ± C, 95.8% with S. feltiae UK at 25 ± C, 91.7% with S. feltiae 27 at 25 ± C, and 75.7% with S. carpocapsae All at 30 ± C. Mortality of A. rapae L2 increased with contact time to S. carpocapsae All and S. feltiae UK with a 76 and 78% maximum, respectively, reached after 12 h contact. At 20 ± C and 70% RH, survival rates of S. carpocapsae All, S. feltiae UK, and S. riobrave 335 on cabbage leaves were 43, 2, and 0%, respectively, 4 h following application. Under eld conditions, foliar applications of S. carpocapsae All provided 24.9, 19.4 and 14.9% control of A. rapae on Brussels sprout, broccoli, and cauli ower, respectively. 189 Discrimination between isolates of Heterorhabditis bacteriophora Poinar, 1976 (Nematoda: Heterorhabditidae) from the province of Córdoba, Argentina María A. B ERTOLOTTI 1 ; ¤ , Marcelo E. D OUCET 1 and Julio A. D I R IENZO 2 1 Laboratorio de Nematología, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, C.C. 122, 5000, Córdoba, Argentina 2 Unidad de Procesamiento Electrónico de Datos, Facultad de Ciencias Agropecuarias, (U.N.C.). C.C. 509, 5000, Córdoba, Argentina ¤ mbertolo@gtwing.efn.uncor.edu Up to the present, eight isolates of Heterorhabditis bacteriophora from the province of Córdoba have been described, and signi cant differences have been found for all their morphometrical characters. The aims of this work were: to discriminate these isolates based on morphometrical characters, to identify the principal characters that permit their separation and to evaluate the possible relationship between isolates. Isolates from six departments corresponding to two different phytogeographical regions of the province were considered. Hermaphroditic females, amphimictic females, males and infective juveniles (IJ) were analysed. An evident separation of one isolate with respect to the others was observed in adults. In IJ the isolates were separated in three groups. The most relevant morphometrical characters for discrimination were: distance between anterior end and nerve ring, body diameter at anus, distance between anterior end and excretory pore, ratios a, c, D in adults; distance between anterior end and pharyngeal basal bulb, distance between anterior end and excretory pore, ratios a, D, E in IJ. Similarity relationship among isolates was different depending on the stage considered. 190 The use of the glycosylase-mediated polymorphism detection for the study of gene ow in entomopathogenic nematodes Stephen B OYLE and Thomae K AKOUL I -D UARTE ¤ Vol. 4(2), 2002 189</p>
<p>Entomopathogenic nematodes (187-221) Department of Applied Biology and Chemistry, Institute of Technology Carlow, Kilkenny Road, Carlow, Ireland ¤ thomae.kakouli@itcarlow.ie Entomopathogenic nematodes are traded for control of dif cult pests. The greatest limitation on understanding how indigenouspopulationsare affected by new strains or escaped genes is the problem of recognising the genetic structure of wild populations and the levels of gene ow between them. We are aiming at studying gene ow in Irish entomopathogenic nematode populations by detecting DNA polymorphisms in the intron regions of highly conserved nematode genes. We have used EPIC- PCR to amplify part of the major sperm protein gene from Steinernema feltiae and Heterorhabditis megidis containing a putative intron. DNA sequence analysis will follow to con rm the presence of the intron. Ampli cations were achieved using degenerate primers designed after aligning the major sperm protein sequences from seven nematode species taken from GenBank. Our research is still ongoing for additional suitable genes. Genetic variation in the introns will be studied by the use of the glycosylase-mediated polymorphism detection (GMPD). Introns will be reampli ed using the four dNTPs including uracil and having adjusted the dTTP to dUTP ratio. Products will then be subjected to the action of uracil DNA glycosylase, which results in DNA cleavage at speci c sites thus generating an allelic pro le for each population studied. 191 Life cycle of Gastromermis massei Doucet & Cagnolo, 1997 (Nematoda: Mermithidae) Susana R. C AGNOL O ¤ and Marcelo E. D OUCET Laboratorio de Nematología, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, C.C. 122, 5000 Córdoba, Argentina ¤ scagnolo@gtwing.efn.uncor.edu The life cycle of Gastromermis massei was studied for 3 years. Samples were taken from the bed of Cosquín River, Córdoba, Argentina and individuals in their free-living stage were collected with Surber trap. Samples were processed through suspension and 40 ¹ m pore sieving. Larvae, pupae and adults of Simulium ( Ectemnaspis ) wolfhuegeli (Enderlein) were collected for the study of the parasitic stage. Parasites and immature stages of hosts were kept under laboratory conditions. Cycle was completed in 30-40 days. It includes adults, eggs, and four larval stages. Eggs are deposited freely on the substrate, without showing segmentation. The embryonic development is completed 12-15 days after oviposition at 26 ± C. The pre-parasitic juvenile emerges from the egg, living only 48 h, when it must nd and penetrate the host. The parasitic juvenile develops in the host, being the only feeding stage. The post-parasitic juvenile abandons the host through cuticle perforation. It moults into adult, male or female, in the environment. Moulting, copulation and oviposition were observed only when numerous individuals were interlaced. The biological observations performed agree with what was indicated for other species of the genus Gastromermis . 192 Phoretic association of Steinernema feltiae (Nematoda) with Eisenia fetida (Annelida) Raquel C AMPOS 1 ; ¤ , Jesús J IMÉNEZ 1 , Dolores T RIGO 2 , Marta R AMAJO 2 and Carmen G UTIÉRREZ 1 1 Dpto Agroecología, CCMA CSIC, Serrano 115 dpdo 28006 Madrid, Spain 2 Dpto Biología Animal I, Facultad de Ciencias Biológicas, Universidad Complutense de Madrid, Spain ¤ raquel.campos@ccma.csic.es Earthworms improve soil characteristics and have a no- table in uence on edaphic organisms; however, inter- actions between them have not been studied in detail. After protozoa, nematodes are the most abundant and diverse group of soil invertebrates and an important part of food webs. Entomopathogenic nematodes are an environmentally-friendly alternative for insect pest con- trol. However, their dispersal capability is limited and it is often dif cult to reach the expected level of control. Since earthworms are able to change soil structure and move large amounts of soil, some authors think that earthworms could be used as vectors to introduce and disperse ben- e cial organisms. As part of the study about interactions between earthworms and nematodes, we show the infec- tivity results of Steinernema feltiae after passage through the Eisenia fetida gut. Moreover, entomopathogenic ne- matodes have no deleterious effect on earthworms. 193 Combination of Steinernema carpocapsae (Weiser) and pheromone lure: a promising strategy for biological control of the banana black weevil Cosmopolites sordidus (Germar) on bananas in Martinique C. C HABRIER 1 , H. M AULEON 2 and P. Q UÉNÉHERVÉ 3 1 CIRAD, BP 153, 97202 Fort-de-France Cedex, Martinique 190 Nematology</p>
<p>Poster sessions 2 INRA-URPV, Domaine Duclos, 97170 Petit Bourg, Guadeloupe 3 IRD, BP 8007, 97259 Fort-de-France cedex, Martinique Cosmopolites sordidus (Germar, 1824) is one of the major pest of bananas in the Caribbean. Several techniques can be applied to avoid use of insecticides. On one hand, laboratory studies have shown that some speci c strains of Steinernema spp. could contribute ef ciently to the control of this pest. Unfortunately, eld applications of formulations of S. carpocapsae often give inconsistent results due to formulation and conservation constraints. On the other hand, mass-trapping using pheromone lure has given good eld results, excepted when the C. sordidus population levels were very high. In this study, we used pheromone traps to contaminate weevils with entomopathogenic nematodes instead of killing them. During a 10 month study, we evaluated the interest of pheromone traps using pheromone lure on which we replaced each week new Galleria mellonella larvae previously inoculated with S. carpocapsae (Weiser). In this experiment, promising results were obtained with a reduction of attacked plants from 98.5 to 40% and a reduction of the attack severity (according to Vilardebo’s coef cient) from 42 to 23. 194 Effects of storage temperature on survival, infectivity and lipid content of the entomopathogenic nematode Steinernema feltiae (Rhabditida: Steinernematidae) Shulong C HEN ¤ , Xiuying H AN and Maurice M OENS Agricultural Research Centre, Crop Protection Department, Burg. Van Gansberghelaan 96, B-9820 Merelbeke, Belgium ¤ shulong.chen@rug.ac.be The Belgian Lxm 31 population of Steinernema feltiae was cultured in vitro or in vivo and stored in water at 5, 10, 15 or 20 ± C. Its survival, infectivity and lipid content were evaluated after 0, 0.5, 1, 2, 3, 4, 5, 6, 12 or 18 months. Temperature, storage time and culture method signi cantly in uenced the survival of the infective juveniles (IJ). Survival decreased with increasing storage temperature and was negativelycorrelated to storage time. After a long-term storage, the percentage of surviving IJ was higher when cultured in vivo than when produced in vitro . Storage temperature also in uenced infectivity. When kept at low temperatures (5-10 ± C), IJ infectivity decreased during the rst half month and then increased. When IJ were stored at 20 ± C, their infectivity increased during the rst half month after which it decreased. The lipid content of IJ was negatively correlated to the storage temperature and time. Lipid content and IJ survival were positively correlated; lipid content and IJ infectivity were not correlated. 195 The potential of Heterorhabditis marelatus for control of Colorado potato beetle Nathan C OTTRELL ¤ , E. G RAFIUS and H. M ELAKEBERHAN Michigan State University Department of Entomology, 243 Natural Science Building, East Lansing, MI 48824-1115, USA ¤ cottre19@msu.edu Colorado potato beetle (CPB, Leptinotarsa decemlineata ) is an important pest of potato and has considerable re- sistance to many insecticides. With current and future re- strictions on pesticides, ecologically safe alternatives are needed. The goal of this project is to develop Heterorhab- ditis marelatus ( Hm ) as a biologicalcontrol alternative for CPB through understanding its pathogenicity and adap- tation to eld edaphic factors. Hm had best survival and pathogenicityin sand and sandy loam soil and at 60-100% moisture content under controlled conditions. In naturally CPB infested eld plots (322 m 2 ), treatments of 0, 333 million, 667 million or 1 billion Hm /m 2 of soil in 2000 and 2001 showed higher numbers of beetles in control plots compared with nematode-treated plots. Field cages (2 m 3 ) arti cially infested with ve CPB adults per plant were treated with either 0 or 1 billion Hm /m 2 at the emer- gence and peak of 4 th instar, or at peak pupation. Time of application was not signi cant, but more adults emerged in controls than in Hm treated plots. Overall, the results suggest that Hm has a potential for managing CPB under eld conditions. 196 Abundance of endemic entomopathogenic nematodes following application of Steinernema riobrave L.W. D UNCAN 1 , J.H. G RAHAM 1 , D.C. D UNN 1 , J. Z ELLERS 1 and K. N GUYEN 2 1 University of Florida, Citrus Research and Education Center, 700 Experiment Station Rd., Lake Alfred, FL 33850, USA 2 Department of Entomology and Nematology, Gainesville, FL 32611, USA Caged insect larvae were buried at monthly intervals in a Florida citrus orchard during 2000-2001 to monitor nat- Vol. 4(2), 2002 191</p>
<p>Entomopathogenic nematodes (187-221) ural control of Diaprepes abbreviatus by entomopatho- genic nematodes (EPN). The survey occurred in plots that were treated or not treated with Steinernema riobrave dur- ing 1998-2001. Mean monthly insect mortality in control plots ranged from 13-74% and endemic EPN ( Steiner- nema sp ., Heterorhabditis zealandica, H. indica, and H. bacteriophora ) were recovered from 22-81% of the ca- davers each month. Endemic EPN in each plot were in- versely related to S. riobrave and directly related to the numbers of adult weevils ( D. abbreviatus and Pachnaeus litus ) captured in modi ed Tedders traps. Insect mortality was higher and cadavers containing endemic EPN were more numerous in control plots than in S. riobrave- treated plots, except during months in which S. riobrave was ap- plied. In treated plots, recovery of endemic EPN exceeded that of S. riobrave in all but the treatment months. The net ef cacy of S. riobrave treatments against D. abbrevia- tus attenuated over time, possibly due to competitive dis- placement of EPN that are better adapted than S. riobrave to persist in Florida citrus orchards. 197 Pro tability of applications of Steinernema riobrave , metalaxyl and supplemental fertilisation for management of Diaprepes abbreviatus and Phytophthora nicotianae in a Florida citrus orchard L.W. D UNCAN , J.H. G RAHAM and J. Z ELLERS University of Florida, Citrus Research and Education Center, 700 Experiment Station Rd, Lake Alfred, FL 33850, USA An experiment was conducted (1998-2001) in a central Florida citrus orchard infested by Diaprepes abbreviatus and Pachnaeus litus to evaluate the pro tability of recommended IPM tactics for insect control. Main plots were i ) not treated for insect control, ii ) treated twice annually since 1998 with commercially formulated Steinernema riobrave, or iii ) treated twice annually with S. riobrave and 15 times annually with liquid fertiliser in place of dry fertiliser (three times/year) used in the other treatments. Split plots were untreated or treated twice annually with metalaxyl. Carbaryl was applied once (May 1998) to treatments 2 and 3. During 4 years, numbers of D. abbreviatus in plots were directly related to abundance of Phytophthora nicotianae and inversely related to fruit yield. Fertiliser treatment did not affect yield or abundanceof any pest. Treatment with S. riobrave reduced numbers of both insects and abundance of P. nicotianae by an average of 45-60% annually except in 2001. Metalaxyl did not affect abundance of the fungus. A single treatment of carbaryl followed by 4 years of treatment with S. riobrave increased the cumulative yield (1999-2001) of citrus by 16-23%, a 4-11-fold return on investment, depending on fruit variety and market destination. 198 Liquid culture production of biocontrol nematodes R.-U. E HLERS ¤ and A. P ETERS Institute for Phytopathology, University of Kiel, Department of Biotechnology & Biological Control, Klausdorfer Str. 28-36, 24223 Raisdorf, Germany ¤ ehlers@biotec.uni-kiel.de For mass production nematodes are produced in liquid media pre-incubated with the symbiotic bacterium for 1 day before the dauer juveniles are inoculated. Nematode yields and the process duration can vary signi cantly. Several different species have nowadays been cultured successfully in liquid media. For example, Heterorhabditis megidis dauer juvenile yields can reach 100 000/ml; however, the mean of several processes is usually not higher than 40 000/ml. The process time is either 15 days (one generation) or 24 days (two generation process). Yields depend on the nematode species cultured. Species with smaller dauer juveniles can reach a dauer juvenile density of > 500 000/ml. A major reason for process instability is a variation of the nematode population dynamics. Another in uencing factor on yields is the bioreactor design. Internal loop bioreactors equipped with a marine propeller can provide the necessary oxygen at low shear forces. The system has been proven to be superior to airlift and conventionally stirred bioreactors and has been successfully scaled up to 3000 l. 199 Factors in uencing dauer juvenile recovery of Heterorhabditis bacteriophora in liquid culture R.-U. E HLERS ¤ , J. A UMANN and O. S TRAUCH Institute for Phytopathology, University of Kiel, Department of Biotechnology & Biological Control, Klausdorfer Str. 28-36, 24223 Raisdorf, Germany ¤ ehlers@biotec.uni-kiel.de Recovery is the step of the developmentallyarrested infec- tive third stage juvenile (dauer) to feeding third stage juve- niles, which continue growth to reproductive adults. It is a response to yet unidenti ed food signals, which re ect the nutritionalconditionsin the environment.Unlike dauer ju- 192 Nematology</p>
<p>Poster sessions veniles (DJ) of Caenorhabditis elegans , which recover in the presence of yeast extract, entomopathogenic nematode DJ need more speci c signals. In liquid culture a de ned number of hermaphrodites (approximately 5000/ml in the tested medium) results in maximum yields. This density, however, cannot easily be obtained by just de ning the DJ inoculation density. In liquid culture DJ respond to food signals produced by their symbiotic bacteria, which cause between 18 and 90% of the DJ to recover within a period of several days. This unsynchronised and low recovery in in vitro cultures is the major reason for process instability and variable yields. In order to increase recovery and thus improve the management of nematode populationdensity, several process parameters were investigated for their in- uence of DJ recovery in liquid culture. 200 Effect of the Steinernema feltiae-Xenorhabdus bovienii complex on Meloidogyne javanica D.J. F ALLON 1 , H.K. K AYA 2 and B.S. S IPES 1 ; ¤ 1 Plant and Environmental Protection Sciences, University of Hawaii, Honolulu, HI 96822, USA 2 Department of Nematology, University of California, Davis, CA 95616, USA ¤ sipes@hawaii.edu Metabolites from the Steinernema feltiae – Xenorhabdus bovienii complex were tested for their ef cacy against Meloidogyne javanica penetration and egg production in soybean. In vitro metabolites of X. bovienii were collected from 4-day-old YS-broth cultures by ethyl acetate extraction. In vivo metabolites of the S. feltiae – X. bovienii complex were collected from 4-day-old S. feltiae- infected Galleria mellonella . Daily applications of in vitro exudates at 1 mg/plant/day, or S. feltiae juveniles at 1000 or 10 000 infective juveniles/plant/day, for up to 3 days, were ineffective at reducing M. javanica penetration or egg production, compared to water treatment. A single application of in vivo metabolites applied at 250 mg-insect-cadaver/plant reduced M. javanica penetration by 42% compared to water treatment, but the effect was lost using multiple applications. Daily applications of in vivo metabolites did not affect M. javanica egg production. Multiple treatment applications increased M. javanica establishment in soybeans. Steinernema feltiae – X. bovienii complex effects on M. javanica were highly variable. 201 Thermal adaptation of entomopathogenic nematodes: acclimation, trehalose accumulation, and survival at environmental extremes Parwinder S. G REWAL and Ganpati B. J AGDALE Department of Entomology, Ohio State University, Wooster, OH 44691, USA Cold acclimation leads to trehalose accumulation in entomopathogenic nematodes. We hypothesised that trehalose accumulation in nematodes is a general strategy to prepare for survival at environmental extremes. Therefore, we tested whether the nematodes will accumulate trehalose during acclimation at sub-lethal warm and cold temperatures and whether the accumulated trehalose correlates with enhanced desiccation, heat, and freezing tolerance. Three species, Steinernema carpocapsae, S. feltiae and S. riobrave, were acclimated at 35 and 5 ± C for 1 and 4 days, respectively, and their trehalose contents were measured. Survival of acclimated- and non-acclimated nematodes at ¡ 20 and 40 ± C and in 25% glycerol was compared. Steinernema riobrave and S. carpocapsae accumulated high trehalose at 35 ± C, and S. feltiae at 5 ± C. Heat tolerance in acclimated S. carpocapsae and S. feltiae was high, but unaffected in acclimated S. riobrave . Freezing tolerance in acclimated S. carpocapsae and S. riobrave was increased, whereas in acclimated S. feltiae it was unaffected. Heat acclimated S. carpocapsae and cold acclimated S. riobrave showed the highest desiccation survival at 5 ± C. Overall, the accumulated trehalose levels appear to enhance desiccation, freezing and heat tolerance of entomopathogenic nematodes. 202 Differences in susceptibility of introduced and native white grub species to entomopathogenic nematodes from diverse geographic localities P.S. G REWAL 1 , S.K. G REWAL 1 and M.G. K LEIN 2 1 Department of Entomology, Ohio State University 2 USDA, Agricultural Research Service, Horticultural Insects Research Laboratory, 1680 Madison Avenue, Wooster, OH 44691, USA We compared the susceptibility of the introduced Popillia japonica and the native Cyclocephala borealis to 16 species and strains of entomopathogenic nematodes isolated from within or outside the geographic ranges of the two scarabs. We found large variation in the virulence of the species/strains of nematodes with over Vol. 4(2), 2002 193</p>
<p>Entomopathogenic nematodes (187-221) 50% mortality of P. japonica produced by Heterorhabditis zealandica strain X1 and H. bacteriophora strain GPS11 and of C. borealis by H. zealandica and H. bacteriophora strains KMD10 and NC1. Heterorhabditis indica and H. marelatus caused less than 20% mortality of both scarab species. When considered as a group, the nematode species and strains from within and outside the geographic ranges of either P. japonica or C. borealis did not differ in virulence towards either scarab species. Results suggest that the introduction of the exotic H. zealandica into the front-line states with respect to the movement of P. japonica and A. orientalis should be explored as a tactic to delay their establishment and spread. The results also suggest that the manipulation of the indigenous H. bacteriophora populations may help in delaying spread and mitigating losses caused by the invasive grub species. 203 Control of overwintering black vine weevil Otiorhynchus sulcatus by a cold-active entomopathogenic nematode Steinernema kraussei Andrew J. H ART ¤ and Deena M. W ILLMOTT Department of Entomological Sciences, Horticulture Research International, Wellesbourne, Warwick CV35 9EF, UK ¤ andrew.hart@hri.ac.uk The susceptibility of black vine weevil larvae Otiorhyn- chus sulcatus to a cold-active entomopathogenic nema- tode, Steinernema kraussei (isolate L137) and a commer- cially available nematode, Steinernema carpocapsae (Ex- hibit) was compared in winter eld trials. Nematodes were applied to outdoor potted strawberry plants at a range of doses in early winter. Parasitism and mortality of vine weevils were assessed at the end of the winter experiment. Up to 83% of vine weevils were infected and killed by S. kraussei at the high dose of 60 000 nematodes per pot, whereas treatments with S. carpocapsae caused no signi - cant mortality. S. kraussei (L137) was able to survive win- ter eld conditions including prolonged exposure to low temperatures in contrast to S. carpocapsae which showed poor survival. These results suggest S. kraussei (L137) has great potential as a commercial biocontrol agent against overwintering O. sulcatus . 204 Effect of soil texture on Steinernema feltiae (Filipjev) virulence against Spodoptera littoralis (Lepidoptera: Noctuidae) Jesús J IMÉNEZ , Raquel C AMPOS and Carmen G UTIÉRREZ ¤ Dpto Agroecología, CCMA CSIC, Serrano 115 dpdo 28006 Madrid, Spain ¤ carmen.g@ccma.csic.es Spodoptera littoralis , a serious pest in African and Mediterranean countries, has highly polyphagous larvae, which feed mainly at night and hide below ground by day. Pupation takes place just below the surface of the soil, and there are at least seven generations a year in warm climates. Although chemical pesticides and Bt are used for control, resistances have recently been reported in eld and laboratory. Entomopathogenic nematodes are virulent against many species of insects. Their ability to actively locate and kill an insect host in a few hours as well as their high reproductive potential and capacity for mass production make these organisms a key to establishing environmentally-friendly alternatives for controlling insect pests. However, their dispersal capability in soil can be affected by the texture and biological factors of the isolation strain. Thus, soil texture/infectivity bioassays can improve on selection of a more accurate eld dose application. The virulence of Steinernema feltiae (Rioja strain) against S. littoralis in three soils with different clay contents was studied under laboratory conditions. Replicate samples of various doses of S. feltiae juveniles were applied to the soil surface. Nematode virulence against S. littoralis was reduced in soil with 24% clay content. 205 The genetic selection for improved desiccation tolerance of Heterorhabditis megidis 01 PL Jolanta K OWALSKA ¤ Institute of Plant Protection, Miczurina Str 20, 60-318 Poznan, Poland ¤ J.Kowalska@ior.poznan.pl The process of selection was induced in a Polish isolate of Heterorhabditis megidis (01 PL). The objective of the selection procedure was to improve the nematode desic- cation tolerance in extreme environmental conditions. A series of base populations, 10 000 infective juveniles (IJ) each, was exposed to environments with reduced relative humidity (r.h.) levels in order to establish the threshold of 30% survival after 24 h. The experiments were con- ducted in desiccators with various saturated salt solutions at 20 § 1 ± C. The initial r.h. level for the selection was set at 60%. After each round the selected nematodes were repro- duced in last instar larvae of Galleria mellonella . Evalua- 194 Nematology</p>
<p>Poster sessions tion of the selection ef cacy was based on the nematode survival after each round. Although the selection is still in progress, overall changes in the population survival at low humidity levels are observed. This trial was to assess the possibilityof permanent enhancementof the nematode desiccation tolerance although the genetic determination of this characteristic still remains unknown. It is planned to continue the research in the future. The survival and pest control ef cacy of the selected nematode population when exposed to open- eld conditions will be tested. 206 Identifying nematode-inducible genes in Xenorhabdus nematophila Eric M ARTENS and Heidi G OODRICH -B LAIR University of Wisconsin-Madison, 1550 Linden Drive, Madison, WI 53706, USA The bacterium Xenorhabdus nematophila is a mutual- ist of the entomopathogenic nematode, Steinernema car- pocapsae . Most of the life cycle of these two organisms takes place inside larval-stage insects where the nema- tode and bacterium reproduce individually. However, a non-feeding form of the nematode, the infective juvenile (IJ), resides in the soil and is the vector for the nematode germline and for bacteria between insect hosts. Xenorhab- dus nematophila colonises a specialised intestinal organ of the IJ and can survive in this location for longer than 5 months despite a lack of nutritional uptake by the ne- matode/bacteria complex. Factors mediating colonisation of the nematode and the metabolic state of the bacterium during existence inside nematodes have not been char- acterised. We have developed a strategy to identify and characterise bacterial genes that are speci cally expressed during colonisation and growth inside nematodes. The re- sults of this analysis will yield insight into those bacter- ial functions that are important for establishing and main- taining a mutualistic interaction with the nematode. We are currently examining several nematode-inducible bac- terial loci to identify the speci c genes that are subjected to nematode-speci c expression. Future analysis will in- clude targeted mutation of nematode-inducible genes and determination of the resulting mutant phenotypes with re- gard to nematode-colonisation. 207 The bioassay of entomopathogenic nematodes on agricultural insect pests in laboratory conditions Miklós N ÁDASY 1 ; ¤ , Szilvia P EKÁR 1 , Attila L UCSKAI 1 , András F ODOR 2 , Gyula S ÁRINGER 1 and Csaba B UDAI 3 1 University of Veszprém, Georgikon Faculty of Agriculture, Deák F. u. 57, 8360 Keszthely, Hungary 2 Eotvos University, Department of Genetics, Pázmány Péter sétány 1/C 1117 Budapest, Hungary 3 Csongrad Country Plant Health and Soil Conservation Station, Biological Control and Quarantine Development Laboratory, P.O. Boksz 99, 6800 Hódmezõv_s_rhely, Hungary ¤ nadasy@georgikon. hu Entomopathogenic nematode/bacterium (EPN/EPB) sym- biotic complexes have been providing a rather ef cient and environmentally friendly way of controlling agricul- tural insect pests. Since the bacterial partner plays the important role of pathogenicity, we have developed sev- eral new EPN/EPB combinations between Heterorhabdi- tis spp. and Photorhabdus spp. strains at the Genetic De- partment of the Eötvös Loránd University, and tested them on several agricultural insect pests at the Plant Protection Institute of the VE Georgikon Faculty of Agriculture. The results of the previous gnotobiological analyses have been published elsewhere. In 1998 we tested some EPN/EPB symbiotic complexes that were applied in three doses (1/1, 1/10, 1/100 infective juveniles (IJ)/caterpillar) on last in- star wax moth larvae of Galleria mellonella as well as in two doses (3000 and 5000 IJ/white insect) on second stage white grubs of maybeetle ( Melolontha melolontha ) in laboratory conditions. It was concluded that the effec- tiveness of the new symbiotic complexes could be com- pared to that of natural EPN strains. In 1999 we tested the effectiveness of various Steinernema species ( S. anom- ali , S. serratum , S. riobrave , S. glaserii , S. carpocapsae Mex., T1, T2, T4, S. feltiae Nyíregyháza., IS6, (Israel), on German cockroaches ( Blattella germanica ) and on Peri- planeta americana . Two tests were applied: i ) lter pa- per method: 5000 IJ/5 cockroach/plate; ii ) feeding experi- ment: wax moth killed by nematodes were given to cock- roaches. Wax moth larvae killed by H. bacteriophora Bre- con and wax moth larvae killed by freezing were used as controls. In conclusion, S. carpocapsae gave positive results against cockroaches and the cockroaches ate the wax moth larvae killed by Steinernema but avoided those killed by Heterorhabditis . 208 Identi cation of Steinernema spp. and Heterorhabditis spp. using scanning electron microscopy of the labial region, lateral elds, vulval area, spicules and gubernacula Vol. 4(2), 2002 195</p>
<p>Entomopathogenic nematodes (187-221) Khuong B. N GUYEN ¤ and Byron J. A DAMS Entomology and Nematology Department, University of Florida, Gainesville, FL 32611-0620, USA ¤ kbn@u.edu Scanning electron microscopy techniques were used to identify morphological characters that are readily observed under light microscopy for the identi cation of species of Steinernema . Head shape and structures in the labial region of infective juveniles (IJ) can be used to divide steinernematids into four groups: i ) head without labial papillae, ii ) with six labial papillae, iii ) with two labial horns, and iv ) with swollen head. Formulae based on numbers of ridges in the lateral eld from anterior end to tail tip are also informative. Scanning electron microscopy of Heterorhabditis reveals that the H. megidis IJ has a membranous tube associated with its dorsal tooth. The spicules, gubernacula and vulval areas provide diagnostic characters among species of both genera. 209 Non-target mortality by and host searching behaviour of Heterorhabiditis bacteriophora in the presence of an aphid predator, Aphidoletes aphidimyza Jeff R. P OWELL ¤ and John M. W EBSTER Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6 ¤ jrpowell@sfu.ca Aphidoletes aphidimyza occurs naturally in several North American, European, and Asian eld crops and is released in glasshouses for aphid biocontrol. Experiments were conducted to determine how it might interact with an entomopathogenic nematode, Heterorhabditis bacteriophora . Fewer A. aphidimyza adults emerged from soil in 60 mm diameter Petri dishes inoculated with 1000 and 10 000 H. bacteriophora infective juveniles (IJ) than from uninoculated soil. No difference in percent adult emergence of A. aphidimyza was observed when IJ were applied 1, 6 or 9 days prior to emergence. Aphidoletes aphidimyza did not interfere with H. bacteriophora host searching behaviour: e.g. , no difference was observed in the number of IJ infecting Galleria mellonella larvae at the bottom of 276 ml styrofoam cups in the presence or absence of 100 A. aphidimyza near the soil surface. Heterorhabditis bacteriophora was not preferentially attracted to A. aphidimyza in a soil- lled 150 mm diameter Petri dish with one side containing one or 30 A. aphidimyza and the other containing none. This study suggests that H. bacteriophora applications may reduce A. aphidimyza populations, but that the presence of A. aphidimyza does not interfere with H. bacteriophora host searching behaviour. 210 The rst report of genetic diversity among Indian populations of entomopathogenic nematodes, Steinernema spp. and Heterorhabditis spp. Uma R AO ¤ , K.K. K AUSHAL , R. R ENUKA , K. U SHA and A.K. G ANGULY Division of Nematology, Indian Agricultural Research Institute, New Delhi 110012, India ¤ Umarao1@yahoo.com Insect pests are one of the major constraints of agricultural productivity in India. To utilise entomopathogenic nematodes for the management of regional insects, Steinernema spp. and Heterorhabditis spp. from different agro-climatic regions of India are being isolated, cultured and conserved in our laboratory. Nineteen EPN populations were assayed for their insect host range and analysed for genetic diversity using RAPD and PCR- RFLP of ribosomal DNA. Steinernema carpocapsae, S. glaseri and S. thermophilum – a new species recently reported from India – were included for comparison of Steinernema populations. Both and PCR-RFLP of rDNA could not detect any polymorphism among populations of Heterorhabditis spp. Both the pro ling systems revealed a high degree of polymorphism among Steinernema populations. RAPD UPGMA analysis clustered the populations into two main clusters. PCR-RFLP of rDNA of 13 Steinernema populations revealed similarity of only one population to S. glaseri. The internal transcriber spacers 1 and 2 of rDNA has been sequenced and aligned. Differences in the sequence alignment and the correlation between the observed genetic diversity revealed by RAPD and PCR – RFLP analysis will be discussed. 211 Entomopathogenic nematode occurrence in an Irish dune system Alec R OLSTON 1 , Martin D OWNES 2 and Christine G RIFFIN 2 1 Population Ecology Laboratory 2 Institute of Bioengineering and Agroecology, National University of Maynooth, Maynooth, Co. Kildare, Ireland Entomopathogenic nematodes are obligate parasites of in- sects. The two genera Steinernema and Heterorhabditis are ubiquitous soil organisms with world-wide distribu- 196 Nematology</p>
<p>Poster sessions tions. Insect-killing nematodes are traded globally as bi- ological control agents. Infective juveniles (IJ) emerge from the insect cadaver to search out a new host. The IJ invade the host via the mouth, anus or spiracles and re- lease a symbiotic bacteria which kills the insect by septi- caemia. Development into either males or females ( Stei- nernema spp.), or a hermaphrodite ( Heterorhabditis spp.) eventually leads to the production of further infective ju- veniles. These then emerge from the cadaver into the soil after 10-25 days depending on the species. Intensive sam- pling of the dune system on the geologically new Bull Is- land (Dublin Bay, Republic of Ireland) revealed the co- occurrence of the two genera. The genera were intimately associated, but Heterorhabditis occurred at lower frequen- cies. Prevalence was low with only 4.4% of samples re- vealing nematode presence ( Steinernema D 2.5%; Hete- rorhabditis D 1.9%). Populationswere patchy and the dis- tribution of each genus seems to be related to stable and unstable habitats. 212 Entomopathogenic nematodes in Norwegian forest soils Solveig Haukeland S ALINAS The Norwegian Crop Research Institute, Plant Protection Centre, Hogskoleveien 7, 1430 Aas, Norway solveig.haukeland@planteforsk.no A project on the use of entomopathogenic nematodes (EPN) for control of the pine weevil ( Hylobius abietis ) has been initiated. In the rst phase we are investigating the natural occurrence of EPN in forest soils. Soil samples were collected from several clear cut forest sites in autumn 2001. Samples were taken around the roots of tree stumps at each site. EPN were isolated using the Galleria technique.Preliminary results indicate that several species in the genus Steinernema are present. So far Steinernema krauseii has been identi ed which is a new record for Norway. Identi cation of the nematodes isolated is being conducted using morphometric and molecular techniques. 213 Survey of entomopathogenic nematodes endemic to pecan orchards of the southeastern US and their virulence to the pecan weevil (Coleoptera: Curculionidae) David I. S HAPIRO -I LAN 1 ; ¤ , Wayne A. G ARDNER 2 , James R. F UXA 3 , Bruce W. W OOD 1 , Khuong B. N GUYEN 4 , Byron J. A DAMS 4 , Richard A. H UMBER 5 and Michael J. H ALL 6 1 USDA-ARS, SEFTRNL, 21 Dunbar Rd, Byron, GA 31008, USA 2 Department of Entomology, University of Georgia, Grif n, GA 30223, USA 3 Department of Entomology, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA 4 Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611, USA 5 USDA-ARS, US Plant and Nutrition Lab, Ithaca, NY 14853, USA 6 LSU Agricultural Center, Shreveport, LA 71135, USA ¤ dshapiro@saa.ars.usda.gov The pecan weevil, Curculio caryae (Horn), is a major pest of pecans in the southeastern US. Entomopathogenic nematodes and fungi are potential alternatives to chemi- cal insecticides for C. caryae control. Our objective was to survey pecan orchards in the southeastern US for en- tomopathogenic nematodes and fungi determine the vir- ulence of the new isolates to C. caryae . Soil was col- lected from 105 sites in 21 orchards in Arkansas, Georgia, Louisiana, and Mississippi. Entomopathogens were iso- lated by exposing soil to C. caryae and greater waxmoth larvae, Galleria mellonella L. We isolated entomopatho- genic nematodes from six of the 21 orchards surveyed, respectively. Nematodes included Heterorhabditis bacte- riophora Poinar, Steinernema carpocapsae (Weiser), S. glaseri (Steiner), and S. rarum (Doucet). This is the rst report of S. rarum in the US. In laboratory assays, vir- ulence of 15 nematode isolates to C. caryae larvae was tested in small plastic cups containing soil. Results in- dicated poor susceptibility of the C. caryae larvae to entomopathogenic nematodes. However, high levels of nematode virulence were observed toward adult wee- vils, and several entomopathogenic fungal isolates caused signi cantly higher mortality in C. caryae larvae than other strains (including a commercial strain of Beauveria bassiana ). 214 Integration of Azadirachta indica with entomopathogenic nematodes for control of root grubs ( Holotrica serrata ) S. S IVARAMAKRISHNAN , K. M URUGAN and N. P OONKODI Division of Entomology, Department of Zoology, Bharathiar University, Coimbatore-641 046, Tamil Nadu, India Vol. 4(2), 2002 197</p>
<p>Entomopathogenic nematodes (187-221) Studies were conducted to explore the integration between neem seed kernel extract (NSKE), neem oil (NO) and Steinernema carpocapsae (SC) on root grub Holotrica serrata . Field collected third instar grubs were kept individually in microcosms lled with soil. Soil was exposed to various concentrations of NSKE, NO and Steinernema carpocapsae . Infective juveniles were added 0 to 16 days after application of NSKE and NO root grub mortality was noted every day. After combining and immediately applying the Steinernema carpocapsae, higher mortality was obtained against root grub. The survivability and virulence of SC in neem were maintained for 20 days with or without aeration. SC survived well in the neem concentrations and also the virulence was not affected by the neem concentrations with aeration and without aeration. Neem enhances the activity of nematodes. Entomophagous nematodes and neem can represent an eco-friendly strategy to control root grub in agriculture and forest ecosystems. 215 Ecological consequences of inundative biological control: impact of entomopathogenic nematodes on the nematode community in turfgrass Nethi S OMASEKHAR , Parwinder S. G REWAL , Elizabeth A.B. D ENARDO and Benjamin R. S TINNER Department of Entomology, Ohio State University, OARDC, Wooster, OH 44691, USA Biological control is often touted as an ecologically safe pest management approach. This notion is based on its relative safety to humans and above ground ora and fauna. However, there is a paucity of data to support that large-scale releases of biocontrol agents do not have an impact on below ground food webs. We addressed this issue using entomopathogenic nematodes and native nematode community in a turfgrass ecosystem as a model. Application of Heterorhabditis bacteriophora strain GPS11, H. bacteriophora strain HP88, and H. indica signi cantly reduced the abundance, species richness, diversity, and maturity of the nematode community by reducing the number of genera and abundance of plant- parasitic but not free-living nematodes. In contrast to the entomopathogenic nematode treatments, trichlorfon, a commonly used insecticide in turfgrass, reduced the number of genera, abundance and diversity of nematode community by adversely affecting both plant-parasitic and free-living nematodes. The reduction in abundance and diversity of plant-parasitic nematodes without any adverse effect on free-living nematodes that play a role in nutrient cycling may be a bene cial non-target effect of entomopathogenic nematodes. 216 Detection of entomopathogenic nematodes and their possible use under IPM in Pakistan Manzoor H. S OOMRO 1 , F. S HAHINA , M.A. M AQBOOL 2 and Iftikhar A HMAD 1 1 National IPM Programme, National Agricultural Research Centre, Islamabad, Pakistan 2 National Nematological Research Centre, University of Karachi, Karachi, Pakistan In Pakistan the studies on biology, taxonomy and ef cacy of entomopathogenic nematodes (EPNs) were initiated in 1996. Since then during extensive surveys, over 1000 soil samples were collected from diverse habitats of Pakistan with emphasis on Sindh Province. Nematodes were collected using Galleria mollonella soil trap method. Three isolates of Steinernema and 59 of Heterorhabditis were detected; of which, 22 isolates were identi ed as H. indica. Out of the identi ed EPNs, two are new species; one has been described as Steinernema pakistanense Shahina et al. 2001, while the other, Steinernema species is in the process of description. Pathogenicity of new indigenous EPN, S. pakistanensis was tested against seven insect pests of common occurrence and agricultural importance under laboratory conditions and con rmed on Helicoverpa armigera, Earias insulana, E. vittella, Papillio demoleus, Leucinodes orbonalis, Etiella zinkenella, Hollotrichia consanguinea . Mortality was higher (up to 100%) on early stages of insect larvae ( H. armigera ) as compared to fourth and fth stage larvae. Search for more indigenous EPNs is continuing and under the National IPM Programme, eld-testing of promising species will be undertaken during the year 2002. The farmers would be trained for conservation of natural enemies including EPNs through the farmer eld school (FFS) approach particularly in cotton crop, which receives the largest amount (60%) of pesticides in Pakistan. 217 Heritability of the liquid culture potential of the entomopathogenic nematodes Heterorhabditis bacteriophora O. S TRAUCH , S.-A. J OHNIGK , S. H OLLMER and R.-U. E HLERS ¤ 198 Nematology</p>
<p>Poster sessions Institute for Phytopathology, University of Kiel, Department of Biotechnology & Biological Control, Klausdorfer Str. 28-36, 24223 Raisdorf, Germany ¤ ehlers@biotec.uni-kiel.de The infective stage of Heterorhabditis bacteriophora is the mobile, but developmentally arrested dauer juvenile (DJ). For commercial application, nematodes are produced in liquid culture. Prior to the inoculation of the DJ, their symbiotic bacterium Photorhabdus luminescens is cultured. The DJ exit from the arrested stage (recovery) and develop to reproductiveadults. Recovery is a response to bacterial food signals. In liquid culture the percentage of DJ recovering from the DJ stage is highly variable, which signi cantly in uences the number of reproducing hermaphrodites and the nal DJ yields. The heritability of the disposition to recover from the DJ stage and of the nal DJ yield in liquid culture has been evaluated. From a hybrid strain 30 homozygous inbred lines were established by inbreeding over seven generations. These inbred lines were propagated in liquid culture several times; the percentage of recovered DJ and the nal DJ yields were recorded. The calculated heritability for the DJ recovery was low ( h 2 D 0 : 38). No signi cant genetic variability could be detected for this trait. In contrast, a high heritability ( h 2 D 0 : 90) was found for the total number of DJ produced in the liquid medium. 218 Potential new targets for entomopathogenic nematodes in biological control of urban tree pests Marek T OMALAK Department of Biological Pest Control and Quarantine, Institute of Plant Protection, ul, Miczurina 20, 60-318 Poznan, Poland M.Tomalak@ior.poznan.pl Many leaf feeding pests of urban trees pupate and/or overwinter in the soil, the most suitable environment for entomopathogenic nematodes. During this period the insects can be challenged with Heterorhabditis- or Steinernema- based bioinsecticides. Susceptibility of the most important urban tree leaf beetles and saw ies to S. feltiae and H. megidis was examined in laboratory and eld conditions. Last instar larvae and pupae of all tested leaf beetles ( Altica quercetorum , Agelastica alni , Phytodecta quinquepunctata and Phyllodecta laticolis ) and some saw ies ( Acantholyda erythrocephala, Arge berberidis, A. pagana ) proved to be highly susceptible to nematode infection. A tight pupal cocoon of the remaining saw y species ( Pristiphora abietina, Caliroa annulipes ), however, made nematode penetration dif cult or impossible. For the susceptible hosts nematodes signi cantly reduced the number of adult insects emerging from the soil after pupation. They could also develop and recycle in the insect cadaver. Signi cant differences were found between the ef cacy of H. megidis and S. feltiae strains and isolates tested against different insect species. The results suggest that entomopathogenic nematodes should be considered as potential effective control agents which could be safely used against many tree leaf beetles and saw ies damaging urban parks and forests. 219 Potential of entomopathogenic nematodes for the control of cabbage root y Deena M. W ILLMOTT ¤ and Andrew J. H ART Department of Entomological Sciences, Horticulture Research International, Wellesbourne, Warwick, CV35 9EF, UK ¤ Deena.Willmott@hri.ac.uk The cabbage root y ( Delia radicum ) is the major pest of brassica vegetable crops in the northern temperate region; larvae cause extensive damage by feeding on plant roots. Chemical insecticides have traditionally been used to control this pest. However, with the imminent withdrawal of organophosphorus insecticides, alternative management strategies need to be developed which may include the use of entomopathogenic nematodes as biopesticides. Under glasshouse conditions, the susceptibility of cabbage root y larvae to ten isolates of entomopathogenic nematodes was examined, using cauli ower ( Brassica oleracea var. botrytis ) as the host plant. Steinernema af ne (isolate 179) gave the highest level of control, killing approximately 66% of larvae within 28 days. The least signi cant control was given by Steinernema E1 and F1 (194 and GWE63) and two Heterorhabditis isolates (K122 and UK211) which killed approximately 30% of larvae in 28 days. A second experiment compared the performance of S. af ne and Nemasys ® (Microbio Ltd), a commercial formulation of S. feltiae , over a range of doses (from 8000 to 64 000 nematodes per pot). Steinernema af ne controlled signi cantly more of cabbage root y (54%) than Nemasys ® (36%) and may have potential for commercial development. Vol. 4(2), 2002 199</p>
<p>Entomopathogenic nematodes (187-221) 220 On the entomopathogenic nematodes belonging to genera Steinernema and Heterorhabditis from the Russian Far East and comparison with entomopathogenic nematode fauna in Japan Mutsuhiro Y OSHIDA National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai Tsukuba, Ibaraki 305-8604, Japan mutsuysd@niaes.affrc.go.jp Entomopathogenic nematodes were collected in southern Primorye and southern Sakhalin, grant-aided by Gene Bank Project of Ministry of Agriculture, Forestry and Fisheries and supported by the Institute of Marine Biology and the Institute of Parasitology of the Russian Academy of Sciences. A total of 197 soil samples from 34 sites were tested for the presence of the nematodes using the Galleria baiting technique. Forty-two nematode isolates were detected from 14 sites. The nematodes were divided into six RFLP types. Three of them were identi ed as S. kraussei , S. feltiae and Heterorhabditis megidis and another three were tentatively designated as S . spp. primorye1, sakhalin1, sakhalin2 . Steinernema kraussei was the dominantspecies (nine/14 sites) in this survey and was isolated from coasts to mountains. However, it has been detected only from two coastal sites in Hokkaido, the closely related region with the Russian Far East. Steinernema feltiae was detected only from a coastal grassland in Sakhalin and also mainly from coastal sites in Hokkaido. Heterorhabditis megidis was isolated from both Vladivostok and Sakhalin, but has not been isolated from Hokkaido. Steinernema sp. sakhalin2 corresponded to S . sp. MY7 from Japan and S . sp. primorye1 was recently recognised among the isolates detected from Hokkaido. 221 Growth and reproduction of Heterorhabditis bacteriophora on Xenorhabdus poinarii RS92 Toyoshi Y OSHIGA ¤ and Ralf-Udo E HLERS Institute for Phytopathology, Christian-Albrechts-University Kiel, Klausdorfer Str. 28-36, 24223 Raisdorf, Germany ¤ tyoshiga@cc.saga-u.ac.jp Heterorhabditis bacteriophora is an entomopathogenic nematode which has a speci c symbiotic relation to the bacterium Photorabdus luminescens . To understand the symbiotic effect of Photorhabdus and Xenorhabdus on H. bacteriophora , the bacteria were examined for their potential to support nematode growth. Axenic 1st stage larvae of H. bacteriophora obtained by surface sterilisation of eggs that were inoculated on lipid agar plates along with 24 h bacterial cultures. Heterorhabditis bacteriophora grew and reproduced well not only on Photorhabdus bacteria isolated from H. bacteriophora and H. megidis but also on X. poinarii RS92 from Steinernema glaseri . Nematode growth was not supported by the symbiont of H. indica and by other Xenorhabdus spp. tested. The hermaphroditesof H. bacteriphora grown on X. poinarii RS92 were signi cantly smaller than those grown on their own symbiont. Dauer juveniles obtained from the X. poinarii RS92 culture did not retain the bacteria in their intestine nor recovered from the dauer stage in a fresh X. ponarii RS92 culture. Also, H. megidis and H. indica as well as S. carpocapsae grew and reproduced on X. poinarii RS92. These results indicate that X. poinarii RS92 is a Xenorhabdus bacterium that supports the growth of both heterorhabditid and steinernematid nematodes. 200 Nematology</p>
<p>Poster sessions 222 Different developmental responses of virulent and avirulent isolates of Bursaphelenchus xylophilus to Monochamus alternatus Takuya A IKAWA 1 ; ¤ , Katsumi T OGASHI 2 and Hajime K OSAKA 1 1 Forestry and Forest Products Research Institute, Tsukuba, Ibaraki 305-8687, Japan 2 Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8521, Japan ¤ taikawa@ffpri.affrc.go.jp It is known that there is a great variation in virulence of Bursaphelenchus xylophilus, which is the causative agent of pine wilt disease and is transmitted from wilt-killed to healthy pine trees by the insect vector, Monochamus alternatus . To compare the developmental responses to M. alternatus between the two nematode isolates of different virulence, the production of dispersal forms and the number of nematodes carried by newly-emerged M. alternatus adult (initial nematode load) were investigated using pine bolts. The numbers of total nematodes, dispersal juveniles (third-stage dispersal juvenile and fourth-stage dispersal juvenile) and fourth-stage dispersal juveniles were much smaller in the avirulent isolate than in the virulent one around pupal chambers. The proportions of dispersal juveniles produced in a population and the proportion of third-stage dispersal juveniles developing to fourth-stage dispersal juveniles were also smaller in the avirulent isolate. Although the proportion of fourth-stage dispersal juveniles boarding beetles was equal between the two isolates, the number of them was much smaller in the avirulent isolate. A small initial nematode load of the avirulent isolate was ascribed to a smaller rate of reproduction and lower productive rates of third- and fourth-stage dispersal juveniles for the avirulent isolate. 223 Effects of phytohormones and root diffusates on the surfaces of plant-parasitic nematodes Abdellah A KHKHA 1 ; ¤ , John K USEL 1 , Malcolm K ENNEDY 2 and Rosane C URTIS 3 1 Davidson Building, Division of Biochemistry & Molecular Biology, University of Glasgow, Glasgow G12 8QQ, UK 2 Graham Kerr Building, Division of Environmental and Evolutionary Biology, University of Glasgow, Glasgow, G12 8QQ, UK 3 Nematode Interactions Unit, IACR-Rothamsted, Harpenden, Herts AL5 2JQ, UK ¤ a.akhkha@bio.gla.ac.uk The direct effects of root diffusates and phytohormones (auxin and kinetin) on the surface lipophilicity of the plant-parasitic nematodes Globodera rostochiensis and Meloidogyne incognita were investigated.The uorescent lipid probe AF18 (5-N-(octodecanoyl) amino uorescein) was used to detect surface changes. Root diffusates increased AF18 uptake by G. rostochiensis while it had no effect on M. incognita . Kinetin and auxin decreased AF18 uptake in G. rostochiensis , while they had an opposite effect on M. incognita . Auxin/kinetin ratio was also found to be important in triggering the surface changes, especially at high concentrations. Whether plant nematodes have auxin and/or kinetin binding proteins is discussed as well as the mechanism behind the surface lipophilicity changes. The implication of these changes in the establishment of infection is also discussed. 224 Effect of population densities of Heterodera glycines race 3 on leaf area, photosynthesis and yield of soybean Guilherme Lafourcade A SMUS 1 ; ¤ and Luiz Carlos C.B. F ERRAZ 2 1 EMBRAPA-CPAO, P.O. Box 661, 79804-970, Dourados, MS, Brazil 2 ESALQ/USP – Zoology Department, P.O. Box 9, 13418-900, Piracicaba, SP, Brazil ¤ asmus@cpao.embrapa.br The effect of Heterodera glycines race 3 on photosynthe- sis, leaf area, and yield of susceptible soybean ‘Embrapa 133’ was studied in two experiments carried out under glasshouse conditions. Soybean seeds were sown in 1.5 l (Experiment 1) or 5.0 l (Experiment 2) clay pots lled with a sterilised mixture of eld soil C sand (1:1). Eight days after sowing, seedlings were thinned to one per pot, and 1 day later inoculated with 0, 1200, 3600, 10 800, 32 400, or 97 200 second stage juveniles ( D Pi ). Exper- iment 1 was continued until 45 days after inoculation whereas experiment 2 extended until harvest time. Data on plant physiological processes were taken at 10-day in- tervals during the experiments. Data on fresh root weight, top dry weight, grain yield, and nematode reproduction factor were obtained at the end of the trials. For both ex- periments, a statistical design of randomised blocks with six treatments ( Pi values) was established and each exper- imental unit (one plant growing per pot) was replicated ten times. There was a marked reduction in both photo- Vol. 4(2), 2002 201</p>
<p>Physiology (222-243) synthetic rate and chlorophyll content, as well as evident yellowing of the leaves of the infected plants. Even at the lowest Pi , the effect of H. glycines on top dry weight or grain yield were quite severe. Also, soybean yield was highly correlated with the integrated leaf area. 225 Leaf area, photosynthesis and yield of soybean as affected by initial population densities of Meloidogyne javanica Guilherme Lafourcade A SMUS 1 ; ¤ and Luiz Carlos C.B. F ERRAZ 2 1 EMBRAPA-CPAO, P.O. Box 661, 79804-970, Dourados, MS, Brazil 2 ESALQ/USP – Zoology Department, P.O. Box 9, 13418-900, Piracicaba, SP, Brazil ¤ asmus@cpao.embrapa.br The effect of Meloidogyne javanica parasitism on the leaf area, photosynthesis, and yield of two Brazilian soybean varieties, Embrapa 133 (susceptible) and Coodetec 201 (tolerant), were studied under glasshouse conditions. Two similar experiments were set up, one continued until 48 days after plant inoculation, and the other until plant harvest. The plantlets were individually inoculated with 0, 1200, 3600, 10 800, 32 400 or 97 200 second stage juveniles ( D Pi ). Data on physiological processes of the plants were taken at 10-day intervals throughout the experiments, whereas data on fresh root weight, top dry weight, grain yield and nematode reproduction factor were obtained at the completion of the trials. A statistical design of randomised blocks with treatments arranged according to a 2 £ 6 factorial model (varieties £ Pi ) was established and each experimental unit (one plant growing per pot) was replicated ten times. Values of photosynthesis rate, stomatic conductance, chlorophyll uorescence, leaf colour and chlorophyll content were slightly affected by M. javanica for both tested varieties. Conversely, soybean leaf area, fresh root weight, top dry weight, and grain yield were markedly reduced by the nematode at the highest Pi values. Also, soybean yield was highly correlated with the integrated leaf area. 226 Characterisation of a member of the LEA gene family from the anhydrobiotic nematode Aphelenchus avenae John A. B ROWNE 1 ; ¤ , Katharine M. D OLAN 1 , Alan T UNNACL IFFE 2 and Ann M. B URNELL 1 1 Institute of Bioengineering and Agroecology, National University of Ireland Maynooth, Maynooth Co. Kildare, Ireland 2 Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QT, UK ¤ John.A.Browne@may.ie When subjected to desiccation some nematodes can enter a state of suspended animation known as anhydrobiosis. Anhydrobiotic nematodes synthesise high concentrations of the non-reducing sugar trehalose during the induction of anhydrobiosis. Trehalose is believed to protect mem- branes and proteins from desiccation damage by replac- ing structural water, and to contribute to the formation of an intracellular organic glass, which is thought to stabilise the cell contents. In anhydrobiotic plants, sucrose plays a similar role. However, several lines of evidence indicate that non-reducing sugars alone are not suf cient to con- fer anhydrobiosis, and that additional adaptations are re- quired. To identify these additional adaptations, we have investigated gene expression in Aphelenchus avenae un- dergoing anhydrobiosis. A number of genes were found to be upregulated in nematodes exposed to 90% relative humidity for 24 h. Of particular interest was a strongly in- duced transcript whose sequence suggests that it encodes a member of the group 3 subclass of LEA (Late Embryo- genesis Abundant) proteins. LEA proteins accumulate in response to water de cit in many plants but are especially abundant in anhydrobiotic plants and in maturing seeds and pollen. We will present our data on the molecular phy- logeny of the A. avenae LEA3 gene and on its induction in A. avenae by various environmental stresses. 227 Dual modes of reproduction in Caenorhabditis elegans J. C HEN and E.P. C ASWELL -C HEN Department of Nematology, University of California, Davis, CA 95616, USA Caenorhabditis elegans is a model system for studying development and reproduction. The relative investment of energy in growth, maintenance, or reproduction is a classic question in the evolutionof reproductivestrategies. Here we report that when C. elegans is starved, it alters its mode of reproduction from ovipary to vivipary wherein larvae develop within the parent body before live birth. Facultative vivipary was observed in worms placed in water, on culture plates and in soil microcosms, was induced by starving late L4s, young adults, and gravid adults, and was reversible by restoring food. Without 202 Nematology</p>
<p>Poster sessions food, vivipary resulted in the death of parent worms because their progeny appeared to consume the parent body contents. The larvae that resulted from vivipary developed to reach a normal lifespan and had normal egg production, as compared to larvae arising from ovipary. Larvae produced by vivipary were able to enter the dauer stage under crowding and limited food but, in contrast to larvae arising from ovipary, some larvae produced by vivipary were able to enter the dauer stage under complete starvation. We infer that the combination of vivipary, androdioecy, and the dauer stage represent life-history adaptations that ensure survival of dispersal propagules under extreme food limitation. 228 Inhibition of sterol metabolism in Caenorhabditis elegans by AY-9944 David J. C HITWOOD Nematology Laboratory, ARS, U.S. Department of Agriculture, Bldg. 011A, room 165B, BARC-West, Beltsville, MD 20705, USA chitwood@ba.ars.usda.gov Caenorhabditis elegans and some other nematodes are capable of attaching a methyl group to the nucleus of sterols at the C-4 position. In C. elegans , 4-methylcholest-8(14)-enol is the most abundant 4- methylsterol produced, and smaller quantities of 4- methylcholest-7-enol also occur. The purpose of this study was to treat C. elegans with a known inhibitor of steroid C-7 double bond isomerisation in order to more fully understand the pathway of 4-methylsterol formation. Thus, C. elegans was propagated in sterile semi-de ned medium with or without 50 mg/l AY- 9944. The media were supplemented with sitosterol as a dietary sterol. Lipids were extracted from the nematodes and saponi ed; sterols were isolated with column chromatography and identi ed with gas chromatography. The sterols of inhibitor-untreated nematodes contained 91.4% 4-desmethylsterol plus 8.6% 4-methylsterol; the inhibitor-treated nematode sterol contained only 4.6% 4-methylsterol. The 4-methylcholest-8(14)-enol:lophenol ratio in control nematodes was 9.75 but only 0.71 in treated nematodes. The results are consistent with a pathway involving the methylation of cholest-7-enol to form lophenol as an intermediate in the production of the nal product of the methylation pathway, 4- methylcholest-8(14)-enol. 229 The kinase cascade possibly involved in the odorant signaling of Meloidogyne artiellia Maria Rosaria C ORTESE 1 ; ¤ , Mauro D I V ITO 2 , Elena F ANELLI 1 and Carla D E G IORGI 1 1 Università degli Studi di Bari, via Orabona n ± 4, 70126 Bari, Italy 2 Istituto di Protezione delle Piante CNR, via Amendola 165/A, 70126 Bari, Italy ¤ m.cortese@bilogia.uniba.it The plant parasitic nematode Meloidogyne artiellia causes signi cant economic losses worldwide by at- tacking the roots of several cultivated crops. Although very little is known about the host-parasite interactions, chemosensation processes might play a key role in the recognition of the plant host thus involving specialised signal transduction pathways. We are investigating some aspects of the mechanism of signal transduction using molecular and biochemical approaches in order to elu- cidate roles of speci c proteins in the signal cascade. In particular, we are interested in RAS-Mapk pathway that was demonstrated to be involved in olfaction in C. ele- gans . We have isolated and characterised in M. artiellia the corresponding genes of let60 , lin45 , mek2 and mpk1 that constitute this pathway in C. elegans . The compari- son of the sequences of these four genes from C. elegans and M. artiellia and kinase assays with GST-recombinant proteins mek2 and mpk1 of the parasite con rm the role of the isolated genes in the RAS-Mapk pathways. The ap- proach of a phosphorylation screening of a cDNA library of M. artiellia will allow the isolation of all the possi- ble substrate proteins of the last member of this cascade mpk1. 230 Suitability of a mathematical model to describe the effect of temperatures and exposure times on the survival of the sugar-beet nematode Heterodera schachtii Trifone D ’A DDABBO ¤ , Nicola S ASANELLI , Nicola G RECO , Vincenzo S TEA and Antonio B RANDONISIO Istituto per la Protezione delle Piante, Sezione di Bari, C.N.R., Via G. Amendola 165/A, 70126 Bari, Italy ¤ nematd12@area.ba.cnr.it The effect of combinations of temperatures and exposure times on the survival of Heterodera schachtii was assessed in experiments under laboratory conditions. In the rst experiment cysts in water were exposed at 25, 35, 37.5, Vol. 4(2), 2002 203</p>
<p>Physiology (222-243) 40, 42.5, 45, 47.5, 50 or 52.5 ± C for a maximum of 2 h. In the second experiment cysts in naturally infested soil were exposed at 32.5, 35, 37.5, 40, 42.5, or 45 ± C for a minimum of 2 to a maximum of 2048 h. Viability of eggs in cysts was assessed by hatching tests in a 3 mM zinc chloride solution. Viability in water was suppressed after 2 h exposure at 50 ± C and inhibited after 1-2 h at 52.5 ± C. Emergence of juveniles from cysts in soil increased after treatments at rather low temperature x exposure time combinations and was suppressed at high combinations. Egg mortality started after exposures of 256 h at 40 ± C, 32 h at 42.5 and 16 h at 45 ± C. Eighty one, 31 and 7 h of exposure were necessary to kill 50% of the nematode egg population at 40, 42.5 and 45 ± C, respectively. Data tted the models P t D P 0 10 ¡ t=.q C mT / and P T 1 D P T 0 10 ¡ 1T =.z ¡ pt/ for m D ¡ 0 : 0111, q D 0 : 8238, z D 2 : 444 and p D ¡ 0 : 236. 231 Interaction of root-knot nematode infection and drought stress in cotton R.F. D AVIS 1 ; ¤ and H.J. E ARL 2 1 USDA-ARS, P.O. Box 748, Tifton, GA 31793, USA 2 University of Georgia, Dept of Crop and Soil Sciences, 4107 Miller Plant Sciences, Athens, GA 30602, USA ¤ rfdavis@tifton.cpes.peachnet.edu Drip irrigation was used in a eld with a loamy sand naturally infested with Meloidogyne incognita to create low, medium and high levels of drought stress, though rainfall minimised drought stress early in the season. Fumigation with 1,3-dichloropropene (0 or 56 l/ha) was used to create a range of nematode densities. Three metres of each plot were hand harvested and ginned to provide lint and seed yield. A subsample of lint was analysed for bre quality, including bre length and micronaire. Covariance analysis was used to determine within each level of drought stress the relationship between nematode densities at mid-season and seed weight, lint weight, bre length, and micronaire at harvest. For all levels of drought stress, seed weight ( P D 0 : 03), lint weight ( P D 0 : 05), and bre length ( P D 0 : 07) decreased and micronaire ( P D 0 : 02) increased as nematode populations increased. For seed weight and micronaire, the relationships with nematode densities were similar (alpha D 0.10) among the three levels of drought stress (similar slopes and intercepts), but only slope was similar for length. The decrease in lint weight with increasing nematode densities was greater ( P D 0 : 07) at the high level of drought stress than at the lower levels of stress. 232 Detection of changes occurring during recovery from the dauer stage in Heterorhabditis bacteriophora Katharine M. D OLAN 1 ; ¤ , John T. J ONES 2 and Ann M. B URNELL 1 1 Institute of Bioengineering and Agroecology and Department of Biology, National University of Ireland Maynooth, Maynooth, Co Kildare, Ireland 2 MBN Unit, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK ¤ Katharine.M.Dolan@may.ie When conditions are unfavourable for reproduction in Heterorhabditis bacteriophora , a long lived, non-feeding, survival and dispersal stage, the dauer juvenile (DJ), is formed. This DJ stage is also adapted for host nding and infection. When it infects a suitable host, the DJ recovers and resumes growth and development. We describe a series of methods for improved detection of recovery in H. bacteriophora. We also describe some of the physiological changes that occur immediately after the onset of recovery in these nematodes as revealed using uorescent nucleic acid binding SYTO dyes. Although recovery could be monitored using morphological changes, we found that observation of the uptake of uorescent latex microspheres by recovering nematodes was a far more sensitive and ef cient means of detecting recovery. SYTO dyes were also found to be useful indicators of recovery, binding to the pharyngeal glands and genital primordia as little as 3 h after the onset of recovery. The use of SYTO dyes also indicates that the pharyngeal glands produce large quantities of RNA following the onset of recovery, implying that these structures may produce proteins important in the infection and/or feeding process of H. bacteriophora . 233 Isolation and characterisation of genes induced by desiccation stress in the insect-killing nematode Steinernema feltiae Tali Z. G AL ¤ , Hinanit K OLTAI and Itamar G LAZER Department of Nematology, ARO, The Volcani Center, Bet Dagan, 50250, Israel ¤ Vptali@agri.gov.il The insect-killing nematodes of the Steinernematidae infect and kill a wide range of insect species and are considered among the most promising alternatives to chemical control of insect pests. Steinernema feltiae can partially tolerate desiccation by entering a shallow 204 Nematology</p>
<p>Poster sessions dormancy and thus may serve as a model to study desiccation stress tolerance for steinernematid nematodes. Using cDNA subtractive hybridisation we identi ed IS6 genes that are differentially expressed during exposure to desiccation stress. One hundred and ten genes were identi ed, among them Late-Embryogenic-Abundant gene ( Sf-LEA ) and aldehyde dehydrogenase ( Sf - ALDH ), both known to be involved in response to water stress in other organisms. Furthermore, using real-time PCR, we detected a signi cant increment in the steady state level of the gene transcription products upon 8 h of nematode exposure to desiccation, and further increase upon 24 h of desiccation. Future studies of desiccation tolerance, including identi cation of additional desiccation-related genes and study of their biological roles and regulation, will shed light on the genetic and biochemical alterations evolved in desiccation tolerant organisms. 234 Are there hatching inhibitor factors of Globodera pallida in potato tubers? Avelino G ARCÍA -A LVAREZ 1 ; ¤ , María A RIAS 1 , Antonio B ELLO 1 , Javier Gutiérrez L UIS 2 and Alejandra L ÁZZARO 2 1 Dpto de Agroecología, CCMA, CSIC, Serrano 115 dpdo, 28006 Madrid, Spain 2 Instituto Universitario de Bio-Orgánica, Universidad de La Laguna, Avda Astrofísico Sánchez 2, 38206, La Laguna, Tenerife, Spain ¤ aga@ccma.csic.es Co-evolution of potato plant Solanum tuberosum and potato cyst nematode (PCN) Globodera pallida for millions of years has resulted in a closed interrelationship in which the nematode biological cycle depends on root diffusates that stimulate the hatching process of second stage juveniles (J2). Hatching factors (HF) are present not only in roots but also in leaves and other parts of the potato plant, except for tubers. However, the existence of chemicals which inhibit the HF is well-known, and these have been found in several non-host species for PCN, such as white mustard, asparagus or Blupeurum salicifolium . Recently hatching inhibitors (HI) have been identi ed in potato root leachates, though information does not exist about their presence in tubers. The potato industry produces thousandsof tons of potato tuber wastes every year and this material could be used as a potential source of HI. Bioassays with cysts of G. pallida have been carried out using different fractions of peel tuber extracts in n-hexane, dichloromethane and Eethyl acetate. After 18 days the cysts were subjected to the action of potato root leachates. In those cysts with an n-hexane fraction pre-treatment no hatching of J2 was observed. This could indicate the presence of HI in potato peel. 235 Effect of heavy metals (zinc and lead) on soil nematode fauna Ludmila G RUZDEVA ¤ , Elizaveta M ATVEEVA and Tatiana K OVALENKO Institute of Biology, Karelian Research Centre RAS, Pushkinskaya st, 11, Petrozavodsk, 185610, Karelia, Russia ¤ gruzdeva@krc.karelia.ru Changes of nematode fauna in soil polluted with zinc (ZnSO 4 – 2500 mg/kg) and lead (PbNO 3 – 500 mg/kg of soil) were investigated. Faunistic diversity, nematode population density, ecotrophic structure and maturity in- dex of nematode communities were analysed. Soil sam- ples were collected monthly in 2000 (April – Septem- ber) and twice in 2001 (May and September). Simulta- neously, an experiment on the growth of nematodes of genus Cephalobus on medium with addition of Zn and Pb in increasing concentrations under laboratory condi- tions was carried out. Both salts were toxic for nema- todes. They caused a decrease in population density and diversity. Trophic structure of the nematode communities was changed, immediately after heavy metal application. The number of representatives of Rhabditidae sharply in- creased (up to 78%, especially in the variant with Zn); later the number of polyphagous and predaceous nema- todes decreased. Under Zn application these groups dis- appeared totally from the nematode fauna. Maturity index of the nematode communities ( 6MI ) was lower in vari- ants with heavy metals (2.1-2.6) compared to the control (2.7-2.8). In the laboratory experiment, the toxic effect of Zn and Pb was expressed in a decrease in fecundity of nematodes and size of individuals in the population. Neg- ative effects were intensi ed with increased heavy metal concentration. 236 Presence of Meloidogyne sp. males in thickenings of the end of soybean lateral roots Eugenia L ORENZO 1 ; ¤ , Marcelo E. D OUCET 1 and Susana S UAREZ 2 1 Orientación Morfología Vegetal, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional Vol. 4(2), 2002 205</p>
<p>Physiology (222-243) de Río Cuarto, Agencia Postal N ± 3, 5800 Río Cuarto, Provincia de Córdoba, Argentina 2 Orientación Morfología Vegetal, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Agencia Postal N ± 3, 5800 Río Cuarto, Provincia de Córdoba, Argentina ¤ elorenzo@exa.unrc.edu.ar Soybean plants ( Glycine max L. Merr. A 5435 variety) from Berrotarán, province of Córdoba, Argentina, showed highly galled radical systems. Females of Meloidogyne sp. were extracted from inside prominent galls located on principal and lateral roots. Several lateral roots showed particularly thickened ends. Dissection of the lateral roots revealed the presence of several males inside them. The analysis of histologicalsections showed giant cells around them. Thickenings at the end of soybean lateral roots represent another element of analysis to detect nematodes of the genera Meloidogyne. 237 Effect of plant defence elicitors and cations on reproduction of RKN on tomato S. M OLINARI Istituto di Protezione delle Piante – CNR, Via G. Amendola 165/A, 70126 Bari, Italy nemasm04@area.ba.cnr.it A number of plant defence elicitors, such as salicylic acid (SA), acetylsalicylicacid (AcSA), jasmonic acid (JA) and isonicotinic acid (INA), has been used to test their effect on root-knot nematode reproduction on tomato. Furthermore, tomato response to RKN was assayed after incubation of roots in concentrated solutions of K C , Na C , Fe 3 C and the Ca 2 C chelator EDTA. In particular, roots of young seedlings of susceptible tomato were immersed overnight in appropriate solutions of SA, AcSA, JA, INA, KH 2 PO 4 , Na 2 HPO 4 , EDTA, FeCl 3 and water as a control, washed and immediately inoculated with over 100 Meloidogyneincognita active J2 per seedlings. Inoculated tomato plants were grown in a glasshouse at 25-27 ± C for 6 weeks. Reproduction index was determined as number of egg masses per root system and compared to untreated control. Previous treatment of tomato seedlings with INA, Na C and EDTA markedly reduced RKN reproduction on tomato. The effect of different concentrations of chemicals has been also evaluated. Generally, the effect on RKN reproduction of the single chemical does not exceed a 50% decrease compared with untreated controls. The maximum inhibitory effect is associated with a threshold concentration; higher concentrations, if not phytotoxic, are ineffective in controlling the parasites. 238 Olfaction and odour discrimination in the insect parasitic nematode Heterorhabditis bacteriophora Damien M. O’H ALLORAN ¤ and Ann M. B URNELL Institute of Bioengineering and Agroecology and Department of Biology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Ireland ¤ damien.m.ohalloran@may.ie The survival of any organism depends greatly on its ability to monitor the external environment. Organisms have developed a wide range of sensory systems to detect, transduce and evaluate relevant environmental signals. Olfaction is a primary neurosensory function and it remains one of the major senses by which organisms assess their environs. Heterorhabditis bacteriophora lives at a soil-water interface and so encounters many types of volatile and water-soluble molecules in its environment. We show that its complex chemical vocabulary enables H. bacteriophora to bind and identify many classes of odorant molecules. These include many host-related chemicals, including carbon dioxide, as well as more complex organic cues such as long chain alcohols. We show that H. bacteriophora detects numerous volatile and water-soluble chemicals, which can be either attractant or repellent depending on their concentration. Using behavioural assays, we have identi ed several classes of receptors and have investigated their af nity for host- related cues. 239 Video-assisted analysis of anhydrobiotic process in Aphelenchus avenae on sucrose-amended agar substrates Rhyosuke O HTSUBO , Nobuyoshi I SHIBASHI ¤ and Eizo K ONDO Saga University, Saga 849-8502, Japan ¤ ishibasn@cc.saga-u.ac.jp The fungivorous nematode, Aphelenchus avenae , comes into anhydrobiosis under slowly drying conditions, however, the process leading to the anhydrobiotic state has not yet been fully understood. The present study individually examined the process leading to coiling of the nematodes on agar plates with added sucrose and their survival after desiccation treatment. Fourth stage juveniles or young adults of A. avenae individually 206 Nematology</p>
<p>Poster sessions placed on 5% agar substrate containing 0.8 M sucrose showed the highest proportion of nematodes in the coiling posture. Video-assisted image analysis indicated that the nematodes became quiescent within 2-3 h after being placed on the agar plate, then gradually resumed mobility and became coiled. Coiled or uncoiled nematodes were individually transferred, without destroying their shape, to a desiccator ( < 20% r.h.) and exposed for 24 h. Desiccation survival was positively related to the pre- exposure treatment of nematodes on agar. Survival rates were 0, 3, 70, and 90% of nematodes pre-exposed for 0, 2, 5, and 12 h on the agar plate, respectively. All nematodes pre-exposed for 24 h or more revived immediately after rehydration following the desiccation treatment, irrespective of whether their postures either remained coiled or were un-coiled arti cially. 240 Characterisation of feeding and digestion in Meloidogyne incognita Jane S HINGLES ¤ , Catherine J. L ILLEY and Howard J. A TKINSON Biology Department, University of Leeds, Leeds, LS2 9JT, UK ¤ bgyjh@leeds.ac.uk The digestive proteinases of plant-parasitic nematodes have been the target of a successful proteinase inhibitor- based transgenic defence. Characterisation of the target enzymes of cyst nematodes led to the isolation of genes encoding cysteine, serine and aspartic proteinases from female cDNA libraries. To extend the work to the root- knot nematode Meloidogyne incognita , a cDNA library was constructed from feeding female nematodes. cDNA fragments corresponding to proteinases were ampli ed by PCR using degenerate primers and were subsequently used to screen the library to obtain full-length clones. cDNA clones encoding three cysteine, two serine and one aspartic proteinase have been identi ed, some of which are predicted to be extracellular. The expression patterns of the genes have been characterised by northern analysis and in situ localisation,showing varying expression patterns at different stages of development. A cysteine proteinase inhibitor expressed transgenically in Arabidopsis and potato has been shown to have a detrimental effect on M. incognita . The effect of serine proteinase inhibitors and inhibitor combinations is now being tested. 241 Variation in the assimilation and transpiration rate in nine accessions of Passi ora inoculated with Rotylenchulus reniformis Zoraida H. S UÁREZ 1 ; ¤ , Ligia Carolina R OSALES 1 , Mercedes A ZKUE 2 and María Alejandra G ÓMEZ 2 1 Instituto Nacional de Investigaciones Agrícolas, CENIAP, Protección Vegetal 2 Agrometereología, Apdo 4653, Maracay 2101, Aragua, Venezuela ¤ zsuarez@telcel.net.ve Seeking resistance to Rotylenchulus reniformis, nine accessions (236-2, 221, 214-1, 247-2, 241, 232-1, 219- 1, 219-2) of Passi ora edulis f. avicarpa and 231 of P. quadrangularis from the germplasm collection of CENIAP were evaluated. Only accession 219-1 showed a susceptibility reaction. An experiment to study the variation in the assimilation and transpiration rates between control and R. reniformis inoculated plants was carried out. In order to estimate the assimilation and transpiration rate, four measurements were made on each material with an infrared gas analyser (IRGA). Results demonstrated that all accessions showed a different behaviour in the assimilation and transpiration rate between control and inoculated plants, except accessions 247-2 and 231 where plants in both treatments exhibited similar responses. Preliminary results indicate that even though there was a resistance reaction in eight of the materials, they behave physiologically differently in the presence of the nematode. It is necessary to continue this type of study for a longer period of time and with different levels of inoculum. 242 Effects of DL-methionine on hatching and survival of Meloidogyne incognita Miguel T ALAVERA 1 ; ¤ and Takayuki M IZUKUBO 2 1 Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturaes, CSIC, C/. José Gutiérrez Abascal, 2, 28006 Madrid, Spain 2 Department of Entomology and Nematology, National Agricultural Research Center, 3-3-1 Kannondai, Tsukuba, Ibaraki, 305-8666 Japan ¤ migtalrub@yahoo.es Several concentrations of DL-methionine in vitro and applied to soil were tested in the laboratory for their effects on Meloidogyne incognita egg hatching and juvenilesurvival. Solutionsof 2 : 5 £ 10 2 mg per ml reduced egg hatching in vitro after 2 days of treatment. After 7 Vol. 4(2), 2002 207</p>
<p>Physiology (222-243) days in methionine solutions, proportion of hatched eggs were reduced by 23.3% in 2 : 5 £ 10 ¡ 1 mg/ml and by 76.4% in 2 : 5 £ 10 4 mg/ml methionine concentrations, compared to controls in distilled water. An effect of methionine solutions on juvenile activity was also shown after 24 h when percentage of active juveniles was reduced from 99.3% in controls to 83.0% in 2 : 5 £ 10 4 mg per ml treatment. Further reductions were observed at lower methionine concentrations as time of exposure increased. When methionine was applied to soil infested by M. incognita , reductions in egg hatching and juvenile activity were observed at 0.1 and 1 mg of methionine per g of soil, either in sand or clay-loam soils. The percentage of hatched eggs 1 week after methionine application was lower in sandy than in clay-loam soils. Active juveniles were not found after 1 week in soil containing 1 mg of methionine per g of soil. 243 Effects of plant secondary metabolites on plant parasitic nematodes Nathalie W UYTS ¤ , Annemie E LSEN , László S ÁGI , Dirk D E W AELE and Rony S WENNEN Laboratory of Tropical Crop Improvement, Kasteelpark Arenberg 13, 3001 Leuven, Belgium ¤ nathalie.wuyts@agr.kuleuven.ac.be Plant secondary metabolism is responsible for the produc- tion of three general groups of metabolites, avonoids, terpenoids and alkaloids, with diverse functions in plants, including defence against pathogens. The aim of the study was to test members of the three groups of metabolites for their effects on plant parasitic nematodes. The nema- tode species studied included the migratory endoparasites Pratylenchus penetrans and Radopholus similis and the sedentary endoparasites Meloidogyne incognita and Glo- bodera rostochiensis . The nematodes were subjected to in vitro toxicity tests, chemotaxis tests and tests for the inhi- bition of egg hatch. Results indicate that the avonoids juglone, caffeic acid and umbelliferone are toxic to P. penetrans with LD 50 values of 90, 374 and 418 ppm re- spectively after 72 h exposure. The monoterpenoid thy- mol and the sesquiterpenoid rishitin have LD 50 values of 395 and 387 ppm after 24 h exposure. Both caffeic acid and rishitin repel P. penetrans and R. similis at concen- trations as low as 50 and 20 ppm in the chemotaxis tests. Other avonoids with repelling effects include quercetin (20 ppm), resveratrol (100 ppm), kaempferol (100 ppm) and genistein (100 ppm). 208 Nematology</p>
<p>Poster sessions 244 The susceptibility of cucurbitaceous plants to Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 Tímea Á CS 1 ; ¤ , Béla P ÉNZES 1 , Mariann E LEKES 2 , Antal F ERENCZY 1 and József F AIL 1 1 Szent Istvan University, Faculty of Horticultural Sciences, Ménesi út 44, 1118 Budapest, Hungary 2 Central Service for Plant Protection and Soil Conservation, Laboratory for Pest Diagnosis, Budaörsi út 141-145, 1118 Budapest, Hungary ¤ timeaa@hotmail.com Meloidogyne incognita is an important pest of forced cucumber. As there are no cucumber varieties resistant to Meloidogyne incognita , the use of cucumber plants grafted onto tolerant cucurbit species offers a highly effective, as well as an environmentally friendly means of control. Two cucurbit species, Sycios angulatus Harry and Cucurbita cifolia , have been used by Hungarian growers as rootstock for cucumber. However, the tolerance level of these two species against M. incognita has not been fully elucidated. These two species, along with eight other previously untested species belonging to the Cucurbitaceae , were evaluated for their resistance to M. incognita. Tests were carried out under glasshouse conditions. The damage caused on the roots was assessed by using two six-graded scales (measuring size of galls and number of galls). Stochastic homogeneity test was used for statistical analysis. We found that the galls formed on the roots of S. angulatus Harry were small but abundant. Galls occurring on the roots of C. cifolia were not only abundant but also large. Three cucurbit plants, Cucurbita pepo Alba, Cucurbita pepo Sárga óriás and Cucurbita moschata Orange, were identi ed as potential rootstocks for glasshouse cucumber. 245 Nematode losses in cotton in the USA Donald J. B LASINGAME 508 Colonial Circle , Starkville, MS 39759, USA Db508pb@aol.com Cotton is grown on more than 15 million acres in 17 states in the United States. Plant parasitic nematodes have been found in every state where cotton is grown. Each year losses to diseases and nematodes are reported to the National Cotton Council by plant pathologist and nematologist in each state where cotton is grown. Compared to other plant diseases, nematodes are the largest cause of yield loss. In 2001 plant-parasitic nematodes accounted for an estimated loss of 979 357 bales valued at 381.9 million dollars. Root-knot was responsible for a loss of US$200.5 million, reniform for US$154.5 million, and other species for US$25.5 million loss. Beltwide losses due to nematodes have increased more than 50% in the past 10 years. Most experts say that economic losses have probably been underestimated in the past when losses due to nematodes were erroneously attributed to poor soil fertility, pH, or ‘weak elds’. Improvements in properly identifying nematode damage have been made, thus impacting the perceived trend of increased losses due to these pests. 246 Meloidogyne incognita , a new threat to soybean production in Illinois Jason B OND ¤ , Michael S CHMIDT , Alan W ALTERS and John R USSIN Plant, Soil and General Agriculture, Southern Illinois University Mailcode 4415, Carbondale, IL 62901-4415, USA ¤ jbond@siu.edu Meloidogyne incognita is an emerging threat to crop production in southern Illinois. This pathogen has been identi ed in six soybean elds, eight vegetable elds and in ve peach orchards. The potential impact of M. incognita to soybean germplasm in northern latitudes is unknown. In 2001, four soybean varieties (Pioneer 9481, Pioneer 9492, Gateway 493 and LS 94-3207) were selected and planted in infested elds. Nematode population densities were recorded at planting and every 6 weeks until harvest. At planting, the population density of M. incognita averaged eight juveniles/100 cm 3 soil. Reproduction by M. incognita was higher in the plots planted to P 9481. At harvest, the population densities (juveniles/100 cm 3 soil) were 508, 41, 37 and six for P 9481, P 9492, GW 493 and LS 94-3207, respectively. Across the four varieties, the increase in the population density of M. incognita was concomitant with a linear decrease in soybean yield. 247 Host suitability and damage thresholds of arable crops to the root lesion nematode Pratylenchus penetrans E. B ROMMER , T. VAN B EERS and L.P.G. M OLENDIJK ¤ Applied Plant Research (PPO agv), P.O. Box 430, 8200 AK Lelystad, The Netherlands Vol. 4(2), 2002 209</p>
<p>Pathogenicity (244-264) ¤ L.P.G.Molendijk@ppo.dlo.nl Root lesion nematodes ( Pratylenchus penetrans ) are of growing concern in Dutch arable farming. Especially on the light sandy soils damage occurs in potatoes, black root and carrots. Dutch farmers try to prevent the problems by choosing a non-host as preceding crop to vulnerable crops. Most data on host status and damage thresholds were determined in the 1950s and 1960s. PPO started in 1998 to reconsider the multiplication of P. penetrans on new crops and varieties within modern growing practices. The poster presents the host status of important arable- and green manure crops determined in eld- and in pot experiments. In addition, eld results of initial populations( Pi ) and crop yield are shown for some arable crops. 248 Effect of the root-knot nematode Meloidogyne incognita on the yield of parsley ( Petroselinum crispum ) R. C ROZZOLI 1 ; ¤ , Aguirre Y NDIRA 1 and N. G RECO 2 1 Universidad Central de Venezuela, Facultad de Agronomía, Instituto de Zoología Agrícola. Apdo. 4579, Maracay, Venezuela 2 Istituto per la Protezione delle Piante, Sezione di Bari, C.N.R., 70126 Bari, Italy ¤ rencro@telcel.net.ve A screenhouse experiment was conducted in 1000 cm 3 plastic pots to evaluate the effect of increasing population densities of M. incognita on yield of parsley. Initial nematode densities were: 0, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, 128, 256 and 512 eggs C second stage juveniles (J2)/cm 3 soil. The Seinhorst model, y D m C . 1 ¡ m/z P i ¡ T , was tted to average plant top and total fresh weight and top dry weight. Tolerance limits ( T ) to the nematode for top fresh weight, total fresh weight and top dry weight were 0.17, 0.02 and 0.05 eggs C J2/cm 3 soil, respectively. The minimum relative yields ( m ) were 0.5 at Pi > 16 eggs C J2/cm 3 soil, 0.55 at Pi > 2 eggs C J2/cm 3 soil and 0.4 at Pi > 4 eggs C J2/cm 3 soil for top fresh weight, total fresh weight and top dry weight, respectively. The maximum nematode reproduction rate was 37-fold at Pi D 0.25 eggs C J2/cm 3 soil and the equilibrium density was 5 eggs C J2/cm 3 soil. 249 Reniform nematodes – a threat to cotton production in Alabama (USA) William G AZAWAY 104 Extension Hall, Auburn University, AL 36849, USA wgazaway@bellsouth.net Reniform ( Rotylenchulus reniformis ) and root-knot ( Me- loidogyne incognita ) are the two major nematode species that attack cotton in Alabama. Nematode samples from Auburn’s nematode analytical laboratory and two statewide nematode surveys conducted in 1990/1991 and again in 1999/2000 revealed that reniform is the most widespread and damaging nematode species in Alabama. This species is responsible for over 90% of the nema- tode damage on cotton in the state. Twenty-one percent of the cotton elds sampled in north Alabama and 26% of elds in central Alabama have reniform populations greater than 500 juveniles/100 cm 3 soil. Yield losses in a cotton eld with high reniform populationscan be as lit- tle as 10% or as high as 75%, depending on the presence of favourable or adverse growing conditions in any given year. When growing conditions for cotton in Alabama are normal, yield losses usually average around 30-40%. Statewide yield losses during the years 1999, 2000 and 2001 were estimated to be US$14 million annually. Most cotton producers use nematicides to successfully manage reniform in cotton. A 1-year rotation with a non-host crop in Alabama has been shown to be more effective than a nematicide. However, most Alabama growers, who pre- fer to grow cotton continuously in the same elds, have not adopted this practice. Reniform resistant or tolerant commercial cultivars are not currently available. Research continues for more effective crop rotation schemes, im- proved nematicide application techniques and the search for reniform resistance in commercial cotton cultivars. 250 Investigations on Ditylenchus dipsaci damaging carrot in Italy Nicola G RECO 1 , Antonio B RANDONISIO and Piero B ONCORAGLIO 2 1 Istituto per la Protezione delle Piante, Sezione di Bari, C.N.R., Via G. Amendola 165/A, 70126 Bari, Italy 2 Sezione Operativa 33, Assessorato Reg. Agr. e Foreste, Regione Siciliana, Via C. Ciano 39, 97014 Ispica (RG), Italy nemang02@area.ba.cnr.it Investigations were undertaken in southern Italy on the epidemiology of an Apulian and a Sicilian population of Ditylenchus dipsaci , on carrot under eld conditions,from September to the following March. The host status of some plants to the Sicilian population of the nematode 210 Nematology</p>
<p>Poster sessions was also assessed. In Apulia, on carrot sown in early September, the nematode infection started at the end of October on leaves and in early December on tap roots. Death of leaves and tap root rot were observed the following January on mature plants. On carrot sown 1 month later nematode infection occurred by the beginning of November and greatly suppressed plant growth. In Sicily, on carrot sown in early October the infection was obvious on aerial plant parts at the end of November and on tap roots in mid December. Leaf death and tap root rot occurred at end of January. Early symptoms of nematode attacks were straddled leaves, multi-bud plant crowns and light discolorations of tap root tops. The portion of the plant most affected by D. dipsaci was that 2-4 cm below and above ground. The Sicilian population of the nematode reproduced on carrot, broad bean, oats, rye, Italian ryegrass, celery, Amny majus and Galium aparine . 251 Effect of Globodera rostochiensis on the yield of potato cv. Kennebec in Venezuela N. J IMÉNEZ -P ÉREZ 1 , R. C ROZZOLI 2 and N. G RECO 3 1 Universidad Centrooccidental Lisandro Alvarado, Facultad de Agronomía, Barquisimeto, Venezuela 2 Universidad Central de Venezuela, Facultad de Agronomía, Instituto de Zoología Agrícola, Apdo 4579, Maracay, Venezuela 3 Istituto per la Protezione delle Piante, Sezione di Bari, C.N.R., 70126 Bari, Italy The relationship between initial densities ( Pi ) of Glo- bodera rostochiensis pathotype Ro2 and yield of the sus- ceptible potato cultivar Kennebec was investigated in 30 dm 3 microplots at Cubiro, Lara State, during the January- April growing season. Pi used were 0, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32, 64, 128, and 256 eggs/cm 3 soil. Tuber yield response to Pi tted the model y D m C . 1 ¡ m/z P i ¡ T and a tolerance limit ( T ) of potato to G. rostochiensis of one egg/cm 3 soil was derived. Yield losses of 20 and 50% oc- curred at Pi of eight and 32 eggs/cm 3 soil, respectively. The minimum relative yield ( m ) was 0.35 at Pi > 128 eggs/cm 3 soil. The maximum nematode reproduction rate was 25-fold at Pi D 0 : 125 eggs/cm 3 soil and the equilib- rium density 64 eggs/cm 3 soil. Symptoms of the nematode attack became obvious on aerial plant parts at Pi D 64 eggs/cm 3 soil. 252 Parasite-host relationship and virulence of the most damaging nematodes in elds in Armenia J. K ARAPETYAN ¤ and H. M KRTCHJAN Institute of Zoology, NAS RA, Yerevan, , P. Sevak 7, Armenia ¤ zang@cornet.am We have studied the roots and the top-soil under tomatoes, cucumbers, pepper, cabbage, carrot and watermelon as well as wheat, sweetcorn and potato. Thirty-nine species of nematodes recorded in ten crops belonged to 17 genera. The most virulent included Macropostonia xenoplax, Criconemoides mongolensis, Heterodera crucifera, Glo- bodera rostochiensis, Meloidogyne hapla, M. arenaria, M. incognita, Tylenchorhynchus brassica, T. davaini, T. parvus, Quiniculcius acti, Helicotylenchus pseudorobus- tus, H. eritrinae, H. conicephalus, H. californicus, H. digonicus, Ditylenchus destructor, D. dipsaci, Aphelen- choides subparientinus, A. ritzemabosi, Longidorus elon- gatus and others. The nematode fauna of crops studied was diverse and abundant, and was distinguished by a large number of dominant species. The species diversity of nematodes and their population density in the top soil was related to the agrotechnology measures which low- ered the number of species. 253 Pathogenicity of Pratylenchus coffeae on seedlings of coffee cv. Mundo novo Roberto K. K UBO 1 ; ¤ , Rosangela A. S ILVA 2 , Melissa D. T OMAZINI 2 , Claudio M.G. O LIVEIRA 1 , Paulo M AZZAFERA 3 and Mário M. I NOMOTO 2 1 Instituto Biológico, CP 70, 13001-970 Campinas, SP, Brazil 2 ESALQ/USP, CP 9, 13418-900 Piracicaba, SP, Brazil 3 UNICAMP, CP 6109, 13083-970 Campinas, SP, Brazil ¤ kubo@biologico.br The pathogenicity of two Brazilian Pratylenchus coffeae isolates was evaluated in two glasshouse experiments on coffee seedlings ( Coffea arabica ) cv. Mundo Novo. In the rst, the effect of initial population densities ( Pi D 0, 333, 1000, 3000 and 9000 nematodes/plant) was studied using P. coffeae isolate from Marília, SP. The data were tted to the Seinhorst model. At 270 days after inoculation, all plants inoculated with 9000 nematodes and the majority inoculated with 3000 nematodes were dead. Plant growth and photosynthesis were reduced with inocula of 333 and 1000 nematodes, respectively. In the second experiment, pathogenicity of two P. coffeae isolates (from Marília and Rio de Janeiro) was compared using coffee seedlings. Although photosynthesis was similarly reduced for both isolates with an inoculum of 8000 nematodes/plant, the Marília isolate caused intense darkening of the roots, leaf chlorosis and a greater reduction of root and shoot growth. Vol. 4(2), 2002 211</p>
<p>Pathogenicity (244-264) In both experiments, reproduction ( Pf/Pi ) of the isolates was low, suggesting that coffee is a poor host for both P. coffeae isolates. The differential pathogenicity observed in the second experiment supports previously published data that reported differences in morphology and host ranges between these isolates. 254 Virulent populations of Meloidogyne in vegetable crops from Uruguay J. Antonio L ÓPEZ -P ÉREZ 1 ; ¤ , Leonardo DE L EÓN 2 and Antonio B ELLO 1 1 Dpto de Agroecología. Centro de Ciencias Medioambientales, CSIC, Serrano 115 dpdo, 28006 Madrid, Spain 2 Dpto Agricultura, Rel-UITA, W. Ferreira Aldunate 1229, C.P. 11.100, Montevideo, Uruguay ¤ pezperez@ccma.csic.es Some tomato varieties that are carriers of the Mi gene, which confers resistance on them to the root- knot nematodes Meloidogyne arenaria and M. incognita , appeared severely affected by these pathogens, making the crop non-viable in many cases. This happens frequently in the departments of northern Uruguay, especially Salto and Artigas, where soil temperatures often rise above 27 ± C, which is one of the main causes for the break in resistance. Various M. incognita populations from northern Uruguay have been characterised, proving to be virulent to resistant tomato varieties. Several pepper cultivars with the N gene have also been selected that demonstrate resistance to these nematodes. It can be af rmed that conventional crop methodologies are contributing to the selection of virulent populations, which could make the use of resistant varieties impossible in the future. Biofumigation and other crop techniques proved effective in the regulation of virulent nematode populations of the Meloidogyne genus, without the use of nematicides. 255 Virulent populations of Meloidogyne in vegetable crops in Spain J. Antonio L ÓPEZ -P ÉREZ ¤ , Miguel E SCUER and Antonio B ELLO Dpto de Agroecología, CCMA, CSIC, Serrano 115 dpdo, 28006 Madrid, Spain ¤ pezperez@ccma.csic.es It has been observed that tomato varieties having the Mi gene and pepper varieties with the N gene, which confers resistance on them to the root-knot nematodes Meloidogyne arenaria, M. incognita and M. javanica , are seriously affected by these pathogens, even leaving the crop non-viable in some cases. It has been observed that plants resistant to these nematodes, either because they are carriers of the above-mentioned gene or because they are grafted onto a resistant stock, are susceptible principally to attacks by M. incognita and M. javanica . In most cases, this is due to a incorrect application of these alternatives, sometimes because the plant loses its resistance due to exposure to soil temperatures over 27 ± C or by selection of virulent populations. The use of crop management techniques that decrease nematode populations, such as biofumigation, has been regarded as ef cient in the regulation of virulent populations of nematodes belonging to the genus Meloidogyne . 256 Pest risk analysis of Meloidogyne chitwoodi in Norway Christer M AGNUSSON ¤ , Leon T HIJSEN and Ricardo H OLGADO The Norwegian Crop Research Institute Plant Protection Centre, Department of Entomology and Nematology, Høgskoleveien 7, N-1432 Aas, Norway ¤ christer.magnusson@planteforsk.no Meloidogyne chitwoodi may be introduced into Norway through plant material and soil. The nematode may easily establish on common crop plants. During the growing season two generations are expected to develop in southern Norway, while conditions in the central parts would allow for the development of one generation. M. chitwoodi starts to develop at 5 ± C. Planting and sowing in Norway starts when soil temperatures reach around 4 ± C. The use of plastic tunnels to increase soil temperature is a common practice in early potatoes and vegetables, and would enhance nematode development. M. chitwoodi requires 600-800 degree days (DD) to complete one generation from the time of planting, and 500-600 DD for subsequent generations. These temperature sums are commonly recorded in potato growing areas of Norway. Qualitative damage on potato tubers would require the re- infection and development of the second generation, and is expected in the southern areas. Qualitative damage on carrots does not require re-infection, and is expected also in central parts. The possibility that the nematode could cause damage to other vegetables and to cereals is an additional concern that supports its status as a quarantine pest organism. 212 Nematology</p>
<p>Poster sessions 257 Progress of two kinds of symptom appearing in the body of recovered Pinus thumbergii from pine wilt disease Kuniaki M ATSUURA Forestry and Forest Products Research Institute, Matsunosato 1, Kukizaki, Ibaragi 305-8687, Japan Pine wood nematode can cause fatal damage to Japanese black pine, Pinus thumbergii and red pine, Pinus densi ora . However, not enough is known about the mechanisms leading to the death of pines killed by this organism. Hence, study of the various aspects of pine trees which are purported to represent the processes of the disease from its early stages through to its lethal stages has helped to clarify both disease development and causal mechanism. Thionazin or mesulfenfos was injected into 11-year-old P. thumbergii infected with pine wilt disease following inoculation of pine wood nematodes 2, 5 and 6 weeks prior to treatment with nematicides. At the time of injection with nematicides, all the trees tested were judged as having pine wilt disease because they had ceased to exude pine resin. Recovery, expressed as resumation of resin exudation by surviving trees, was observed in pines injected with thionazin 2 weeks after inoculation. By examining cross-sections of recovered pine trees felled 2 years after this experiment, two apparently distinct symptoms were observed, one an early symptom associated with the formation of small non-water-conducting patches, and the other associated with cambium death. Both symptoms seemed to begin in and progress from the pith. 258 Impact of Meloidogyne graminicola on yield of lowland rainfed rice in Bangladesh Jon P ADGHAM 1 ; ¤ , George A BAWI 2 , John D UXBURY 1 and Abdul M AZID 3 1 Department of Crop and Soil Sciences 2 Department of Plant Pathology, Cornell University, Ithaca, NY 14853, USA 3 Bangladesh Rice Research Institute, Rajshahi, Bangladesh ¤ jlp39@cornell.edu Replicated plots with and without the application of Fu- radan 5G (40 kg/ha) were established at an agricultural research station and on farmer elds in northwestern Bangladesh to assess the impact of Meloidogyne gramini- cola on lowland rainfed rice yield in the rice-wheat pro- duction system. At the research station, rice yields in- creased by 0.2, 0.8 and 1.1 t/ha where Furadan was ap- plied to the seedbed only, to the eld only, and to both the seedbed and eld, respectively, compared to a non-treated control. Averaged across three farmer elds, rice yield in- creased by 1.1 t/ha where Furadan was applied to both the seedbed and eld compared to the control. At harvest, soil levels of M. graminicola in the non-treated plots were more than three times greater than those in the treated plots at both locations. Prior to transplanting, seedling shoot height and dry weight were signi cantly greater, and soil levels of M. graminicola signi cantly less, in the treated seedbed plots compared to the non-treated plots. This is the rst on-farm study to demonstrate a negative impact of M. graminicola on rice growth and yield during the monsoon season in Bangladesh. 259 Reaction of olive to Pratylenchus vulnus infections in Italy Nicola S ASANELLI ¤ and Trifone D ’A DDABBO Istituto per la Protezione delle Piante, Sezione di Bari, C.N.R., Via G. Amendola 165/A, 70126 Bari, Italy ¤ nemans13@area.ba.cnr.it The reaction of seven olive cultivars, Cellina di Nardò, Cima di Bitonto, Coratina, FS 17, Frantoio, Leccino and Yusti and of the rootstock DA 12 I to Pratylenchus vulnus infections was evaluated in a glasshouse experiment. Plants were arti cially inoculated with 200 nematodes per pot. Plant growth and nematode reproduction parameters were recorded. Host reaction was rated according to the reproduction factor r D Pf / Pi . All the tested cultivars and rootstock were good hosts for P. vulnus , although the highest susceptibility was shown by FS 17. No statistical difference was found among the P. vulnus reproduction parameters on the other cultivars. 260 Impact of Pratylenchus neglectus infestation on wheat in Western Australia Shashi S HARMA ¤ , Sean K ELLY and Robert L OUGHMAN Department of Agriculture, Baron Hay Court, South Perth, WA 6151 Australia ¤ ssharma@agric.wa.gov.au Pratylenchus neglectus is very widespread in cereal- producing regions of Western Australia. A recent study revealed that the average nematode population in 64% of the surveyed locations exceeded the lowest level that causes signi cant yield loss. Experiments were Vol. 4(2), 2002 213</p>
<p>Pathogenicity (244-264) established between 1999 and 2001 in nematode-infested elds at ve locations in central and southern wheat- belts to study impact of the nematode on performance of wheat. Large plots (1 : 8 £ 40 m or 1 : 44 £ 20 m) were sown to susceptible wheat (cvs Machete or Cunderdin or Brookton). In half of the 64 plots (paired plots), aldicarb (Temik 150G) was applied (20-30 kg/ha) at seeding. Ten weeks after sowing nematode densities in roots were assessed. Nematode density and wheat yield in the nematicide-treated and check plots were compared using analysis of variance. Aldicarb partially controlled the nematode populations. Yield enhancement with nematicide application was 6-14%. At one location, yield differences following use of aldicarb were not signi cant, partly due to inadequate nematode control. The study established economic damage potential of P. neglectus in Western Australia; however, this loss assessment could be an under-estimation of actual loss as nematicide provided only partial protection to plants from nematode infection. 261 Population dynamics of, and yield loss caused by, Pratylenchus neglectus and P. thornei in cereal crops in Australia Sharyn T AYLOR 1 ; ¤ , Kerrie D AVIES 2 and Danuta S ZOT 1 1 South Australian Research and Development Institute, GPO Box 397, Adelaide, South Australia 5001, Australia 2 Adelaide University, Department of Applied and Molecular Ecology, PMB 1 Glen Osmond, SA 5064, Australia ¤ taylor.sharyn@saugov.sa.gov.au A range of initial soil densities of either P. neglectus or P. thornei was established in eld sites in South Australia. This was achieved by growing replicated plots of susceptible wheat (cvs Machete and Spear), moderately resistant wheat (cv. Excalibur), moderately resistant barley (cv. Chebec) and resistant triticale (cv. Tahara) in the 1st year. In the 2nd year, these cultivars resulted in initial P. neglectus densities for Machete, Spear, Excalibur, Chebec and Tahara of 18, 8, 4, 2 and 3/g soil, respectively. For P. thornei , these cultivars resulted in initial densities of 14, 10, 3, 1 and 1/g soil. Plots were oversown in the 2nd year with an intolerant oat cultivar (Echidna). Initial ( Pi ) and nal numbers ( Pf ) of nematodes were assessed from soil of all plots in each year. For both P. neglectus and P. thornei , a signi cant negative linear relationship was observed between yield of the intolerant oat and initial nematode density in the 2nd year. Yield losses of 27% for P. neglectus and 22% for P. thornei were estimated. In addition, an exponential relationship was observed between initial density and nematode multiplication rate ( Pf/Pi ). 262 Infection of Arachis hypogaea by Meloidogyne arenaria may increase a atoxin contamination of kernels P. T IMPER ¤ and D.M. W ILSON USDA ARS and Department of Plant Pathology, University of Georgia, P.O. Box 748, Tifton GA 31793, USA ¤ ptimper@tifton.cpes.peachnet.edu A eld-microplot study was conducted to determine whether a atoxin levels in peanut, Arachis hypogaea , were correlated with pod and root galling caused by Meloidogyne arenaria ( Ma ). The experiment was a completely randomised 2 £ 2 factorial with six replicates per treatment. Factors were nematodes, plus and minus Ma , and fungus, plus and minus Aspergillus avus ( Af ). Peanut seedlings, either infected with Ma or uninfected, were transplanted into 2.3 m 2 plots previously fumigated with methyl bromide. Inoculum of Af was sprinkled over the plant canopy at mid bloom. Drought was induced after pod set by covering plots during rain with a breglass shelter. Pod- and root-gall indices (1-5 scale) were determined for all plants in the plot and averaged. Pods from each plot were bulked, shelled, and a subsample of kernels was used to determine a atoxin concentration and percentage colonised by Af . Neither factor, nematodes or fungus, affected a atoxin concentration; however, there was an interaction between these factors ( P D 0 : 003). In plots without added fungus, there was a correlation between a atoxin concentration vs pod-gall index ( P D 0 : 001, r D 0.82) and vs root-gall index ( P D 0 : 006, r D 0.74). Colonisation of kernels by Af increased with increasing pod galling ( P D 0 : 04, r D 0.42). 263 Yield losses of barley, oat and wheat due to root lesion nematode in South Australia Vivien A. V ANSTONE 1 ; ¤ , Michelle H. R USS 1 ; 2 and Sharyn P. T AYLOR 2 1 University of Adelaide, Department of Plant Science, PMB 1, Glen Osmond, 5064, South Australia, Australia 2 South Australian Research and Development Institute, GPO Box 397, Adelaide, 5001, South Australia, Australia ¤ vivien.vanstone@adelaide.edu.au 214 Nematology</p>
<p>Poster sessions Wheat ( Triticum aestivum ) is the principal host of Praty- lenchus neglectus in southern Australia. By comparison, barley ( Hordeum vulgare ) and oat ( Avena sativa ) are mod- erate hosts. Mean yield loss for intolerant wheat in 1995- 1998 was 15-20%. Trials at six sites were assessed in 2000 to compare losses for barley, oat and wheat. Natural vari- ation in nematode density between and within trial sites allowed comparison of plot yields over a range of ne- matode densities. Final nematode density ( Pf ) was deter- mined during grain developmentin mid-spring (October). Negative correlations between yield and Pf were signi - cant for barley ( r D 0 : 789-0.875), oat ( r D 0 : 654-0.892) and wheat ( r D 0 : 524-0.828). Yield loss for each geno- type was calculated from the maximum genotype yield predicted by the linear relationship between yield and Pf. Mean yield loss for intolerant barley and oat was 8.4%, and for wheat 7.3%. Barley and oat are more resistant than wheat ( Pf , respectively, 1.0, 1.6 and 2.5 P. neglectus /g dry soil), but suffer comparable yield loss and are therefore as intolerant as wheat. Pratylenchus neglectus is a constraint to cereal production in southern Australia, and these yield penalties represent signi cant nancial loss to the grower. 264 Response of four potato ( Solanum tuberosum ) cultivars to varying levels of root-knot nematode ( Meloidogyne hapla ) inoculum Luciana M. V ILLANUEVA ¤ and Maidina A. L INGGOY Department of Plant Pathology, College of Agriculture, Benguet State University, La Trinidad, Benguet 2601, Philippines ¤ lucy@bgo.csi.com.ph The effect of varying levels of Meloidogyne hapla inoculum on the growth and yield of four potato cultivars was studied under glasshouse conditions. Plant height, fresh root and top weights, and tuber yield were signi cantly affected by the nematode. Plant height was reduced by 28-45% when Pi was 1000 juveniles per pot, and 30-57% when the number of infective juveniles present around young seedlings was 10 000. Fresh root weight was decreased by 35-44, 39-51, 41-50 and 37- 46% in cvs Berolina, Igorota, Solibao and Granola, respectively, when Pi was 1000-10 000. Signi cant yield reduction was also noted in the four cultivars used when Pi was 1000-10 000 juveniles per pot: 44-56% in Berolina; 75-88% in Igorota and Solibao and 85- 100% in Granola. Based on the gall index rating used, cvs Berolina, Igorota, Solibao and Granola were rated resistant, moderately resistant, moderately susceptible and susceptible, respectively, to M. hapla infection. Vol. 4(2), 2002 215</p>
<p>Parasitism (265-294) 265 Novel gene discovery in plant-parasitic nematodes Bryony B ANKS ¤ , Miles A RMSTRONG , John J ONES , Mark P HILLIPS and Vivian B LOK Plant Pathogen Interactions, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK ¤ bbanks@scri.sari.ac.uk The potato cyst nematodes ( Globodera pallida and G. rostochiensis ) are economically important pests both in the UK and worldwide, and cause signi cant losses to commercial potato production. As a means of investigating the complex host-pathogen interactions involved in G. pallida and G. rostochiensis infections, cDNA AFLP and suppression subtractive hybridisations (SSH) using resistant and susceptible potato cultivars were carried out. Novel genes expressed during invasion of the host plant and subsequent nematode development were identi ed by harvesting plants at several time points ranging from 24 h to 14 days post-infection. A signi cant proportion of candidate genes from the SSH matched nematode EST such as FABP-1, haemolysin, calponin, beta-1,4-endoglucanase,cytochrome p450 monoxygenase and ribosomal proteins. Other sequences gave no reliable database matches. Localisation studies are being carried out on these genes by in situ hybridisation to obtain functional information and levels of gene expression during nematode invasion and development are being investigated using rt -PCR and southern blot analysis. To further quantify levels of expression during the host- pathogen interaction an analysis using real time PCR is currently underway. 266 Cloning of the chorismate mutase homolog of the soybean cyst nematode Heterodera glycines Sadia B EKAL ¤ , K.N. L AMBERT and T.L. N IBLACK Dept of Crop Science, University of Illinois, Urbana, IL 61801, USA ¤ sbekal@uiuc.edu The chorismate mutase is a nematode gland secreted protein that was rst cloned from root-knot nematode Meloidogynejavanica . This enzyme is extensivelystudied in root-knot nematode and it was recently reported as an EST from Globodera rostochiensis. This enzyme is believed to be involved in nematode parasitism. Using degenerate primers to the conserved regions of both known nematode chorismate mutase proteins, we successfully ampli ed the chorismate mutase of Heterodera glycines , the soybean cyst nematode (SCN), from cDNA extracted from 4-day-old parasitic juveniles. The SCN homolog gene has been cloned and sequenced. The derived protein sequence of the SCN chorismate mutase showed about 25% identity to that of M. javanica and about 55% identity to that of G. rostochiensis . The SCN chorismate mutase is being characterised by southern blot, enzymatic analysis and in situ hybridisation analysis. 267 Establishing a Lotus japonicus -nematode pathosystem to search for variations in their interactions Héctor C ABRERA P OCH 1 ; ¤ , Andrew W ARRY 1 and Charles O PPERMAN 2 1 Nematode Interactions Unit, Plant-Pathogen Interactions Division, IACR-Rothamsted, Harpenden, Herts AL5 2JQ, UK 2 Department of Plant Pathology and Genetics, North Carolina State University, Raleigh, NC 27695, USA ¤ hector.cabrera@bbsrc.ac.uk In order to complete their life cycles, both root-knot and cyst nematodes must interact with their host plants. Much attention has been devoted to the nematode factors involved in root penetration, migration and feeding site formation. However, very little is known about plant host factors that are needed for the susceptible interaction to occur because, in general, natural host plants are not easy to manipulate genetically. Lotus japonicus has emerged in the past few years as a suitable model plant to study interactions with nitrogen xation symbionts. A set of genetic resources and tools are rapidly becoming available for L. japonicus , including ecotypes, mutants, transformation procedures and a sequencing project. We have established a pathosystem using Lotus japonicus as a host plant for both a plant cyst nematode and a root-knot nematode. The current search for variation in the interactions between either of these nematodes and a battery of L. japonicus ecotypes and mutants will eventuallylead to the isolation and cloning of plant factors responsible for such interactions. 268 Isolation of putative parasitism genes from Globodera pallida Héctor C ABRERA P OCH 1 ; ¤ , Andrew W ARRY 1 and Charles O PPERMAN 2 216 Nematology</p>
<p>Poster sessions 1 Nematode Interactions Unit, Plant-Pathogen Interactions Division, IACR-Rothamsted, Harpenden, Herts AL5 2JQ, UK 2 Department of Plant Pathology and Genetics, North Carolina State University, Raleigh, NC 27695, USA ¤ hector.cabrera@bbsrc.ac.uk Potato cyst nematodes (PCN) are devastating pests in the United Kingdom and other European countries. While Globodera rostochiensis can be controlled in the UK by using resistant potato cultivars, no effective resistant genes are available to control G. pallida populations. Research targets for the control of G. pallida include parasitism genes needed to complete its life cycle. To isolate these targets, two G. pallida cDNA libraries were built from either preparasitic juveniles (J2) and adult (gravid) females or J2 individuals. A collection of more than 1000 EST from the former library has been released into the public domain. Data mining in this collection reveals EST encoding for putative secreted proteins with similarities to Tylenchida sequences, but not to free-living C. elegans sequences, which suggests that they may have a role in plant nematode parasitism. A number of PCN speci c sequences have no homologies to other sequences in databanks. These novel sequences encode for proteins containing features of secreted proteins, which make them candidates for further research into their putative role in PCN-speci c parasitism and evolution. 269 Using monoclonal antibodies to discover parasitism proteins from the virus-vector nematode Xiphinema index Qing C HEN 1 ; ¤ , Rosane H. C URTIS 2 , Franco L AMBERTI 3 , Maurice M OENS 4 , Derek J.F. B ROWN 1 and John T. J ONES 1 1 Plant-Pathogen Interactions Programme, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK 2 Nematode Interactions Unit, IACR Rothamsted, Harpenden, Herts AL5 2JQ, UK 3 Istituto di Nematologia Agraria, C.N.R., 70126 Bari, Italy 4 Laboratory voor Nematology, Centrum voor Landbouwkundig Onderzoek, Gent, Belgium ¤ qchen@scri.sari.ac.uk Xiphinema index is a plant ectoparasitic nematode that transmits plant viruses. Xiphenema index induces changes in plant cells similar to those induced by endoparasites such as Meloidogyne spp. Xiphinema index is large and can be cultured, making it an attractive model system for some aspects of plant nematology. Although much work has been performed on the interaction between the nematode and the virus, most research on the nematode itself has been limited to taxonomic studies. Antibody methodology has been successfully used to discover parasitism genes from endoparasites. We therefore produced a panel of MAbs against X. index. A series of secreted proteins present in different dorsal ducts, which related to particular periods of the nematode feeding cycle, were recognised by one monoclonal antibody. Other MAbs were obtained which recognise the cuticle surface, muscle bres, nerve cords and oocytes. Some of these MAbs have the potential to be developed for use as nematode diagnostics. An antibody that recognises the virus-retention site within the nematode odontophore may be useful for further virus- nematode interaction studies. In future work we will use western blots of 2D electrophoresis gels coupled to MALDI-TOF analysis to identify the secretory proteins in gland cells recognised by the MAbs. 270 Peptides that bind to and inhibit cellulase of Heterodera glycines identi ed by combinatorial library screening Wanglei D U 1 ; ¤ , Richard H USSEY 3 , Thomas B AUM 2 and Eric D AVIS 1 1 Department of Plant Pathology, Campus Box 7616, North Carolina State University, Raleigh, NC, USA 2 Department of Plant Pathology, Iowa State University, Ames, IA, USA 3 Department of Plant Pathology, University of Georgia, Athens, GA, USA ¤ wanglei_du@ncsu.edu The feasibility of identifying inhibitors of the products of nematode parasitism genes is being investigated using the secreted cellulases of Heterodera glycines as a model target. The HG-eng-2 endoglucanase gene of H. glycines was overexpressed in a Pichia pastoris host, and active recombinant HG-ENG-2 was af nity- puri ed. Puri ed rHG-ENG-2 was used as a target in biopanning experiments with a commercial phage-display combinatorial 7-mer peptide library. Two stringent rounds of biopanning produced about 1000 plaques with peptides that bound to rHG-ENG-2. Individual plaques are now being investigated to determine the number of unique peptides that bind to rHG-ENG-2 and to identify those that inhibit the ability of rHG-ENG-2 to degrade carboxymethylcellulose. One promising 7-mer peptide Vol. 4(2), 2002 217</p>
<p>Parasitism (265-294) that binds to and inhibits the activity of rHG-ENG-2 has been identi ed to date. 271 Proteins and expressed genes of the ectoparasite Xiphinema index Cleber F URLANETTO ¤ , Derek J.F. B ROWN and John T. J ONES Plant-Pathogen Interactions Programme, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK ¤ cfurla@scri.sari.ac.uk Xiphinema index , the natural vector of Grapevine fan leaf virus, is a plant ectoparasite that induces changes in host cells similar to those induced by biotrophic endoparasites such as Meloidogyne and Heterodera . Xiphinema index is large, readily cultured and all life stages occur outside the plant making it an attractive model system for some aspects of plant nematology.We have begun a programme aimed at identifying genes and proteins important in the host parasite interaction of this species. Expressed sequence tags are being obtained from a mixed stage cDNA library of this nematode. Over 500 EST have been obtained and a variety of genes identi ed including proteases and collagens. To date no EST from genes acquired from bacteria by horizontal gene transfer have been found. Two-dimensional electrophoresis has been used to identify proteins speci c to nematode portions containing the pharyngeal gland cells. In future work we will use MALDI-TOF analysis coupled to the data from our EST programme to identify the genes encoding such proteins. 272 De ning a plant-parasitic nematode: a pro le of putative parasitism genes expressed in the pharyngeal gland cells of Heterodera glycines Bingli G AO 1 ; ¤ , Tom M AIER 2 , Eric D AVIS 3 , Thomas B AUM 2 and Richard H USSEY 1 Departments of Plant Pathology 1 University of Georgia, Athens, GA 30602 3 Iowa State University, Ames, IA 50011 4 North Carolina State University, Raleigh, NC 27695 ¤ bingli@uga.edu The most evolutionary advanced adaptations for plant parasitism by nematodes are the products of parasitism genes expressed in the pharyngealgland cells and secreted through the stylet into plant tissue. A direct method of microaspiration of cytoplasm from the pharyngeal gland cells of ten parasitic stages of Heterodera glycines from different time points in the parasitic cycle provided expressed mRNA to construct a gland cell-speci c cDNA library by long-distance-PCR. Of 2345 cDNA clones sequenced, deduced protein sequences of 231 cDNAs had a N-terminal signal peptide for secretion and, thus, could have roles in H. glycines parasitism of soybean. High- throughput in situ hybridisationwith probes of 112 cDNA clones encoding signal peptides resulted in 40 unique clones speci cally hybridising to transcripts within the subventral (11 clones) or dorsal (29 clones) gland cells. PSORT II predicted 30 of the proteins to be extracellular and ten proteins as nuclear localised. In BLASTp analyses, 25 of the predicted proteins were novel. Those proteins with similarities to known proteins included venom allergen like proteins, ß-1,4-endoglucanases, a pectate lyase, a chitinase, RanBPMs, and a cellulose- binding protein. Only two of the 40 gland-expressedgenes had homologues in Caenorhabditiselegans . 273 Activity of plant endoglucanase gene promoters in nematode feeding cells Melissa G OELLNER 1 ; ¤ , Xiaohong W ANG 2 , Ziv S HANI 3 , Oded S HOSEYOV 3 and Eric D AVIS 2 1 Developmental, Cell and Molecular Biology Group, Levine Science Research Center, Box 91000, Duke University, Durham, NC 27708, USA 2 Department of Plant Pathology, North Carolina State University, Raleigh, NC, USA 3 Kennedy-Leigh Center, Horticultural Research, The Hebrew University of Jerusalem, Rehovot, Israel ¤ mgoelln@duke.edu Five endoglucanase ( Ntcel ) genes were demonstrated to be upregulated in syncytia and giant-cells formed in Nicotiana tabacum by Globodera tabacum and Meloidogyne incognita , respectively. 1.5 kb of the 5 0 - anking genomic DNA region of the most strongly upregulated tobacco endoglucanase gene, Ntcel7 , was fused to the GUS reporter gene in a binary vector and used to produce hairy roots of tobacco and tomato, Lycopersicon esculentum , via Agrobacterium rhizogenes -mediated transformation. The 1.5 kb Ntcel7 promoter/GUS construct was expressed speci cally within plant root tips, lateral root initials, and appeared to be expressed within the feeding cells of root-knot and cyst nematodes in both tobacco and tomato hosts. These ndings agree with earlier evidence that an Arabidopsis 218 Nematology</p>
<p>Poster sessions thaliana endoglucanase ( Atcel1 ) promoter was active in the feeding cells of root-knot nematodes in transgenic tobacco. The apparent expression of the Ntcel7 promoter in feeding cells of cyst and root-knot nematodes in two plant species suggests that these promoters may have similar activity in other plant systems. 274 Identi cation and localisation of tomato expansin gene expression in nematode-induced syncytia B. G OLECKI 1 ; ¤ , S. F UDALI 2 , W. W IECZOREK 3 and F.M.W. G RUNDLER 3 1 Institut für Phytopathologie, Universität Kiel, 24098 Kiel, Germany 2 Department of Botany, Agricultural University, Warsaw, Poland 3 Institut für P anzenschutz, Universität für Bodenkultur, Vienna, Austria ¤ Bettina.Golecki@pfs.alr-kiel.landsh.de In the model system Arabidopsis thaliana/Heterodera schachtii ( Hs ) it was shown that speci c plant expansins are activated in nematode-induced syncytia. To prove whether the situation in the model system is transferable to susceptible crop plants, tomato roots were infected with Hs and Globodera rostochiensis ( Gr ), respectively. RT-PCR experiments with primers discriminating seven tomato ® -expansins showed that six expansins ( Le- Exp1, -3, -4, -5, -9 and -18) were expressed in or close to the syncytium, 10 and 14 days after inoculation. Le- Exp5 was further analysed by in situ RT-PCR. Ampli ed tomato expansin 5 cDNA could only be localised in the cytoplasm of syncytial cells but not in the surrounding root tissue. This indicates that tomato expansin 5 is speci cally expressed in syncytial cells and presumably plays an important role in the development of syncytia induced by cyst nematodes. 275 Arabidopsis thaliana expansin genes are expressed in syncytia induced by Heterodera schachtii B. G OLECKI 1 ; ¤ , K. W IECZOREK 2 , D.J. C OSGROVE 3 and F.M.W. G RUNDLER 2 1 Institut für Phytopathologie, Universität Kiel, 24098 Kiel, Germany 2 Institut für P anzenschutz, Universität für Bodenkultur, Vienna, Austria 3 Department of Biology, State University, Pennsylvania, USA ¤ Bettina.Golecki@pfs.alr-kiel.landsh.de The differentiation of syncytia of Heterodera schachtii ( Hs ) in roots of Arabidopsis thaliana is accompanied by cell wall loosening, extension and local degradation. In order to study whether speci c expansins are involved in this process, RT-PCR experiments with a syncytium- speci c cDNA library and primers differentiatingbetween 17 ® - and 3 ¯ -expansin cDNAs of Arabidopsis were per- formed. Speci c Arabidopsis mRNAs of 8 ® - and 1 ¯ - expansins were present in 5-7 day-old syncytia induced by Hs. In situ -RT-PCR experiments indicate that ampli- ed cDNA of At -Exp6 is localised in the cytoplasm of syncytial cells and not in the surrounding root. These re- sults could be con rmed with transgenic Arabidopsis pro- moter:gus lines. GUS activity was speci cally observed in syncytia and primordia of lateral roots. 276 Identi cation of gene expression differences between Globodera pallida and G. mexicana by suppressive subtractive hybridisation Eric G RENIER 1 ; ¤ , Vivian B LOK 2 , John J ONES 2 , Didier F OUVILLE 1 and Didier M UGNIÉRY 1 1 INRA UMR Biologie des Organismes et des Populations appliquée à la Protection des Plantes, Domaine de la Motte, B.P. 35657, 35653 Le Rheu cedex, France 2 Mycology, Bacteriology and Nematology Unit, SCRI, Invergowrie, Dundee DD2 5DA, UK ¤ grenier@rennes.inra.fr Globodera pallida and G. mexicana are two closely related species that are able to mate but usually develop on different solanaceous plants. Identi cation of nematode genes involved in parasitism is one of the most critical steps leading to the elucidation of disease resistance mechanisms in plants. In this study, we have used the Suppression Subtractive Hybridisation (SSH) technique to investigate differences between the transcriptomes of G. pallida and G. mexicana J2. None of the cDNA fragments isolated in the SSH experiments appeared to be completely absent from the other transcriptome, but differences in expression levels of some cDNAs between the two species were con rmed in reverse northern experiments. Sequence analysis revealed that a high proportion of the cloned sequences were pioneer genes for which no putative homologues were present in the databases. However, homologues of a cellulase and a putative pathogenicity factor previously described in G. rostochiensis were isolated. cDNAs corresponding Vol. 4(2), 2002 219</p>
<p>Parasitism (265-294) to these sequences were therefore compared between G. pallida and G. mexicana . 277 Identi cation of putative parasitism genes expressed in the pharyngeal gland cells of Meloidogyne incognita Guozhong H UANG 1 ; ¤ , Bingli G AO 1 , Tom M AIER 2 , Eric D AVIS 3 , Thomas B AUM 2 and Richard H USSEY 1 1 Department of Plant Pathology, University of Georgia, Athens, GA 30602, USA 2 Department of Plant Pathology, Iowa State University, Ames, IA 50011, USA 3 Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA ¤ ghuang@uga.edu Cloning parasitism genes coding proteins secreted from the pharyngeal gland cells and injected through the stylet into plant tissue is the key to understanding the molecular basis of nematode parasitism of plants. Microaspiration of the cytoplasm from the pharyngeal gland cells of 43 parasitic stages of M. incognita representing different time points in the parasitic cycle provided expressed mRNA to construct a gland cell-speci c cDNA library by long-distance-PCR. Of 1200 cDNA clones sequenced, deduced protein sequences of 141 cDNAs had an N- terminal signal peptide for secretion and, therefore, could have roles in root-knot nematode parasitism of plants. Of 101 cDNA clones encoding signal peptides tested by high-throughput in situ hybridisation, probes of 21 unique clones speci cally hybridised to transcripts within the subventral (seven clones) or dorsal (14 clones) gland cells. PSORT II predicted 18 of the deduced proteins to be extracellular and three as nuclear localised. In BLASTp analyses, 19 of the predicted proteins were novel proteins. Those with similarities to known proteins included a transcription factor and an avirulence protein. None of the 21 gland-expressed genes had homologues in Caenorhabditis elegans . 278 Expression of Arabidopsis thaliana gene PROLIFERA in nematode-induced feeding sites Xiang H UANG 1 ; ¤ , Patricia S PRINGER 2 and Isgouhi K ALOSHIAN 2 1 BASF Plant Science L.L.C., 26 Davis Drive, Research Triangle Park, NC 27709, USA 2 Department of Botany and Plant Sciences, and Department of Nematology, University of California, Riverside, CA 92521, USA ¤ huangx@basf-corp.com The initiation and formation of feeding sites in plant roots, induced by root-knot and cyst nematodes, involve the re- activation of cell cycle genes, resulting in multinucleated giant cells and syncytia. The feeding site serves as the nutrient source for the development and reproduction of the nematode. In order to extend our understanding of the interaction between nematodes and plants during the infection process, we have examined expression of the Arabidopsis PROLIFERA (PRL) gene during the development of nematode feeding sites (NFS). PRL is expressed in dividing cells throughout plant development and encodes an MCM protein thought to function in the initiation of DNA replication during S phase. We will present the expression pattern of PRL during formation of both giant cells and syncytia in the root of A. thaliana seedlings. 279 Direct identi cation of stylet secreted proteins from root-knot nematodes by a proteomic approach Stéphanie J AUBERT 1 ; ¤ , Terence Neil L EDGER 2 , Jean Baptiste L AFFAIRE 1 , Pierre A BAD 1 and Marie-Noëlle R OSSO 1 1 INRA, Unité Interactions Plantes-Microorganismeset Santé Végétale, 123 Bd F. Meilland BP2078, 60606 Antibes Cedex, France 2 Laboratoire de Pharmacologie Toxicologie INRA 180 ch. de Tournefeuille 31300 Toulouse, France ¤ jaubert@antibes.inra.fr The stylet secretions of sedentary plant-parasitic nema- todes are thought to be major pathogenicity factors in- volved in host invasion and feeding site induction and maintenance. A procedure was developed that allowed the direct qualitative analysis of proteins secreted by Me- loidogyne incognita infective juveniles. After stimulation in semi-sterile conditions, the secreted proteins whose pI ranged from 5.0 to 7.5 were separated by 2D electrophore- sis and the seven most abundant proteins were identi ed by micro-sequencing. A protein highly homologous to calreticulins was identi ed. The peptide sequences were used to design degenerate oligonucleotides that allowed the cloning of the corresponding Mi-crt cDNA. Transcrip- tion of Mi-crt in infective juveniles and adults was demon- strated. Expression of the calreticulin in the subventral pharyngeal glands of infective juveniles was evidenced, 220 Nematology</p>
<p>Poster sessions suggesting that calreticulin is a component of naturally produced stylet secretions and supporting the validity of the puri cation procedure. Calreticulin is a calcium bind- ing protein involved in multiple cellular functions. It is secreted by several animal-parasitic nematodes and trema- todes during parasitism. 280 Identi cation and expression analysis of pectin degrading enzymes from the root-knot nematode Meloidogyne incognita Stéphanie J AUBERT ¤ , Jean-Baptiste L AFFAIRE , Pierre A BAD and Marie-Noëlle R OSSO INRA, Unité Interactions Plantes-Microorganismeset Santé Végétale, 123 Bd F. Meilland BP2078, 60606 Antibes Cedex, France ¤ jaubert@antibes.inra.fr The establishment of sedentary parasitic root-knot nematodes in a host root is dependent on their ef ciency in invading the root tissue and in inducing the formation of a permanent feeding site. Several works have brought evidence that stylet secretions injected in the root tissue during parasitism are involved in those two phases of parasitism. Secreted enzymes involved in the invasion phase can be identi ed by a candidate gene approach. This strategy has previously allowed the identi cation of cellulolytic endoglucanases secreted by Meloidogyne incognita . In this study, pectin degrading enzymes were identi ed by analysing EST obtained from M. incognita infective juveniles. Two pectate lyase ( Mi-pel1 and Mi- pel2 ) and one polygalacturonase ( Mi-pg ) full length cDNAs were isolated. The deduced proteins contain a predicted secretion signal sequence. Transcription of the three genes was evidenced in pre-parasitic juveniles, sedentary females and males by RT-PCR. In infective juveniles the transcripts are localised in the subventral pharyngeal glands. Enzyme activities were analysed by in vitro tests. This study demonstrates that root-knot nematodes use a battery of cell wall degrading enzymes during parasitism. 281 Expression pattern of ENOD40 in tomato roots upon infection with root-knot ( Meloidogyne incognita ) and cyst ( Globodera rostochiensis ) nematodes Aneta K ARCZMAREK ¤ , Hein O VERMANS , Jaap B AKKER , Johannes H ELDER and Aska G OVERSE Laboratory of Nematology, Department of Plant Science, Wageningen University, Binnenhaven 5, 6709 PD Wageningen, The Netherlands ¤ Aneta.karczmarek@nema.dpw.wau.nl Early nodulin ( ENOD ) genes have been de ned as genes expressed in legumes during nodule formation. Recent studies, however, revealed a number of homologues of ENOD40 s in non-legume plants. Both in legumes and non-legumes ENOD40 s are thought to play a role in the development of vascular tissues. In situ localisation of ENOD40 transcripts in root-knot nematode-infected roots of the legume Medicago truncatula revealed that this plant gene is expressed in and around giant cells at 6 days post infection (dpi). To test the expression of ENOD40 in a non-legume upon infection with root-knot and cyst nematodes, the expression of endogenous ENOD40 promoter- gusA fusion was studied in nematode-infected tomato roots at 1, 3, 7 and 14 dpi. In the main root, GUS- stained areas were irregularly alternated with unstained areas. The lateral roots showed staining in the root-tip. Occasionally, GUS staining was observed in syncytia and giant cells. Sections from both GUS stained and non- stained feeding sites were investigated microscopically, and the results con rmed our macroscopic observations. Hence, ENOD40 expression in tomato is basically unaffected by the induction of feeding sites by root-knot and cyst nematodes. 282 Molecular cloning of chitinase genes from the pine wood nematode, Bursaphelenchus xylophilus Taisei K IKUCHI ¤ and Takuya A IKAWA Forestry and Forest Products Research Institute, Tsukuba Ibaraki 305-8687, Japan ¤ kikuchit@ffpri.affrc.go.jp Chitinase function in nematodes, other than during egg hatch, has been the subject of interest in recent years, particularly in animal-parasitic nematodes. In this study we describe the cloning of chitinase genes from the pine wood nematode, Bursaphelenchus xylophilus , which is mycetophagous and phytophagous, the causal agent of pine wilt and vectored between trees by insects. Degenerate primers derived from the conserved regions of known chitinase sequences were used to amplify fragments of putative B. xylophilus chitinase genes. Thus, two distinct fragments that encode chitinase sequences were obtained. Using these fragments as probes, corresponding cDNA clones were identi ed from Vol. 4(2), 2002 221</p>
<p>Parasitism (265-294) our mixed-stage cDNA library and designated as Bx -cht- 1 and Bx -cht-2. Sequence analysis revealed that Bx -cht-1 and Bx -cht-2 genes putatively encode proteins composed of 371 amino acids and 567 amino acids, respectively. The deduced amino acid sequences of these proteins showed signi cant homologies to chitinases of other nematodes. Our further analyses aim at identifying the timing and location of the chitinase genes expression in the nematode. 283 Novel pectate lyase gene from Globodera rostochiensis Urszula K UDLA ¤ , Ling Q IN and Geert S MANT Laboratory of Nematology, Department of Plant Science, Wageningen University, Binnenhaven 5, 6709 PD Wageningen, The Netherlands ¤ urszula.kudla@nema.dpw.wau.nl A novel cell wall degrading enzyme was identi ed as a part of cDNA-AFLP project that compared gene expression pro les in ve different stages of Globodera rostochiensis . One Transcript Derived Fragment (TDF), predominantly expressed in infective second stage juveniles, encoded a partial open reading frame showing high similarity to bacterial and fungal pectate lyases from the polysaccharide lyase 3 family (EC 4.2.2.2). The corresponding full-length cDNA designated Gr-Pel2 harbours an open reading frame of 759 bp, encoding polypeptide with molecular mass 27 kDa. Gr-Pel2 is signi cantly different from previously identi ed Gr- Pel1 (30% identities and 46% similarities). Sequence was predicted to have signal peptide for secretion at its N-terminal end. Digoxigenin-labelled DNA probe hybridised speci cally to the subventral pharyngeal glands, which are responsible for secreting all currently known cell wall degrading enzymes. Heterologous expression of Gr-Pel2 in Pichia pastoris is in progress, in order to assess its biochemical properties. Identi cation of another pectate lyase gene shows the complexity of the pectinolytic system in nematode secretions. 284 Analysis of root-knot nematode chorismate mutase expressed in soybean hairy roots Kris N. L AMBERT ¤ , E. D OYLE and J. P AINTER Department of Crop Sciences, University of Illinois, Urbana IL 61801, USA ¤ knlambert@uiuc.edu To gain insight into how plant pathogenic nematodes par- asitise plants, we have been isolating and characterising nematode genes that are expressed in the pharyngeal re- gion of the root-knot nematode, Meloidogyne javanica . One pharyngeal gland gene we had previously cloned was determined to be a chorismate mutase and was named MjCM-1 ( Meloidogyne javanica chorismate mutase). We determined this enzyme was secreted from the nematode as it was initiating its giant feeding cells. We hypothesised that MjCM-1 is manipulatingthe shikimate pathway in the plant to the bene t of the nematode. Since the shikimate pathway in plants produces metabolites that regulate plant development and plant defence, we hypothesised MjCM- 1 may be altering one of these processes. To test this hypothesis we have expressed MjCM-1 in soybean hairy roots using a dexamethasone inducible plant expression vector. Soybean hairy roots treated with dexamethasone express MjCM-1 and the roots exhibit a distinct lack of lateral roots. This result indicates that MjCM-1 can alter plant development. Metabolic pro ling experiments are being conducted on the MjCM-1 expressing roots to de- termine exactly which compounds are altered by this ne- matode enzyme. 285 Histochemical localisation of active oxygen species in Glycine max and Arabidopsis thaliana infected with the cyst nematodes Heterodera glycines and H. schachtii Kristen A. L ENNON ¤ and Thomas J. B AUM Department of Plant Pathology, 351 Bessey Hall, Iowa State University, Ames, IA 50011, USA ¤ kalen@iastate.edu The production of Active Oxygen Species (AOS) is considered to be an initial indicator and key component of the plant defence response. AOS have been implicated in direct pathogen inhibition through cell- wall modi cation, necrosis, direct pathogen mortality, signal transduction leading to defence-related gene expression, and programmed cell-death. The distribution and role(s) of AOS in plant-nematode interactions have yet to be well characterised. We used a histochemical approach to study the distribution of AOS in susceptible and resistant interactions between Glycines max and Heterodera glycines and in Arabidopsis thaliana infected with H. glycines or H. schachtii . In roots of G. max , AOS were associated with the head of the migrating nematode in the susceptible interaction but not in the resistant interaction. AOS were also not 222 Nematology</p>
<p>Poster sessions detected in either tissue once the nematode had initiated syncytium formation. In Arabidopsis roots, AOS were associated with nematode infection sites and possibly with developing syncytia. These observations were especially evident in the interaction between A. thaliana and H. schachtii . Arabidopsis roots infected with H. glycines exhibited similar staining patterns, but the incidence of nematode infection and feeding was lower. Patches of staining not directly associated with feeding nematodes were also observed. 286 Two novel Arabidopsis promoters with distinct tissue-speci cities are responsive to cyst nematode infection Mitra M AZAREI 1 ; ¤ , Kristen A. L ENNON 1 , Steven R. R ODERMEL 2 and Thomas J. B AUM 1 1 Department of Plant Pathology, 351 Bessey Hall, Iowa State University, Ames, IA 50011, USA 2 Department of Botany, Iowa State University, Bessey Hall, Ames, IA 50011, USA ¤ mmazarei@iastate.edu We previously isolated partial soybean cDNA clones whose corresponding transcript abundances are elevated 1 day after infection with the soybean cyst nematode, Heterodera glycines . Following, we isolated full-length cDNAs for two of these clones, designated Gm10.1 and Gm17.1 . RNA blot hybridisations revealed that Gm10.1 and Gm17.1 mRNAs accumulated in a root-preferential manner, and that their corresponding steady-state mRNA levels increased over time following H. glycines infection. The predicted Gm10.1 and Gm17.1 gene products each shared similarities with the protein products of distinct Arabidopsis thaliana genes with unknown functions. Promoters of these Arabidopsis genes, designated At10.1 and At17.1 , were fused to the GUS reporter gene and transformed into soybean hairy roots and Arabidopsis plants. Activity of the At10.1 promoter was detected in root and shoot apical meristems of Arabidopsis and in all tissues of soybean hairy roots. The At17.1 promoter also directed GUS expression to the root meristems but additionally was detected in the vascular tissues of both Arabidopsis and soybean. Furthermore, the At10.1 promoter was responsive to infection of Arabidopsis by Heterodera schachtii , whereas the At17.1 promoter directed increased GUS expression to the infection sites of H. glycines in soybean hairy roots. 287 Selection for virulence in populations of Globodera pallida Mark S. P HILLIPS ¤ , Roy N EILSON and Vivian C. B LOK Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK ¤ mphill@scri.sari.ac.uk Four populations of Globodera pallida were reared continuously on hosts with resistance derived either from Solanum vernei or S. tuberosum ssp. andigena CPC 2802. After 12 generations these populations were assessed biologically to determine if there was any increase in virulence. Bulk DNA derived from these populations was examined using AFLPs to assess the effects of selection on inter-population variation. Additionally, from a subset of the material, DNA was derived from individual second stage juveniles and was investigated using microsatellites to examine the effects of selection on inter- and intra- population variation. Biologically, selection resulted in increased virulence, but the increase varied depending on the initial population and the clone used. Increases in virulence tended to be speci c to the source of resistance. Molecular assessments showed an effect on the genetic constitution showing differences between the unselected and selected populations but showing no detectable association between polymorphic markers and virulence. The microsatellite data yielded allele frequencies that provided evidence that selection pressures had occurred in all four populations. Furthermore, a principal coordinate analysis derived from dissimilarity values based on microsatellite data separated the four populations into two host-speci c groupings that were different from the original G. pallida parent population. 288 Expression pro ling of the Arabidopsis -cyst nematode interaction David P. P UTHOFF 1 ; ¤ , Dan S. N ETTLETON 2 , Steven R. R ODERMEL 3 and Thomas J. B AUM 1 1 Department of Plant Pathology, 351 Bessey Hall, Iowa State University, Ames, IA 50011, USA 2 Department of Statistics, 124 Snedecor Hall 3 Department of Botany, 353 Bessey Hall, Iowa State University, Ames, IA 50011, USA ¤ dputhoff@iastate.edu Cyst nematodes infect and devastate many agricultural crops. After root penetration, cyst nematodes induce the formation of feeding cells (syncytia) within the host roots. Vol. 4(2), 2002 223</p>
<p>Parasitism (265-294) These syncytia are the sole source of nutrition for the ne- matodes. Syncytium formation is accompanied and likely mediated by nematode-inducedchanges in plant gene ex- pression. With the availability of microarray technology, mRNA expression changes of thousands of genes can be monitored simultaneously in order to determine the mechanisms of biological processes-of-interest. We have used Affymetrix GeneChip technology to monitor Ara- bidopsis mRNA changes following infection by two dif- ferent cyst nematode species. The sugar beet cyst nema- tode ( Heterodera schachtii ) readily infects Arabidopsis and induces syncytia. In contrast, the soybean cyst nema- tode ( H. glycines ) only rarely induces syncytium forma- tion in Arabidopsis roots while it retains the pre-feeding behaviours of probing and penetration. Our analyses un- covered a large panel of Arabidopsis genes with altered mRNA levels following cyst nematode attack. Some of these changes were observed during infection with both cyst nematode species, suggesting a potential involvement in plant stress or defence functions. Other mRNA changes were speci c for H. schachtii infection only and, there- fore, are good candidates for being involved in syncytium formation or function. 289 ESTScreen: identify secretory proteins in silico Ling Q IN 1 ; ¤ , Theo J.A. B ORM 2 and Jaap B AKKER 1 1 Laboratory of Nematology, Department of Plant Science, Wageningen University, Binnenhaven 5, 6709 PD Wageningen, The Netherlands 2 Laboratory of Plant Breeding, Department of Plant Science, Wageningen University, Binnenhaven 5, 6709 PD Wageningen, The Netherlands ¤ Ling.Qin@nema.dpw.wau.nl The ever increasing gene sequences in databases offer unprecedented opportunity for biologists to exploit this new information source to nd answers to various biological questions. The collection of a great number of EST (expressed sequence tags) is a useful starting place for identifying secretory proteins involved in nematode- plant interactions, either in the form of pathogenicity factors or avirulent proteins which are targeted by host defence mechanisms. SignalP is a robust program generally used to identify signal peptides for secretion from protein sequences, but it is not suitable for analysing a large number of EST directly. To this end, we have developed and validated a software tool, ESTScreen, which automates screening of thousands of EST either through the SignalP web server or a standalone version. ESTScreen searches each cDNA sequence for a (user-de ned) start codon, translates the sequence, submits automatically to SignalP and retrieves the output. ESTScreen then parses the SignalP prediction through a user-de ned logical test and generates a FASTA le containing only EST encoding a signal peptide for secretion, which can be used in homology search and other subsequent analysis. This program can be a useful tool in the study of plant-pathogen interaction systems as well as other elds in which secreted molecules play important roles. The authors wish to thank Dr. S. Kamoun for communicating unpublished results. 290 Identi cation of parasitism genes from root-knot nematode Meloidogyne incognita using cDNA-AFLP, EST-analysis and GenEST Erwin R OZE ¤ , Ling Q IN , Jaap B AKKER and Geert S MANT Laboratory for Nematology WUR, Binnenhaven 5, 6709 PD Wageningen, The Netherlands ¤ erwin.roze@nema.dpw.wau.nl The root-knot nematode Meloidogyne incognita is an obligatory plant parasite, which has evolved a complex feeding relationship with its host plants. Pharyngeal gland secretions play an important role in the parasitic life cycle of Meloidogyne spp. They are involved in migration through the root system and induction and maintenance of the giant cells. The cDNA-AFLP method is adopted to provide more insight in parasitism genes involved in the plant-nematode interaction. Gene expression pro les of various M. incognita stages differing in pharyngeal gland activity ( e.g. , eggs, pre-parasitic and parasitic juveniles, adult females) are being compared in a cDNA- AFLP procedure based on the restriction enzymes Apo I and Taq I. Genes speci cally expressed in the parasitic stages may represent candidate parasitism genes and will be isolated from gel. The DNA sequences of the isolated fragments will be compared with the M. incognita EST database using the computer program GenEST. Furthermore, the spatial expression pattern of the candidates will be analysed using whole mount in situ hybridisation. 291 Localisation of expression of Le -Exp5 gene in feeding sites induced by Globodera rostochiensis in roots of susceptible tomato using in situ RT-PCR method 224 Nematology</p>
<p>Poster sessions M. S OBCZAK 1 ; ¤ , S. F UDALI 1 , B. G OLECKI 2 , S. J ANAKOWSKI 1 , G. G RYMASZEWSKA 1 , W. K UREK 1 , M. L ICHOCKA 1 , F. G RUNDLER 3 and W. G OLINOWSKI 1 1 Department of Botany, Warsaw Agricultural University, Rakowiecka 26/30, Warsaw 02528, Poland 2 Institute of Phytopathology, Christian-Albrechts University, Kiel, Germany 3 Department of Plant Protection, University of Agricultural Sciences, Vienna, Austria ¤ Sobczak@delta.sggw.waw.pl The expression pattern of the tomato expansin gene Le - Exp5 was examined on resin and agar embedded sections of syncytia induced by Ro1 pathotype of G. rostochiensis in roots of susceptible tomato cv. Moneymaker. In 1 and 3 day old syncytia, strong expression of Le -Exp5 was found in cells incorporated into syncytium and in neighbouring cells. In 7 day old syncytia, the older parts of syncytia contained relatively less Le -Exp5 mRNA than cells situated at distal parts of syncytia that had been recently incorporated into it. Strong expression of Le -Exp5 took place also in proliferating and dividing parenchymatous cells surrounding syncytia. These results were gained in experiments where in situ RT-PCR was followed by in situ hybridisationwhich con rmed the RT- PCR data. 292 Micropreparative sampling and molecular characterisation of proteins secreted by the plant-parasitic nematode Heterodera schachtii B. V ANHOL ME 1 ; ¤ , J. D E M EUTTER 2 , T. T YTGAT 3 , G.D.C. G HEYSEN 1 , I. V ANHOUT TE 2 and G.D.R. G HEYSEN 1 1 Vakgroep Moleculaire Biotechnologie, Faculteit Landbouwkundige en Toegepaste Biologische Wetenschappen, Universiteit Gent, Coupure links 653, B-9000 Gent, Belgium 2 VIB, Departement Plantengenetica, Faculteit Wetenschappen, Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium 3 Instituut voor Dierkunde, Faculteit Wetenschappen, Universiteit Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium ¤ bahol@gengenp.rug.ac.be Sedentary plant-parasitic nematodes such as Heterodera schachtii have evolved a highly complex relationship with their host plant by redifferentiating root cells into specialised feeding sites. Proteins, produced in the pharyngeal glands of the nematode and injected into the plant cell, are thought to play a key role in this sophisticated transformation. The key to understand this form of parasitism is the characterisation of these proteins. However, the small size of plant-parasitic nematodes makes direct analysis of their secretions extremely dif cult. We present a method to isolate nematode secretions in suf cient quantities to allow direct analysis by combining two-dimensional gel electrophoresis and mass-spectrometry. So far, we have been able to identify several proteins (endoglucanasesand pectate lyase) which are believed to be involved in the invasion of the plant tissue by the nematode. Other spots from the two- dimensional gels are under investigation.This knowledge will help us to elucidate one of the most fascinating forms of parasitic behaviour between two completely different organisms, namely a plant and an animal. 293 Cloning genes expressed in the pharyngeal gland cells of Heterodera glycines using an ampli ed RNA technique Xiaohong W ANG 1 ; ¤ , Tom M AIER 2 , Richard H USSEY 3 , Thomas B AUM 2 and Eric D AVIS 1 1 Department of Plant Pathology, Campus Box 7616, North Carolina State University, Raleigh, NC, 27695, USA 2 Department of Plant Pathology, Iowa State University, Ames, IA, USA 3 Department of Plant Pathology, University of Georgia, Athens, GA, USA ¤ iaohong_wang@ncsu.edu mRNA within the cytoplasm microaspirated from the pharyngeal gland cells of parasitic stages of Heterodera glycines was immobilised on paramagnetic beads for initial cDNA synthesis. T3 and T7 promoters were adapted to the gland cell cDNA and used to drive several rounds of in vitro transcription. The ampli ed RNA pool was used for cDNA synthesis and directional cloning into a plasmid vector for construction of a H. glycines gland-cell cDNA library without using PCR. Analysis of 90 cDNA clones chosen at random from the library produced 67 unique cDNA sequences. Among the 67 H. glycines cDNA sequences were homologues to a number of different eukaryoticgenes, includinggenes identi ed in animal-parasitic nematodes and genes with potential roles in host-parasite interactions. The presence of a predicted secretion signal peptide and con rmation of expression in H. glycines pharyngeal gland cells are being investigated for these and additional clones being sequenced from the ampli ed RNA H. glycines gland-cell cDNA library. Vol. 4(2), 2002 225</p>
<p>Parasitism (265-294) 294 SSH enriched cDNA libraries to compare virulent and avirulent isolates of the quarantined root-knot nematode Meloidogyne chitwoodi Jane W ISHART ¤ , Alison P ATERSON , Mark S. P HILLIPS and Vivian C. B LOK Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, UK ¤ Jwisha@scri.sari.ac.uk In north-western Europe, root-knot nematodes are a se- rious threat for potato production particularly with re- duced use of nematicides. Meloidogyne chitwoodi causes signi cant economic losses due to reduction in tu- ber quality and yield of potato crops. Resistance to M. chitwoodi has been identi ed in the wild tuber- bearing Solanum species, S. bulbocastanum. Three patho- types were identi ed suggesting at least two differ- ent genetic factors for virulence and resistance in the pathogen and the host species respectively. This has important implications for the successful utilisation of resistance from S. bulbocastanum . Roots of S. bulbocastanum were infested with two isolates of M. chitwoodi varying in virulence. Plants were propagated in tissue culture and then transferred to soil before inoculating. The infection process was monitored by histological examination of roots allowing time points to be selected for RNA extraction. cDNA libraries were constructed from infected root tissue using the Suppressive Subtractive Hybridisation (SSH) method which enriches for rare transcripts. This enabled the construction of libraries, enriched in transcripts from the compatible and incompatible interactions, at 3 and 7 days post-infection. Both plant and nematode genes, which may be important during the host/parasite interaction, were identi ed. 226 Nematology</p>
<p>Poster sessions 295 Resistance to Meloidogyne incognita in coffee: identi cation of molecular markers F-AFLP in resistant genotypes Ana Paula de Andrade A UKAR ¤ and Eliana Gertrude Macedo L EMOS UNESP, Campus de Jaboticabal, Departamento de Tecnologia, Via de acesso Prof. Paulo Donato Castelani KM 5, Jaboticabal, SP14870-000, Brazil ¤ aukar@fcav.unes.br This study is about a diagnostic system based on molecular markers that co-segregate within a gene of interest. The chosen techniquewas f-AFLP due to its great power of detection of genetic variability,being a dominant marker ef cient for large and simultaneous sampling of a genome. A total of 16 primers combination ECO-RI ( C 3) and MSE-I ( C 3) were used to study polymorphism within a population of 40 plants F5 (H 47-82-7-925), donated by Instituto Agronomico de Campinas – IAC, segregating for the resistance to Meloidogyne incognita nematode in coffee tree. One hundred and twenty eight segregating loci were obtained with Mendelian inheritance by selecting only markers that segregated 1:1. These markers were submitted to a comparative analyses between the donor of the resistance factor of this progeny ( Coffea canephora duplicated – C1330) and the plant group that is resistant and susceptible (‘bulk’ resistant and ‘bulk’ susceptible). 296 Nematode control by expression of lectins in transgenic plants Katrien C ARLENS 1 ; ¤ , Annemie E LSEN 1 , Els V AN D AMME 2 , Laszlo S AGI 1 , Dirk D E W AELE 1 and Rony S WENNEN 1 1 Laboratory of Tropical Crop Improvement, Kasteelpark Arenberg 13, B-3001 Leuven, Belgium 2 Laboratory for Phytopathology and Plant Protection, Willem De Croylaan 42, B-3001 Leuven, Belgium ¤ katrien.carlens@agr.kuleuven.ac.be With the advent of transgenic methodologies,an attractive method to control plant parasitic nematodes is the transfer into plant host species of genes encoding nematicidal proteins. Lectins or lectin-related proteins, for example, are believed to have toxic and/or repellent effects on nematodes. As a good host for migratory and sedentary nematodes and being considerably easier to transform than most plants, Arabidopsis thaliana can be used as an in vitro system to rapidly express transgenes and evaluate their putative nematicidal effect. Three tropical nematode species ( Radopholus similis , Pratylenchus coffeae and Meloidogyne incognita ) could successfully penetrate and develop in A. thaliana under monoxenic conditions. Eight to 10 weeks after inoculation reproduction ratios of respectively 16.3, 11.9 and 24 could be observed. This in vitro system enables the preselection of genes or gene combinationsshowing the greatest potential for nematode control. Transgenic Arabidopsis plants, expressing lectins or lectin-related proteins in their roots, have already been screened. Results on nematode penetration and multiplicationin these transgenic plants will be presented. 297 Marker-assisted selection in screening peanut ( Arachis hypogaea L.) for resistance to the peanut root-knot nematode Valeria C ARPENTIERI -P IPOLO 1 , Don W. D ICKSON 2 ; ¤ , Maria G ALLO -M EAGHER 3 and Dan W. G ORBET 4 1 Universidade Estadual de Londrina, Depto Agronomia, C.P. 6001, 86051-990, Londrina PR, Brazil 2 University of Florida, P.O. Box 110620, Gainesville, FL 32611, USA 3 University of Florida, P.O. Box 11030, Gainesville, FL 32611, USA 4 University of Florida, REC, Hwy 71, Marianna, FL 32446, USA ¤ dwd@.u .edu A restriction fragment length polymorphism (RFLP) marker linked to a locus for resistance to Meloidogyne arenaria race 1, along with visual evaluation following root staining were used to screen four breeding populations and three lines of peanut in a root-knot nematode infested eld. Coan and Florunner cultivars were used as the resistant and susceptible parental controls, respectively. Genomic DNA was isolated from young leaves of these plants during the growing season, and Southern blot analysis was conducted using the RFLP probe R2430E. Only line T301-1-8 was homozygous for the resistance marker. At harvest, root systems were stained with Phloxine B, egg masses counted, and resistance phenotype scored. Field tests con rmed the RFLP marker results. Except for T301-1-8, all other genotypes displayed high levels of nematode reproduction. The RFLP probe R2430E loci linked to nematode resistance provided a useful selection method for identifying resistance to the peanut root-knot nematode. Vol. 4(2), 2002 227</p>
<p>Resistance, breeding (295-335) 298 Understanding the genetic and molecular basis of (a)virulence in the root-knot nematode Meloidogyne incognita Philippe C ASTAGNONE -S ERENO INRA Unité IPMSV, BP2078, 06606 Antibes cédex, France pca@antibes.inra.fr Using two pairs of near-isogenic M. incognita lines, avirulent and virulent against the tomato Mi resistance gene, a cDNA-AFLP differential analysis was initiated, in order to identify genes differentially expressed between avirulent and virulent nematodes. AFLP markers were developed on cDNA templates digested with Hind III and Mse I, with all of the 256 combinations that could be generated with primers with two selective nucleotides. A total of approximately 84 000 fragments were ampli ed, among which 61 appeared differential ( i.e. , present in the two avirulent lines and absent in the two virulent lines). In order to con rm this result, cDNA-AFLP was run again on the same templates, but with all of the 64 combinations that could be generated with primers with two selective nucleotides for Mse I and one selective nucleotide for Hind III. This allowed us to eliminate a number of false positive bands, and 19 fragments differential between avirulent and virulent lines were thus selected for further analysis. The next experimental steps included cloning of the full-length genes, RT-PCR experiments, etc. The results will be discussed in relation to the ability of the nematode to overcome or not the plant resistance gene. 299 Characterising sources of resistance to Globodera pallida and G. rostochiensis identi ed in the Commonwealth potato collection Lydia C ASTELLI ¤ , Glenn B RYAN , Gavin R AMSAY , Robbie W AUGH and Mark P HILLIPS Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK ¤ lcaste@scri.sari.ac.uk Previously untested material from Professor JG Hawkes’ collection of wild species of potatoes now incorporated into the CPC was screened against the potato cyst nema- todes. A total of 56 and 53% of accessions were identi- ed as having resistance to G. pallida and G. rostochien- sis, respectively, from 198 accessions. Molecular analy- sis of the resistant accessions identi ed was conducted to observe the genetic relatedness and diversity of the ma- terial, using the AFLP DNA ngerprinting technique. A total of four primer combinations were applied, yield- ing 275 identi able marker bands. Analysis of the iden- ti ed marker bands was then completed using a hierar- chical cluster analysis and a dendrogram produced. The dendrogram was then used to identify 16 genetically di- verse species for further analysis. These species have been tested against a range of G. pallida populations.Histolog- ical analysis of the resistance mechanisms involved has also been conducted, focusing on the effect of the wild species on hatch, invasion, development in the root and production of eggs per cyst. 300 Host-plant response of some Musa cultivars from Brazil to different species of root-knot nematodes ( Meloidogyne spp.) E. C OFCEWICZ 1 , R.M. C ARNEIRO 2 , P. Q UÉNÉHERVÉ 3 and J.L. F ARIA 1 1 University Federal de Pelotas, C.P. 354, CEP 96001-970, Pelotas, RS, Brazil 2 EMBRAPA, CP 08223, CEP 70849-970, Brasilia, DF, Brazil 3 IRD, BP 8006, 97259 Fort-de-France cedex, Martinique Five Musa cultivars commonly grown in Brazil, (triploid AAA-group, cvs Nanicão and Caipira; triploid AAB- group, cvs Prata and Terra; tetraploid AAAB-group, cv. Pioneira) were evaluated for their susceptibility to three different root-knot species ( Meloidogyne javanica , M. in- cognita , M. arenaria ) alone and in combinations under glasshouse conditions. Four months after nematode in- oculation, plant growth parameters ( e.g ., fresh and dry weights, number of leaves and foliar area, macro- and micro-element concentrations), nal nematode popula- tions, reproductive factor and interspeci c competition were analysed. All Musa cultivars were found to be hosts for the three Meloidogyne species. The highest nema- tode multiplicationwas observed with M. incognita on cv. Prata. The cv. Caipira seemed the most susceptible to Me- loidogyne infestation in terms of plant growth parameters when inoculated with a mixture of M. javanica and M. in- cognita . The calcium content of Musa cultivars is the only macroelement which increased systematically when in- fested with root-knot nematodes ( e.g ., signi cant increase with cvs Prata, Caipira and Terra). Based on their multi- plication rates and on the Musa cultivar, some competition between root-knot nematode species was observed. 301 Evaluation of beans and cowpea genotypes for resistance to Meloidogyne javanica 228 Nematology</p>
<p>Poster sessions Aline G ODOY C RAVEIRO 1 , João F LÁVIO V ELOSO S ILVA 1 ; ¤ , Geraldo E. Souza C ARNEIRO 1 , Maria José D EL P ELOSO 2 and Francisco Rodrigues F REIRE F ILHO 3 1 Embrapa Soja 2 Embrapa Arroz & Feijão 3 Embrapa Meio Norte, CP 231, 86001-970, Londrina, PR, Brazil ¤ veloso@cnpso.embrapa.br Meloidogyne javanica is a major nematode pathogen in soybean in Brazil. In many regions beans and cowpeas are used in rotation with soybeans, increasing the problem. The use of nematode resistant cultivars in rotations with soybean can help reduce the damage. The reproduction of Meloidogyne javanica was studied on 21 bean and seven cowpea genotypes.The plants were grown on plastic tubes in glasshouse conditions, inoculated with 3000 nematode eggs and evaluated for egg production after 42 days. Tomato plants were used as inoculum ef ciency check. The same genotypeswere grown in a M. javanica -infested eld and were evaluated for galling index. Despite high tolerance in eld conditions, all cowpea genotypes permitted abundant nematode reproduction. The bean genotypes Aporé and Pot-51 were resistant whereas the majority was susceptible. 302 Resistance to Heterodera ciceri , Meloidogyne artiellia and Pratylenchus thornei in wild species of chickpea M. D I V ITO 1 , N. G RECO 1 and R.S. M ALHOTRA 2 1 Istituto per la Protezione delle Piante, Sezione di Bari, C.N.R., Via Amendola, 165/A 70126 Bari, Italy 2 International Center for Agricultural Research in Dry Areas, Aleppo, Syria nemamd03@area.ba.cnr.it Chickpea ( Cicer arietinum ) is an important food legume throughout the world. Heterodera ciceri , Meloidogyne artiellia and Pratylenchus thornei are nematodes known to affect the crop. Chickpea germplasm evaluation has revealed the absence of resistance to these nematodes. Therefore, different lines belonging to eight wild Cicer species were screened for their reaction to a Syrian populations of H. ciceri and P. thornei , and to an Italian population of M. artiellia in a glasshouse. Out of 207, 154 and 249 lines of Cicer spp. tested for their reaction against H. ciceri , M. artiellia and P. thornei , respectively, 17 of C. bijugum , six of C. pinnatidum , and ve of C. reticulatum were resistant to H. ciceri . One line each of C. bijugum , C. chorassanicum and C. judaicum , and two each of C. pinnatidum and C. reticulatum were resistant to M. artiellia . Six lines of C. bijugum , four of C. cuneatum , 16 of C. judaicum and one of C. yamashitae were resistant to P. thornei . Because C. reticulatum is crossable with C. arietinum , these ndings indicate the possibility of introgression of resistance to H. ciceri and M. artiellia into the cultigen. 303 Characterisation and high-resolution genetic mapping of root-knot nematode resistance genes in pepper ( Capsicum annuum L.): comparison with the tomato and potato nematode resistance gene locations C. D JIAN -C APORALINO 1 ; ¤ , V. L EFEBVRE 2 , A. P ALLOIX 2 and P. A BAD 1 1 INRA, Unité Interactions Plantes Microorganismes et Santé Végétale, 123 bd Francis Meilland, 06606 Antibes cedex, France 2 INRA, Unité de Génétique et Amélioration des Fruits et Légumes, Domaine Saint Maurice, 84143 Montfavet cedex, France ¤ caporali@antibes.inra.fr In pepper, researches on genetic basis of root-knot nematode resistance were conducted on three genetically distant accessions: PM687, PM217 and CM334. They revealed three dominantand thermostable loci with broad- spectrum of resistance: Me3, Me1 and Me7 , and two other loci: Mech1 (PM217) and Mech2 (CM334) controlling the quarantine nematode M. chitwoodi . Comparative histological studies showed that the three broad-spectrum resistance genes suppressed nematode reproduction, but induced very different response patterns in root cells upon nematode infection. Bulked-segregant analysis was performed to identify AFLP markers linked to the genes. Fine mapping of Me3 gave AFLP less than 0.5 cM anking the gene. Indirect selection markers (SCAR or CAPS) were identi ed. Me 3 locus was localised on chromosome P9 on intraspeci c pepper maps, in a syntenic region of two other nematode resistance genes, the tomato Mi-3 and the potato Gpa 2 genes, which mapped on the short arm of the tomato and potato chromosome 12. We also identi ed new AFLP markers linked in coupling to M. chitwoodi resistance genes. The nearest were located less than 1.7 cM from Mech1 (no recombinant individual for two markers), and at 1 cM from Mech2 (one recombinant individualfor one marker). Vol. 4(2), 2002 229</p>
<p>Resistance, breeding (295-335) 304 Comparison of two screening methods for early evaluation of resistance to Radopholus similis in Musa germplasm Carine D OCHEZ 1 , Danny C OYNE 2 , Michael P ILLAY 1 and Dirk D E W AELE 3 1 International Institute of Tropical Agriculture (IITA) – Eastern and Southern Africa Regional Centre (ESARC), P.O. Box 7878, Kampala, Uganda 2 IITA – Ibadan, Nigeria, c/o Lambourn & Co., Carolyn House, 26 Dingwall Road, Croydon, CR9 3EE, UK 3 Katholieke Universiteit Leuven, Laboratory of Tropical Crop Improvement, Kasteelpark Arenberg 13, 3001 Leuven, Belgium Plant-parasitic nematodes are one of the most important constraints to sustainable Musa production. In the lowlands of Central Uganda, the most common nematode species is Radopholus similis , while at higher elevations Pratylenchus goodeyi is more prevalent. The use of host plant resistance provides promising prospects towards sustainable nematode management through conventional breeding. To identify resistance, reliable screening methods need to be developed. In this study two screening methods for resistance to nematodes are compared. The rst screening method is based on the inoculation of individual roots placed in a cup. The second screening method is based on the classic pot experiment, whereby the complete root system is inoculated. The newly developed cup method requires less nematode inoculum and less plant material per cultivar compared to the pot experiment. By using single roots for inoculation, the host response to nematode attack is not in uenced by differences in root growth rates between Musa genotypes. Hybrids developed within the banana breeding programme of the International Institute of Tropical Agriculture are being evaluated for resistance against Radopholussimilis using both methods. Nematode reproductionratio is compared against a known resistant check (Yangambi km 5) and a known susceptible check (Valery). The results of both screening methods will be discussed. 305 Proteomic analysis of soybean cyst nematode (SCN) inoculated soybean roots J. F AGHIHI 1 ; ¤ , R.A. V IERLING 2 and V.R. F ERRIS 3 1 Department of Entomology 2 Department of Agronomy 3 Department of Entomology, Purdue University, West Lafayette, IN 47907, USA ¤ Jamal@entm.purdue.edu Proteins and small molecules within a soybean root at any given time depend on genes expressed up to that time and are in uenced by the genotype and the environment. Earlier, we demonstrated reproducibility of an extraction and chromatographic protocol used to compare pro les from roots exposed to either biotic or abiotic stresses. We have challenged cvs Williams 82 and Hartwig, and our SCN resistant germplasm PUSCN14 with Heterodera glycines and analysed the ngerprints at different time intervals following inoculation. Gross comparison of the chromatographs showed considerable similarity between the inoculated and non-inoculated samples of the same cultivar. However, analyses of peak areas (four replications) showed statistically signi cant ( P D 0 : 05 / alterations of speci c peak areas due to stress. All three cultivars showed a transient increase in the peak 11 area 2 days after inoculation but returned to non- stressed levels at 4 days after inoculation. Interestingly, peak 5 showed an increase in levels 4 days after inoculation. Selected peaks were collected and analysed by mass spectrometry. 306 Chitin synthase as molecular target in the plant-parasitic nematode Meloidogyne artiellia Elena F ANELLI 1 ; ¤ , Mauro D I V ITO 2 , Maria Rosaria C ORTESE 1 and Carla D E G IORGI 1 1 Università degli Studi di Bari, via Orabona n ± 4, 70126 Bari, Italy 2 Istituto di Protezione delle Piante CNR, via Amendola 165/A, 70126 Bari, Italy ¤ e.fanelli@biologia.uniba.it Plant-parasitic nematodes cause serious damage to agricultural crops. Molecular biology studies are focusing on plant-parasite interactions with the aim of nding the weak point that will permit nematode control. In spite of this, several chemical compounds are still used as nematicides that are speci c inhibitors of the synthesis of chitin which is present in the eggs of nematodes. Data in the literature indicate successful applications of chemical compounds suggesting that these may affect nematode- egg formation by interfering with chitin deposition in the nematode egg-shell. The prevention of chitin synthesis may be triggered by an inhibition of the proteolitic activation of chitin synthase zymogen or can be due to a direct effect on the chitin synthase. In this presentation, we show that the eggs of M. artiellia do contain chitin and 230 Nematology</p>
<p>Poster sessions have chitin synthetic activity. In our laboratory we have isolated in the eggs of M. artiellia two different portions of chitin synthase cDNA by RT-PCR. One of the cDNA contains the motif QRRRW, which is demonstrated to be conserved in chitin synthase of different organisms. To prove that the encoded protein shows chitin synthase activity, we will express both clones and their enzymatic activity will be tested. 307 Evaluation of soybean genotypes for host suitability to Meloidogyne incognita race 2: an in vivo study Hendrika F OURIE 1 ; ¤ , Alexander Henrique M C D ONALD 1 , Dirk DE W AELE 2 and Alwyn Jacobus DE L ANGE 1 ARC-Grain Crops Institute, Private Bag X1251, Potchefstroom, 2520, South Africa 2 Lab. Tropical Crop Improvement, K.U. Leuven, Kasteelpark Azenburg 13, 3001, Heverlee, Belgium ¤ driekie@igg2.aric.za M. incognita race 2 is predominant on soybean in South Africa. Sixty-nine soybean hybrids were evaluated for host suitability to this species in the glasshouse. Each seedling was inoculated with 10 000 eggs and larvae. Assessments were made 56 days after inoculationand RF- values were calculated. Five soybean genotypes S5995, Potties, PAN660, TXS89/10/29 and D82-3298, identi ed as poor hosts in glasshouse screenings, were evaluated under natural conditions in microplots and in the eld to verify their resistance. Prima 2000 was included in both trials as a susceptible standard. In the microplot trial each seed was inoculated with 10 000 eggs and larvae at planting while a uniform and natural distribution of M. incognita race 2 occurred in the eld trial. Meloidogyne incognita race 2 eggs and larvae were extracted and counted 90 days after planting. S5995 maintained the lowest numbers of M. incognita race 2 in the above- mentioned trials, followed by PAN660, TXS89/10/29, D82-3298 and Potties, and differed signi cantly from the susceptible control (Prima 2000). Crosses between these poor-host cultivars and Prima 2000 are underway to develop a mapping population for identi cation of genetic markers associated with this resistance trait. 308 SSR markers associated with resistance to Meloidogyne javanica in soybean Renata F UGANTI , João Flávio V ELOSO S ILVA ¤ , Carlos A. Arrabal A RIAS and Silvana R. M ARIN Embrapa Soja, CP231, 86001-970, Londrina, PR, Brazil ¤ veloso@cnpso.embrapa.br Meloidogyne javanica is a major nematode pathogen in soybean in Brazil. The development of resistant varieties is the main goal of many breeding programmes. Progress in selection for nematode resistant lines can be speeded up by the use of molecular markers associated with genes for resistance. The objectives of this study were to use SSR markers to identify quantitative trait loci (QTL) conditioning soybean resistance against M. javanica and to determine their genomic location. Eighty-eight SSR markers were used to amplify the DNA of soybean lines (25 resistant and 26 susceptible) obtained from a cross between BRS 133 (susceptible) and PI 595099 (resistant), and selected in previous studies by galling number assayed in glasshouse and infested eld. HSP 176, Satt 114 and Satt 423 showed signi cant association with resistance. The QTL analysis on the linkage group indicated the presence of at least one gene on HSP 176 locus (Lod 27.5). In all gene extensions between Satt 114 and HSP 176 (8.3 cM), the Lods were high (22.6-27.5). 309 Ultrastructure of resistant responses of selected Solanum bulbocastanum lines to infection with Meloidogyne chitwoodi W. G OLINOWSKI 1 ; ¤ , J. J UPOWICZ 1 , M. S OBCZAK 1 , G. G RYMASZEWSKA 1 , W. K UREK 1 , F. Z OON 2 , and H. VAN DER B EEK 2 1 Department of Botany, Warsaw Agricultural University, Rakowiecka 26/30, Warsaw 02528, Poland 2 Plant Research International, Wageningen, The Netherlands ¤ Golinowski@delta.sggw.waw.pl Different genotypes of S. bulbocastanum varying in resistance to different isolates of M. chitwoodi were examined by electron microscopy. In moderately resistant combinations feeding sites were composed of two to three strongly enlarged giant cells derived from procambium. They contained condensed cytoplasm, small cytoplasmic vacuoles, enlarged nucleus with dispersed heterochromatin, electron translucent nucleoplasm and hypertrophied nucleolus. In resistant combinations two different plant responses were found. If giant cells were induced among procambial cells their cytoplasm was strongly condensed. The central vacuole was substituted by small cytoplasmic vacuoles. The nucleus was enlarged and amoeboid and the nucleolus contained many Vol. 4(2), 2002 231</p>
<p>Resistance, breeding (295-335) nucleolar ‘vacuoles’. If giant cells were induced among cortical or pericyclic cells they contained only paramural layer of strongly osmiophilic cytoplasm. The central vacuole was present and lled with brillar material. Neighbouring cells contained large starch grains. Many surrounding cells necrotised or divided hyperplastically. In absolutely resistant combinations juveniles induced slight enlargement of selected vascular cylinder cells. Their cytoplasm was located paramurally. Their central vacuoles were lled with osmiophilic granules. Later on, giant cells degenerated and the juveniles were embedded in a layer of degraded cells. Some cortical cells were enlarged and contained many large starch grains. 310 Effective and durable resistance against plant-parasitic nematodes Sarah G OODCHILD ¤ , Peter U RWIN and Howard A TKINSON Department of Biology, University of Leeds, Leeds, LS2 9JT, UK ¤ bgysag@leeds.ac.uk The success of transgenic approaches to plant-parasitic nematode resistance will require an effective and durable defence. This work aims to de ne new targets that can be disrupted with a deleterious consequence on the animal. Two candidate genes have been selected as putative targets. The rst is a gene encoding an aspartic proteinase isolated from an H. glycines library using a PCR fragment produced by degenerate primers. The second is an aminopeptidase, also isolated from an Heterodera glycines cDNA library by heterologous probing with C. elegans EST. Recombinant proteins correspondingto both genes have been expressed in order to conduct inhibitor assays. Plant derived aspartic proteinase inhibitors have been shown to be effective in vitro and have subsequently been transformed into Arabidopsis thaliana under the control of CaMV35s promoter. Infecting the transformed plants with H. schachtii will assess the potential of these inhibitors as a defence strategy. There are no inhibitors of aminopeptidases described from a plant source, therefore synthetic peptide and antibody phage display libraries are being screened to isolate a functional inhibitor. In situ hybridisation experiments indicate that the aspartic proteinase gene is expressed intestinally whereas the aminopeptidase gene is expressed in the reproductive system. 311 Tolerance of sugar beet to Heterodera schachtii Johannes H ALLMANN 1 , Katherine G IERTH 2 , Josef S CHLANG 1 , Joachim M ÜLLER 1 and Richard A. S IKORA 2 1 Federal Biological Research Center for Agriculture and Forestry, Toppheideweg 88, D-48161 Münster, Germany 2 Institute of Plant Diseases, Nussallee 9, D-53115 Bonn, Germany The crop potential to produce high yields even under severe nematode pressure is an important economic trait in integrated control strategies. Plant tolerance is especially important for beet and tuber crops where nematode damage at the early stages can delay or destroy beet/tuber formation. Breeding of tolerant cultivars is currently limited by our poor understanding regarding functioning and inheritance of tolerance. In eld studies and glasshouse experiments, a broad spectrum of sugar beet cultivars/hybrids was studied for tolerance of Heterodera schachtii . Three cultivars/hybrids were selected for further studies on the mechanisms of tolerance: Nematop (tolerant/resistant), Stru.1915 (tolerant, susceptible) and Penta (intolerant/susceptible). With increasing nematode pressure, yield decrease in the tolerant cv. Nematop and tolerant hybrid Stru.1915 was signi cantly less than in the intolerant cv. Penta. Tolerant plants suffered later from water stress and the rate of photosynthesis was generally higher. Furthermore, tolerant plants showed higher compensatory growth, and increased rooting depth. Tolerance was most pronounced under dry summer conditions and less obvious under humid conditions. The concept of using plant tolerance for managing plant parasitic nematodes will be discussed. 312 Growing resistant sugar beets; a new opportunity in elds infected with Heterodera schachtii D. H EINICKE P anzenschutzamt Postfach 910810, D 30428 Hannover, Germany Heinicke@Lawikhan.de In sugar beet rotations, Heterodera schachtii is now kept below the economic threshold by growing resistant varieties. Resistant oil radish, or mustard, grown in autumn is not as effective as in spring. The density dependent reduction after oil radish is 0.36 Pf/Pi compared with 0.64 Pf/Pi after fallow. Even though the reduction is quite effective, the high multiplication rate of H. schachtii on sugar beet overcomes the effect on the 232 Nematology</p>
<p>Poster sessions Pi . These problems are now overcome by resistant and tolerant sugar beet varieties. With a Pi between 10 and 30 eggs C juveniles/g soil, the Pf/Pi lies between 0.9 and 0.7 while the yield is 5-20% higher with a tolerant variety than compared to a susceptible one in an infested eld. On the other hand, resistant varieties earn 10% less compared with susceptible ones on nematode-free land. As few individuals of H. schachtii can overcome the resistance in the sugar beet, but not that of oil radish or mustard, a combination of methods will be discussed to overcome these disadvantages. 313 Durable resistance against Meloidogyne chitwoodi and M. fallax : a dream? G.W. K ORTHALS ¤ and L.P.G. M OLENDIJK Applied Plant Research, P.O. Box 430, 8200 AK Lelystad, The Netherlands ¤ G.W.Korthals@ppo.dlo.nl Final goal of EU-project DREAM (No. QLRT-1999- 1462: Durable resistance management of the soil-borne quarantine nematode pests Meloidogynechitwoodi and M. fallax ) is to deliver crops (potato as well as green manure crops) which are resistant against the root-knot nematodes M. chitwoodi and M. fallax . This poster presents the rst results of a comparison of 15 different genotypesof Italian ryegrass, fodder radish and potato. These 15 genotypes were previously selected with colleagues from Plant Research International, Barenbrug Holding BV and P.H. Petersen Saatzucht. The host suitability of the selected genotypes was determined by extracting nematodes from soil before planting (May 2001) and after the growing season (November 2001). First results on M. chitwoodi showed that on average the genotypes of fodder radish and potato proved to be more resistant compared to all tested genotypes of Italian ryegrass. However, none of the tested genotypes reduced the populations to zero, which was found after fallow. Meloidogyne fallax was able to reproduce much more on most genotypes, although three potato genotypes had a very low multiplication of M. fallax . 314 In uence of potato cultivars with different degrees of resistance on hatching and multiplication of the potato cyst nematode Globodera pallida Elizaveta M ATVEEVA 1 ; ¤ and Nicole V IAENE 2 1 Institute of Biology, Karelian Research Centre RAS, Pushkinskaya st, 11, Petrozavodsk, 185610, Karelia, Russia 2 Center of Agricultural Research, Department of Crop Protection, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ matveeva@bio.krc.karelia.ru Hatching of eggs of ve populationsof Globodera pallida in root diffusate of six potato cultivars was studied in vitro. All cultivars induced hatching, regardless of their degree of resistance to G. pallida . The percentage of hatched eggs after 7 weeks varied between populations and cultivars, but none of the cultivars consistently induced most or least hatch for all populations. Addition of freshly collected root diffusate (not stored) after 7 weeks of experiment resulted in a new ush of hatching and made differences between induction of hatching by the cultivars even more obscure. Results on the hatching of invasive juveniles are useful for estimating of the multiplication factor of nematode populations. Multiplication of all populations was highest on the susceptible cv. Bintje and lowest on the completely resistant cv. Innovator, but varied with population for partially resistant cvs Sante, Maritiema and Cycloon. Multiplication factors were higher and less variable in closed containers than in pots in the glasshouse, which facilitated discrimination between the cultivars. Test in closed containers could be used to advise farmers which cultivar to grow in G. pallida -infected elds. However, correlation between multiplication in closed containers and in the eld should be investigated. 315 Comparative study of two Heterodera avenae resistance genes from Aegilops ventricosa: differences in defence-enzymes induction and chromosomal location in wheat/ Ae. ventricosa introgression lines M. Jesús M ONTES 1 , Isidoro L ÓPEZ -B RAÑA 1 , M. Dolores R OMERO 2 , Esther S IN 3 , M. Fe A NDRÉS 2 , Juan A. M ARTÍN -S ÁNCHEZ 3 , Mariano G OMEZ -C OLMENAREJO 1 and Angeles D ELIBES 1 ; ¤ 1 Dpto de Biotecnología, ETS Ing Agrónomos, UPM, Ciudad Universitaria s/n, Madrid, E-28040, Spain; 2 Centro de Ciencias Medioambientales, CSIC, Serrano 115, Madrid, E-28006, Spain; 3 Centre R+D de Lleida, UdL-IRTA, Alcalde Rovira Roure 177, E-25198, Spain; ¤ adelibes@bit.etsia.upm.es Two independent introductions of genetic resistance to Heterodera avenae (Ha71 Spanish pathotype), from Aegilops ventricosa to hexaploid wheat were compared – the Cre2 (from Ae. ventricosa AP-1) and Cre5 Vol. 4(2), 2002 233</p>
<p>Resistance, breeding (295-335) (from Ae. ventricosa #10) genes. No susceptible plants were found in the F 2 progeny from the cross between both accessions of Ae. ventricosa suggesting that their respective resistance factors could be allelic. However, the genes Cre2 in H-93-8, and Cre5 in substitution 6D/6N v and addition 6N v lines have been transferred to different chromosome location. The induction of several defence responses during early incompatible interaction of resistant lines carrying Cre2 and Cre5 genes has also been studied. Isoelectrofocusing isozyme analysis revealed changes in peroxidase, esterase, superoxide dismutase, glutathionereductase, shikimat dehydrogenase and ascorbate peroxidase activities in infected roots of resistant lines in comparison to their susceptible parents. The highest differential activity between infected and uninfected roots was found for the peroxidase system, implicated in ligni cation process. A DNA marker, lacking in 6N v line, was linked to Cre2 gene in H-93-8. Differences observed between Cre2 and Cre5 genes with respect to the chromosomal location, detoxi cant enzymes induction, and behaviour against different pathotypes, suggests that they are different CCN resistance sources for wheat. 316 Comparative histology of feeding sites of Meloidogyne artiellia and M. javanica Mishael M OR Department of Nematology, Agricultural Research Organization, Volcani Center, P.O.B 6, Bet-Dagan 50-250, Israel mormi@volcani.agri.gov.il The root-knot nematode Meloidogyne artiellia causes considerable damage to several agricultural crops in the Mediterranean region. Microscopic examination of longitudinal root sections from two cruciferous plants, Brassica oleacea L. (cabbage) and B. rapa L. (turnip), infected with M. artiellia , revealed that the feeding sites consist of several large nurse cells in the central vascular tissues, which includes the companion cells. The intracellular organisation of these cells closely resembled the syncytial forms. The feeding zone cells showed hypertrophy and hyperplasia and intense vacuolisation. Also, different degrees of cell wall dissolution between contiguous cells were observed and only few cell nuclei and nucleoli were observed, all signi cantly enlarged and amoeboid, as compared to those in the feeding cells induced by Meloidogyne javanica . The feeding sites formed by M. artiellia differed considerably from the multinucleated giant cells (coenocyte) formed by M. javanica infection on these plants. The formation of a syncytium-like feeding site by root-knot nematodes is a highly unusual phenomenon. 317 Engineering coffee for root-knot nematode resistance using cysteine and serine proteinase inhibitors Roxana Myers 1 ; ¤ , Brent S IPES 1 , Chifumi N AGAI 2 , Donald S CHMITT 1 and Howard A TKINSON 3 1 University of Hawaii at Manoa, Plant and Environmental Protection Sciences, 3190 Maile Way, St. John 309, Honolulu, HI 96822, USA 2 Hawaii Agriculture Research Center, 99-193 Aiea Heights Drive, Suite 300, Aiea, HI, 96701-3911, USA 3 University of Leeds, Centre for Plant Biochemistry and Biotechnology, Leeds, LS2 9JT, UK ¤ roxana@hawaii.edu In Hawaii, the Kona coffee root-knot nematode, Meloido- gyne konaensis , causes severe damage to Coffea arabica cv. Typica. Due to the lack of resistant cultivars of C. ara- bica , genetic engineering for nematode control was ex- plored. The modi ed rice cystatin gene, OcI-ÄD86, and the dual proteinase inhibitor gene, OcI-ÄD86/GO/CpTI, were used to produce transgenic coffee for resistance to M. konaensis . Leaf discs were transformed using Agrobacterium tumefaciens containing the cystatin con- structs, then placed on G418 selection medium. The 38% that formed primary callus was presumed to be trans- formed. Somatic embryos have not yet been obtained from this callus because embryogenesis in coffee takes 7-9 months. In a second trial, somatic embryos were ob- tained from untransformed leaf discs. A. tumefaciens was used to transform the embryos with the two gene con- structs. Secondary embryos were produced in 37% of the initial experiments under G418 selection. In addition, em- bryogenic calli or somatic embryos were also transformed using particle gun bombardment. Within 6 weeks, sec- ondary embryos were produced from the bombarded em- bryos, while embryogenic calli only produced more calli. These results indicate that somatic embryos are the most ef cient target tissue in the production of transgenic cof- fee. 318 Differential gene expression between avirulent and virulent Meloidogyne incognita isogenic lines as monitored by cDNA-AFLP 234 Nematology</p>
<p>Poster sessions Cédriv N EVEU , Pierre A BAD and Philippe C ASTAGNONE -S ERENO ¤ INRA Unité IPMSV, BP2078, 06606 Antibes cédex, France ¤ pca@antibes.inra.fr Using two pairs of near-isogenic M. incognita lines, avirulent and virulent against the tomato Mi resistance gene, a cDNA-AFLP differential analysis was initiated, in order to identify genes differentially expressed between avirulent and virulent nematodes. AFLP markers were developed on cDNA templates digested with Hind III and Mse I, with all of the 256 combinations that could be generated with primers with two selective nucleotides. A total of approximately 84 000 fragments were ampli ed, among which 61 appeared differential ( i.e ., present in the two avirulent lines and absent in the two virulent lines). In order to con rm this result, cDNA-AFLP was run again on the same templates, but with all of the 64 combinations that could be generated with primers with two selective nucleotides for Mse I and one selective nucleotide for Hind III. This allowed elimination of a number of false positive bands, and 19 fragments differential between avirulent and virulent lines were thus selected for further analysis. The next experimental steps included cloning of the full-length genes, RT-PCR experiments, etc . The results will be discussed in relation with the ability of the nematode to overcome or not the plant resistance gene. 319 Differential gene expression in nematode resistant soybean genotypes Júlio C. P EDROSO 1 ; ¤ , Alexandre L. N EPOMUCENO 2 , João Flávio V ELOSO S ILVA 2 , Newton P. C ARNEIRO 3 , Poliana K. M ARTINS 1 , Michele C. B RETON 1 , Silvana R.R. M ARIN 2 and Eliseu B INNECK 2 1 Universidade Estadual de Londrina 2 Embrapa Soja 3 Embrapa Milho & Sorgo, Brazil ¤ Julio@cnpso.embrapa.br Meloidogyne javanica causes signi cant losses to soy- bean production in Brazil. Understanding how resistant plants respond to nematode infection at molecular level might indicate new strategies for the development of re- sistant genotypes. Roots of soybean genotypes, BRS-133 (susceptible) and PI595099 (resistant), were analysed for differential gene expression during nematode infection. At 5 days after germination, both genotypes were infected with nematode eggs and juveniles. Root samples were col- lected at 9 and 12 days. Total RNA was extracted from the roots and the Differential Display (DD) technique was used to identify and isolate genes that differ between the genotypes during nematode infection. Differentially ex- pressed genes were identi ed, isolated and cloned into pGEM-T vectors for sequencing. Differentially expressed gene sequences were used to search for homologies. Pre- liminary analysis identi ed homology with a nucleotide binding protein, a pathogenesisrelated protein, a low tem- perature and salt responsive protein, an aquaporin protein, and transcription factors. 320 Evaluation of maize genotypes for resistance against Meloidogyne javanica and M. incognita race 3 Neucimara Rodrigues R IBEIRO 1 , João Flávio V ELOSO S ILVA 1 ; ¤ , André F RANCISCO 2 , José G OMES 2 and Walter Fernandes M EIRELLES 3 1 Embrapa Soja; 2 FAPEAGRO; 3 Embrapa Milho & Sorgo CP 231, 86001-970, Londrina, PR, Brazil ¤ veloso@cnpso.embrapa.br The use of nematode resistant crops in rotations prevents losses in susceptible crops. In Brazil corn is the main crop used in rotation with soybean. The reproduction of Meloidogyne javanica and M. incognita race 3 was studied in 176 and 57 maize genotypes, respectively. The plants were grown in glasshouse conditions, inoculated with 5000 nematode eggs and evaluated after 60 days. Tomato plants were used as an inoculum ef ciency check. The egg production of M. incognita was higher than M. javanica in all maize genotypes. Meloidogyne javanica presented low reproduction in 78 genotypes. Only the genotypesBRS 2114, P 30F80 and AG9090 were resistant to M. incognita , resulting in low egg production. 321 Host suitability in soybean cultivars for the reniform nematode, 2001 tests R.T. R OBBINS 1 , L. R AKES 1 , L.E. J ACKSON 1 , E.R. S HIPE 2 , E.E. G BUR 3 and D.G. D OMBEK 4 1 Cralley-Warren Center, 2601 N. Young Avenue, Fayetteville, AR 72704, USA 2 Clemson University, Poole Agric. Center, Box 340359, Clemson, SC 29634-0359, USA 3 Agricultural Statistics Laboratory, University of Arkansas, Fayetteville, AR, 72701, USA 4 Arkansas Crop Improvement Program, 313 Cassatt Road, Fayetteville, AR, USA Vol. 4(2), 2002 235</p>
<p>Resistance, breeding (295-335) In 2001 glasshouse pot experiments, 139 soybean varieties from the Arkansas and Mississippi variety testing programs (119) and varieties submitted by Louisiana extension nematologists (20) and 34 breeding lines from Clemson University were tested to determine their suitability as hosts for the reniform nematode, Rotylenchulus reniformis . The R. reniformis -resistant varieties Forrest and Hartwig, the susceptible variety Braxton, and fallow- R. reniformis -infested soil served as controls. Total number of eggs and nematodes extracted from both the soil and roots from each pot, reproductive indices ( RI D Pf=P i ), RI=RI of Forrest ( RF ), log ratio . log 10 .RF C 1 // , and RF calculated from log 10 .RF C 1 / were calculated for each cultivar or breeding line in each test. Varieties with RF signi cantly greater than the RF on Forrest (1.00) were considered suitable hosts for R. reniformis . In the states variety test, 90 of the 119 varieties were suitable hosts when RF were compared and 117 when the log ratio . log 10 .RF C 1 // were compared. In the Clemson test, 23 of the 34 varieties and breeding lines were suitable hosts when RF were compared, and 24 when the log ratio . log 10 .RF C 1 // were compared. 322 Characterisation of resistance to root-knot nematodes in carrot Philip A. R OBERTS 1 ; ¤ , P.W. S IMON 2 , L.S. B OITEUX 3 , W.C. M ATTHEWS 1 and T.R. M ULLENS 1 1 Department of Nematology, University of California, Riverside, California 92521, USA 2 USDA, ARS Vegetable Crops Research Unit, Department of Horticulture, University of Wisconsin, Madison, Wisconsin, USA 3 Centro Nacional de Pesquisa de Hortaliças (CNPH)/Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), CP 218, 70359-970 Brasília-DF, Brazil ¤ philip.roberts@ucr.edu Host plant resistance to the root-knot nematodes Meloi- dogyne javanica and M. incognita conferred by the Mj-1 locus is being incorporated into advanced breeding lines of carrot ( Daucus carota ). Genetic analysis of F2-F4 and BC families determined that the resistance is inherited as a single dominant gene or possibly two closely linked genes. The Mj-1 locus is derived from the variety Brasilia, and it expresses very high levels of resistance to M. ja- vanica and almost as high resistance to M. incognita . To improve the selection ef ciency for the Mj-1 locus in breeding programs, closely linked STS codominant ank- ing markers have been developed. Application of these markers helped to con rm phenotypic separation of ho- mozygous and heterozygous resistant plants. Heterozy- gous plants had similar levels of resistance to root-galling symptoms, but supported higher nematode reproduction compared with homozygous plants. This gene dosage ef- fect was more apparent against M. incognita than M. ja- vanica , and at temperatures of 28 ± C or higher, when Mj- 1 expression was weaker. Effective resistance was shown in eld experiments when used alone and in combination with other cultural tactics, including use of rotation crops with resistance and manipulation of carrot planting date to minimise infection. 323 New sources of resistance to Rotylenchulus reniformis in cotton, Gossypium spp. Forest R OBINSON , A. Edward P ERCIVAL and Alan C. B RIDGES 2765 F&B Rd, College Station, TX 77845, USA Rotylenchulus reniformis causes yield losses to cotton ( Gossypium hirsutum ) in Mississippi, Louisiana and Alabama in the USA. Crop rotation and nematicides are marginally economic and resistance is needed but only weak resistance is reported in G. hirsutum , and all previous studies represent a small percentage of accessions available within Gossypium species. We evaluated ca 3000 primitive accessions of G. arboreum , G. herbaceum , G. longicalyx , G. hirsutum and G. barbadense from the US National Cotton Collection and con rmed resistance to R. reniformis in the diploid species G. arboreum , G. herbaceum and G. longicalyx . No resistance was found in more than 1500 accessions of G. hirsutum . Several of more than 1000 accessions of the compatible tetraploid G. barbadense were resistant; others were comparable to susceptible controls; none were immune. Resistant G. barbadense were collected in widely scattered regions: Peru, Guatemala, Mexico and St Lucia. The G. barbadense accession GB-713 had the highest resistance, followed by a second group (GB-49, GB-264, TX-110), and a third group that was weakly but consistentlyresistant (TX-1347, TX-1348). Differences in origin and resistance level suggest further enhancement of resistance may be gained through new combinations of resistance genes. 324 Effects of temperature and soybean genotype on Heterodera glycines males and females population 236 Nematology</p>
<p>Poster sessions M.R. D A R OCHA 1 ; ¤ , T. A NDERSON 2 and T. W ELACKY 2 1 Univ. Fed. de Goiás, Esc. de Agronomia, Caixa Postal 131, CEP 74001-970, Goiania, GO, Brazil 2 Agriculture and Agri-Food Canada, Greenhouse and Processing Crops Research Centre, N0R1G0, Harrow, Ontario, Canada ¤ mrocha@agro.ufg.br Soybean cyst nematode resistant ‘Bell’ and susceptible ‘S 20-20’ soybean cultivars, were pre-germinated and transplanted to Heterodera glycines infested soil, and exposed to temperatures of 20, 25, 30 or 35 ± C for 10 days in growth chambers. Males were counted from plants growing hydroponicallyfor 10 additional days and females were counted from plants growing in autoclaved sand for 30 additional days. The male:female ratios were always higher than one and higher on the resistant cv. Bell. Infection by males and females was affected by temperature and was highest between 26 and 28 ± C. Total male population was not affected by soybean genotype. More abnormal males ( < 800 ¹ m) developed on roots of the resistant cv. Bell and shorter males developed following exposure at 35 ± C. The female population was signi cantly higher on the susceptible cv. S 20-20. At 35 ± C only a few females developed on both cultivars, which led to a higher male:female ratio. The number of eggs/female was higher on susceptible S 20-20 than on resistant Bell and did not differ signi cantly with different temperatures. 325 Response of pepper stocks to Meloidogyne incognita in glasshouses in the southeast of Spain C. R OS 1 , M.M. G UERRERO 2 , P. G UIRAO 1 , A. L ACASA 2 ; ¤ , M.A. M ARTÍNEZ 2 , J. T ORRES 2 , N. B ARCELÓ 2 and A. G ONZÁLEZ 2 1 FECOAM – Consejería de Agricultura, Agua y Medio Ambiente, C/Caballero, 13, 30.002 Murcia, Spain 2 Protección Vegetal, Centro de Investigación y Desarrollo Agroalimentario, CAAMA, C/Mayor s/n, 30.150 La Alberca, Murcia, Spain ¤ Alfredo.Lacasa@ carm.es Commercial pepper varieties resistant to Meloidogyne incognita did not match the standard production of glasshouses in the southeast of Spain. When methyl bromide (MB) is not used for soil disinfection, nematodes become one of the main soil-borne pathogens. The response of 75 resistant pepper stocks was tested against Phytophthora capsici and M. incognita in relation to non- resistant varieties grown on MB disinfected soils. More than 30% of the stocks assayed had average root-knot index similar to those of MB treatments. More than 30% of the stocks had also marketable yields (8.3 kg/m 2 C-58 hybrid; 8.0 kg/m 2 C-57 and 8.2 kg/m 2 C-30) similar to those of MB treatments (8.9 kg/m 2 / . Stocks grown on the same soil over 3 years led to an increase of aggressiveness in M. incognita populations. This was noticed by an increase in average root-knot index and the percentage of infested plants ( i.e ., in the 1st year the C-30 hybrid had 0.1% of infested plants and 0.1 of root-knot index, while in the 2nd year 73.3% of the plants were infested and the root-knot index increased to 4.1). 326 Identi cation of markers to facilitate cloning of resistance genes to Heterodera trifolii in clover Garry M. R OSEWARNE ¤ , P.J. L ARKIN and E.S. L AGUDAH Plant Industry, CSIRO, GPO Box 1600, Canberra ACT 2601, Australia; ¤ garry.rosewarne@csiro.au White clover ( Trifolium repens ) is a major legume component of dairy pastures throughout Australia. However these plants are susceptible to a variety of root endoparasitic nematodes, the most common and widespread being Heterodera trifolii . Nematodes can severely affect productivity and incur substantial losses to the dairy industry. There is little resistance to H. trifolii in white clover, although we have identi ed resistance in caucasian clover, Trifolium ambiguum . Conserved sequences of previously characterised resistance genes and their analogs are being used to identify candidate resistance genes in T. ambiguum . Partial sequences of resistance gene analogs (RGAs) have been isolated from legumes using DNA sequence databases and through a PCR approach with white clover. Over 200 RGA sequences from legumes have been analysed phylogenetically and 39 sequences selected to represent distinct clusters. These individual sequences were used as probes in a bulk segregant analysis of T. ambiguum plants that are either resistant or susceptible to H. trifolii . Probes that reveal polymorphism and where subsequent analysis of individuals shows a tight linkage to the resistance phenotype will be targeted. Diagnostic probes provide an entry point to screen a resistant T. ambiguum genomic library to identify candidate resistance genes for use in transformation experiments. Vol. 4(2), 2002 237</p>
<p>Resistance, breeding (295-335) 327 Identi cation of resistance to the oat race of stem nematode ( Ditylenchus dipsaci ) in faba bean ( Vicia faba ) in Australia Sharyn T AYLOR 1 ; ¤ , Maria S CURRAH 2 and Danuta S ZOT 1 1 South Australian Research and Development Institute, GPO Box 397, Adelaide, South Australia 5001, Australia 2 International Potato Centre, Apartado 1158, Lima, Peru ¤ taylor.sharyn@saugov.sa.gov.au The oat race of stem nematode ( Ditylenchus dipsaci ) was rst recorded in South Australia in 1973. The principal hosts in this region are oats and faba beans and the only economic method for control is the use of resistant crops/varieties within rotations. At the commencement of research in 1994, high levels of resistance and tolerance were identi ed in oat breeding material and screening has contributed to the release of ve resistant and tolerant oat varieties. In contrast, of the 120 advanced faba bean lines tested, only low to moderate levels of resistance were found. Variation was observed within the commercial cultivars Fiord and Ascot, however, and crosses from plants showing superior resistance were made. Lines from progeny of crosses from Ascot produced accessions with moderate to high levels of resistance and from Fiord with moderate resistance following recurrent selection from 1994 to 2000. These selections represent a signi cant improvement on existing material and will be used as parents to develop varieties with superior resistance for the South Australian Faba Bean Breeding Program. 328 Reaction of banana clones ( Musa spp.) to Meloidogyne incognita race 3 R.C.V. T ENENTE 1 , O.A. C ARRIJO 2 , S. Silva N ETO 3 , R.D.C. S ILVA 2 and G.T. C OSTA 2 1 Embrapa/Cenargen, C.P. 2372 (70770-900) Brasilia, DF, Brazil 2 Embrapa/CNPH, BR 060, Km 09 Rod. Brasilia/Anapolis (70359-970), Brasilia, DF, Brazil 3 CAMPO, Rodovia LMG 658 km (38.600-000) Paracatu, MG, Brazil The aim of this work was to study under glasshouse conditions the reaction of banana to Meloidogyne incognita race 3. These clones were developed by a Breeding Program of Embrapa Cassava and Tropical Fruits Center and Agriculture Promotion Company. Micropropagated offspring were used and 5 days after transplant to containers lled with sterilised soil C sand C manure, they were inoculated with 10 000 eggs. The experiment design was completely randomised with four replicates. After 120 days, the clones were evaluated by the egg number and presence of nematodes in root, using Nanicão 122 clone as the susceptibility standard, at two levels of watering. Soil samples were collected to determine the nematode number per 200 cm 3 per replicate for each clone. The Nanicão clones (90 and 122) allowed a large multiplication of M. incognita , compared with the other eight clones, showing susceptible reaction, but Maçã 57 showed the lowest parasite multiplication.All the other clones showed some nematode resistance, depending on the water level, and it can be seen in the results of Nanicão clones. For the root weight and aerial parts, the results showed little difference, compared with inoculated and non-inoculated plants, showing some difference between two levels of watering. 329 Resistance of watermelon ( Citrullus spp.) germplasm to the peanut root-knot nematode ( Meloidogyne arenaria race 1) Judy T HIES ¤ and Amnon L EVI US Vegetable Laboratory, ARS, USDA, 2875 Savannah Highway, Charleston, SC, 29414, USA ¤ jthies@awod.com Root-knot nematodes ( Meloidogyne arenaria , M. inco- gnita and M. javanica ) are serious pests of watermelon ( Citrullus lanatus ) in the southern US and world-wide. Currently, root-knot nematodes (RKN) are controlled in watermelon by pre-plant soil fumigation with methyl bro- mide or other nematicides. The proposed removal of methyl bromide from the US market in 2005 has focused interest in developing alternatives for managing nema- todes in vegetable crops. Resistant cultivars would pro- vide an inexpensive, environmentally compatible alterna- tive for managing RKN in watermelon. All accessions of C. colocynthis (21) and C. lanatus var. citroides (88), and approximately 10% of C. lanatus var. lanatus (157) ac- cessions from the USDA Citrullus germplasm collection were evaluated for resistance to M. arenaria race 1 in greenhouse tests. The C. lanatus var. lanatus and C. colo- cynthis accessions were susceptible with root gall sever- ity indices (GI) of 4.0-9.0 (scale, 1.0-9.0) and 8.0-9.0, re- spectively. However, 21 of 88 C. lanatus var. citroides ac- cessions were moderately resistant (GI, 3.0-9.0). Signi - cant genetic variability exists within the USDA Citrullus germplasm collection for reaction to M. arenaria race 1 238 Nematology</p>
<p>Poster sessions and the C. lanatus var . citroides accessions are potential sources of resistance to M. arenaria race 1. 330 Multiple selection and durability of potato cyst nematode Globodera pallida virulence on a range of potato species Susan J. T URNER ¤ and Colin C. F LEMING Applied Plant Science Division, Department of Agriculture and Rural Development for Northern Ireland, Newforge Lane, Belfast BT9 5PX, UK ¤ Sue.Turner@dardni.gov.uk A series of selection experiments on potato cyst nematode Globodera pallida , pathotype Pa1 tested the virulence response of the nematode to a range of resistant potato Solanum genotypes. Alleles conferring virulence against all four Solanum sources used in the study, i.e. , Solanum vernei, S. multidissectum, S. sanctae-rosae and S. tuberosum spp. andigena were detected. Selection for multiple virulence against a combination of resistant sources resulted in the originally selected virulence genes being retained or lost. The mechanism of potato cyst nematode resistance differs between the Solanum species. This, potentially, offers a management tool for controlling potato cyst nematode levels in infested potato land through the appropriate use of resistant cultivars produced from a range of Solanum -resistant species. Extended selection trials on a range of worldwide G. pallida populations clari ed that some Solanum species were more durable at maintaining their PCN resistance than others. After 5 years of continual selection of PCN populations on S. tuberosum spp. andigena no appreciable increase in virulence had occurred, whereas on S. stenotonum and S. kurtzianum , increased PCN reproduction rates were apparent from the second selected generation. These results have clear implications when selecting the most appropriate material for PCN breeding programmes. 331 Members of the root lipoxygenase gene family of susceptible and resistant pea genotypes exhibit distinct expression patterns when infected by cyst nematodes Pasqua V ERONICO ¤ , Donato G IANNINO , Maria Teresa M ELILLO and Teresa B LEVE -Z ACHEO Istituto di Protezione delle Piante, C.N.R., via Amendola 165/A, 70126 Bari, Italy ¤ pveron@libero.it Plant lipoxygenaseactivity is involved in plant growth and development by formation of fatty-acid hydroperoxides and/or jasmonic acid. Moreover, lipoxygenasesare known to contribute in regulating cell death and resistance to pathogenic agents. In order to understand the timing of lipoxygenase involvement during nematode infection, we characterised the expression pattern of ve genes coding for distinct lipoxygenase isoforms ( LOX s) in Pisum sativum resistant (line MG103738) and susceptible (cv. Progress9) to the cyst nematode Heterodera goettingiana . The expression pattern of the same LOX genes has also been evaluated in pea roots following wounding in the absence of the parasite. An increased expression of each lipoxygenase isoform, in both resistant and susceptible roots, 2 h after wounding with a peak of transcript abundance at 6 h was observed. Furthermore, in infected roots LOX expression was followed at 24, 48, and 72 h after nematode infection. The LOX s of susceptible and resistant pea roots exhibited distinct expression patterns indicating the occurrence of gene down- and up- regulation. Intriguingly,some LOX members were clearly repressed during nematode infection in the resistant genotype. 332 The in uences of different soybean cultivars on the dynamics of Heterodera glycines race 3 Haiyan W U ¤ , Yuxi D UAN , Lijie C HEN and Weizhi L IU College of Plant Protection, Shenyang Agricultural University, Shengyang, 110161, P. R. China ¤ Wuhy11@263.net.cn Nine cultivars were used to study the dynamics of soybean cyst nematode (SCN) Heterodera glycines race 3 for different soybean cultivars in the eld of Shenyang Agricultural University, Liaoning province in China. The results indicated that the numbers of SCN second stage juveniles (J2) in the rhizosphere of Liaodou 10 reached its highest peak, 60.4 J2, in 100 cm 3 soil, on 24 May. The cyst population of soil around the root of Liaodou 10 and Kaiyu 10 had a peak on 6 June (23.3 and 30.0 cysts in 100 cm 3 soil, respectively), which was 1.5 to 2.0 times the number on Peking. There was a peak of J2 in the root of soybean on 24 May for the resistant cultivars PI90763, Harbin small black soybean, Yingxian small black soybean and Franklin, but the peak value was much lower than that of Liaodou 10 and Kaiyu 10. From the dynamics of J2, J3 and J4, soybean LiaoK89102 was Vol. 4(2), 2002 239</p>
<p>Resistance, breeding (295-335) resistant to invasion by SCN, PI90763 was resistant to development of SCN, Liaodou 10 and Kaiyu 10 were susceptible cultivars. 333 Selection of root-knot nematode resistant sugar beet from eld plantings M.H. Y U 1 ; ¤ and P.A. R OBERTS 2 1 USDA, Agricultural Research Service, Salinas, California 93905, USA 2 Department of Nematology, University of California, Riverside, California 92521, USA ¤ myu@pw.ars.usda.gov Sugar beet is a favoured host for numerous species of nematodes, including Meloidogyne spp. Resistance to root-knot nematodes was identi ed 7 years ago, and since then it has been introgressed into cultivated sugar beet. Preliminary observations on several breeding populations were conducted in eld plots infested with either M. incognita or M. javanica at UC Research and Extension Centers, Irvine and Parlier, California. In resistant progeny families, more than 50% of the plants produced healthy taproots that exhibited no root-knot symptoms. In comparison, none of the susceptible control plants were free from galling. Signi cant reductions of approximately 45% or more in root weights occurred when these susceptible control plants were grown in infested soil. Susceptible sugar beet suffered a higher sensitivity reaction to prolonged temperature ( > 38 ± C) stresses and secondary pathogenic invasions than the resistant counterpart. Glasshouse inoculation screenings provided reliable classi cation of resistant genotypes, but no index of full growth potential of the plants. Our results indicate that a productive root-knot nematode-resistant sugar beet line with elite root yield, taproot conformation, and sucrose content would be developed more readily when resistant parents were grown and selected from nematode infested elds. 334 Resistance of Aegilops geniculata Roth to cereal cyst nematode ( Heterodera avenae ) and root lesion nematode ( Pratylenchus thornei ) Maria Z AHARI EVA 1 ; ¤ , Julie N ICOL 2 , Higinio R OMERO 3 and Roger R IVOAL 4 1 CIMMYT, Wheat Program, A.P. 6-641, 06600 Mexico D.F., Mexico 2 CIMMYT International, Wheat Program, PO Box 39, Emek, 06511, Ankara, Turkey 3 Universidad Autónoma Chapingo, Chapingo, México 4 UMR INRA/ENSAR, Biologie des Organismes et des Populations appliquée à la Protection des Plantes (BiO3P), BP 35327, 35653 Le Rheu, France ¤ m.zaharieva@cgiar.org Wild wheat relative Aegilops geniculata represents a valuable source of genetic variation for improvement of disease and pest resistance in cultivated wheat ( Triticum aestivum ). A better understanding of the resistance responses of this species against cereal cyst nematode (CCN) and root lesion nematode (RLN) is needed. Ae. geniculata accessions originating from different eco- geographical regions possessing useful biotic and abiotic stress resistance traits were evaluated for their reaction to two populations of CCN Heterodera avenae : Ha41 originated from France and E125 from Syria, and to one population of RLN Pratylenchus thornei from Mexico. Results obtained con rmed the potential value of Ae. geniculata as a source of CCN resistance for wheat improvement. They also demonstrated the interest of this species as a source of moderate resistance to P. thornei. Promising Ae. geniculata accessions possessing resistance traits to cereal cyst and/or root lesion nematodes in addition to other abiotic/biotic stresses were identi ed and are presently used in wide hybridisation programme. They were crossed with susceptible high- yielding bread and durum wheat CIMMYT cultivars as well as with Chinese Spring in order to transfer this resistance into cultivated wheat. 335 Durable resistance against Meloidogyne chitwoodi and M. fallax (EU-DREAM) F.C. Z OON 1 ; ¤ , J. B AKKER 2 , W. G OLINOWSK 3 , R. J ANSSEN 1 , D. M UGNIÉRY 4 , M.S. P HILLIPS 5 , M. S CHLATHÖLTER 6 , J.G. VAN DER B EEK 1 and L. VAN K RUIJSSEN 7 1 Plant Research International, P.O. Box 16, NL-6700 AA Wageningen, The Netherlands 2 Laboratory of Nematology, Wageningen University, Wageningen, The Netherlands 3 Department of Botany (SGGW), Warsaw Agricultural University, Warsaw, Poland 4 Laboratoire de Zoologie, INRA, Le Rheu, France 5 Dept Nematology, SCRI, Dundee, Scotland, UK 6 P.H. Petersen Saatzucht GmbH, Grundhof, Germany 7 Barenbrug Research BV, Wolfheze, The Netherlands ¤ f.c.zoon@plant.wag-ur.nl 240 Nematology</p>
<p>Poster sessions The EU-funded project QLRT-1999-1462 DREAM (Du- rable Resistance Against Meloidogyne ) aims to contribute to sustainable production systems by developing a strat- egy for durable resistance management for these soil- borne pests. This study focuses on the two polyphagous quarantine-organisms Meloidogyne chitwoodi and M. fal- lax , which are an important economic threat and for which no adequate durable alternative exists. The objec- tive will be achieved by integrating expertise in breed- ing, nematology, botany and molecular biology into one project, novel by its European dimension. The project combines three areas of research: i ) identi cation and incorporation of resistance in important arable crops: potato, pepper, ryegrass and fodder radish, ii ) study of variation in nematode virulence and of durability of the resistance, and iii ) optimising of production systems by rotation schemes. The main results expected are: resistant germplasm, well characterised pathogen collections, reliable selection and breeding methods, knowledge on the stability of resistance, molecular markers linked to resistance and (a)virulence, knowledge on resistance mechanisms and genes, genetic maps, and advice about improved rotation schemes. More information and rst results can be found at www.eu-dream.nl. Vol. 4(2), 2002 241</p>
<p>Morphology, development (336-358) 336 Molecular characterisation and morphometrics of cereal cyst nematodes in Syria and Turkey Hussam A BIDOU 1 , Sylvie V ALETTE 2 , Jean-Pierre G AUTHIER 2 , Roger R IVOAL 2 and Amor Y AHYAOUI 3 1 University of Aleppo, Faculty of Agriculture, PO Box 12009, Aleppo, Syria 2 UMR INRA/ENSAR, Biologie des Organismes et des Populations appliquée à la Protection des Plantes (BiO3P), BP 35327, 35653 Le Rheu, France 3 ICARDA, Cereal Pathology, PO Box 5466, Aleppo, Syria. Cereal cyst nematodes (CCN) are becoming serious cereal disease in the rainfed areas of the Mediterranean basin. A survey of cereal elds in Syria and Turkey has shown that the main cereal cyst nematodes Heterodera avenae , H. lipjevi and H. latipons occur frequently. Characterisation of these nematodes was conducted on 14 populations using PCR-RFLP analysis of the ITS regions of rDNA and on 12 morphometric characters of cysts and juveniles tested through a principle component analysis (PCA). Restriction patterns obtained with four endonucleases( Hae III, Hin fI, Ita I, Pst I) enabled differentiation of the three cited species plus the chick-pea cyst nematode Heterodera ciceri . Principal component analysis applied to the morphometrical parameters followed by a direct hierarchical classi cation con rmed the molecular diagnostics but demonstrated a substantial variability in the H. latipons group. 337 Ultrastructural and histological changes induced by Rotylenchulus reniformis in resistant and susceptible upland cotton Paula A GUDELO 1 ; ¤ , Robert T. R OBBINS 1 , Kyung S. K IM 1 and James McD. S TEWART 2 1 217 Plant Science, University of Arkansas, Fayetteville, AR 72701, USA 2 Crop Soil & Environmental Science, University of Arkansas, Fayetteville, AR 72701, USA ¤ pagudel@uark.edu Several events that may determine the degree of susceptibility of cotton plants to reniform nematode occur at the feeding site. The objective of this work is to describe histological and ultrastructural modi cations induced by Rotylenchulus reniformis in resistant and susceptible upland cotton ( Gossypium hirsutum ) roots. Susceptible (Deltapine50) and resistant cotton materials under evaluation were inoculated with reniform nematode in the glasshouse. Fifteen days after inoculation, roots were washed and prepared for observation. Tissues were xed in Karnovsky and post- xed in 1% osmium tetroxide. They were pre-stained in 0.5% uranyl acetate, dehydrated, and embedded in Spurr. Thin sections were prepared and stained for observation under transmission electron microscope. Additionally, thick sections were prepared and stained for observation under light microscope. Both susceptible and resistant plants, formed syncytia with cell wall perforations, dense cytoplasm, increased endoplasmic reticulum, and increased size of nucleus. Changes that appear to be induced in plants with a higher level of resistance include a layer of necrotic cells surrounding the syncytia and prominent cell wall appositions in syncytium component cells near the necrotic layer. 338 Morphometric variation of Rotylenchulus reniformis geographic populations from cotton-growing regions in the United States Paula A GUDELO and Robert T. R OBBINS 217 Plant Science, University of Arkansas, Fayetteville, AR 72701, USA pagudel@uark.edu The variability of morphological characters among populations of Rotylenchulus reniformis associated with cotton plantations in the United States is not known. A study was conducted to determine the range of variability of diagnostic characters in males and immature females among 12 populations from different cotton-growing regions in the United States (two from Alabama, two from Arkansas, one from Florida, one from Georgia, two from Hawaii, one from Louisiana, one from Mississippi, one from South Carolina, and one from Texas). Specimens were extracted from soil by the centrifugation- otation technique, and were heat narcotised. Nematodes were mounted in water and measured with the aid of a compound microscope. Analysis of variance was used to compare the characters measured among populations. Morphometrics of males and immature females from the different geographic regions of the southeastern United States were similar, but differed from those from Hawaii. The effect of the host on the range of variability of diagnostic characters was also determined by comparing measurements of the populations grown on tomato (Rutgers), cotton (Deltapine 50), and soybean (Braxton). 242 Nematology</p>
<p>Poster sessions 339 The cellular structure of the female reproductive system of Meloidogyne spp. compared with other nematode species Wim B ERT 1 ; ¤ , Ruben V AN G ANSBEKE 1 , Gerrit K ARSSEN 2 , Gaetan B ORGONIE 1 and Etienne G ERAERT 1 1 Department of Biology, Ghent University, Ledeganckstraat 35, B-9000 Gent, Belgium 2 Plant Protection Service, Nematology Section, P.O. Box 9102, 6700 HC Wageningen, The Netherlands ¤ wim.bert@rug.ac.be Gonads from living young females, belonging to 15 Meloidogyne species and 80 other species, were extruded to study the cellular structure of the female genital structure. Within the genus Meloidogyne , the spermatheca is always spherical and formed by a variable number of thick, lobe-like cells, which makes it different from any other known nematode genus. Members of this genus are strongly uni ed by this characteristic anatomical feature. Nevertheless a remarkable intrageneric variability is demonstrated; most species have 16 to 18 spermatheca cells with interlaced cell boundaries while M. microtyla and M. ichinohei have more spermatheca cells with atypical cell boundaries and the spermatheca cells of the M. fallax specimens are clustered together forming lobes. While most species were studied with light microscopy, the gonads of M. incognita were studied thoroughly using scanning and transmission electron microscopy. This allowed us to determine exactly the structural separate gonoduct components and have a better insight in their action and function. 340 Eggshell ultrastructure of Heterodera glycines : histochemical localisation of chitinous components B. B URGWYN ¤ , B. N AGEL , J. R YERSE and R.I. B OLLA Biology Department, Saint Louis University, St Louis, MO, USA ¤ burgwynh@slu.edu The function of the nematode eggshell to protect the developing embryo is well conserved; however, the structure of the eggshell is varied. The most common structure that is found amongst nematodes is a tri-layer ultrastructure composed of a lipid layer, a chitin layer, and a vitelline layer. Previous literature on the ultrastructure of the Heterodera glycines eggshell has claimed that there is no vitelline layer but rather two chitinous layers. It is our contention that the outer chitin layer described in past literature is actually a vitelline layer. Histochemical analysis has demonstrated a lack of chitinous material on the eggshell exterior. Microscopy observations of the eggshell shows a waxy appearance and osmotic staining that is consistent with that of the vitelline layer found in other nematodes. Lectin localisation has also shown that the eggshell continues to develop past fertilisation with delivery and integration of eggshell precursors. Further, a ‘zipper like’ structure associated with the vitelline layer of the eggshell for juvenile emersion was observed. Based on our ndings we propose that H. glycines follows the common three-layer structure of other nematodes and is not an exception as originally thought. 341 AFM pro ling of putative hydrogen bond patterns on nematode cuticle surface Aurelio C IANCIO Istituto per la Protezione delle Piante, Consiglio Nazionale delle Ricerche, Via Amendola 165/A, 70126 Bari, Italy ciancio@area.ba.cnr.it Atomic Force Microscopy (AFM) is a non-invasive high- resolution probe microscopy useful in the study of biolog- ical surfaces in their quasi-nativestate. Applications to ne- matode cuticle from dried specimens showed that atomic resolution studies are feasible, allowing the identi cation of structural arrangements of single collagen chains. AFM scannings were applied to air or ethanol dried Xiphinema diversicaudatum specimens. After scanning stabilisation during long-run sessions at room temperature and pres- sure, atomic resolution images allowed the reconstruction of molecular level details. These included ordered pat- terns of drop-like clouds linking parallel atom chains in- terpreted as putative H-bonds. Their length, shape and di- mensions, as well as the ratio with the other particle mea- surements, t quantum models of charge distribution as well as Bohr’s ‘hanging drop’ model of H-bonds. These are the rst atomic resolution data obtained from nema- tode cuticle and the rst imaging of a putative chemical bond produced by AFM. The potential of this technology in high resolution studies of biomolecules is discussed. 342 Morphobiometrical and biochemical characterisation of Heterodera zeae Portuguese populations Fernando J.S. C ORREIA ¤ and Isabel M. de O. A BRANTES Vol. 4(2), 2002 243</p>
<p>Morphology, development (336-358) Instituto do Ambiente e Vida, Departamento de Zoologia, Universidade de Coimbra, 3004-517 Coimbra, Portugal ¤ nemz@zoo.uc.pt Three populations of Heterodera from different locations in Portugal were isolated from g tree rhizosphere and corn roots. Morphological and morphometrical analysis revealed that all populations presented the two main diagnostic characters of the corn cyst nematode, Heterodera zeae : i ) the unique two level bullae with characteristic arrangement and orientation; and ii ) stylet mean length usually smaller than 20 ¹ m. The morphology (LM, SEM) and morphometry of cysts and second- stage juveniles are given and the intrapopulational and intraspeci c variability are discussed and compared with other populations. Furthermore, a characteristic and reproducible phenotype of nonspeci c esterase activity was detected, by native polyacrylamide gel electrophoresis, in the three populations. The occurrence of H. zeae , an economically signi cant parasite and originally identi ed from corn ( Zea mays L.), is reported for the rst time in Europe (Portugal). 343 A comparative study of amphimictic populations of lesion nematodes with two lip annuli from citrus, coffee, yam, and banana in Brazil Anderson S. DE C AMPOS 1 , Jaime M. DOS S ANTOS 2 ; ¤ , Larry W. D UNCAN 3 and Renato N. I NSERRA 4 1 ; 2 UNESP/Faculdade de Ciências Agrárias e Veterinárias, Via de Acesso Prof. Paulo Donato Castellane s/n, 14884.900 Jaboticabal, SP, Brazil 2 Univ. of Florida – IFAS, Citrus Research and Education Center, University of Florida, 700 Experiment Station Rd, Lake Alfred, FL 33850, USA 3 Florida Dept. of Agriculture, Division of Plant Industry, P.O. Box 147100, Gainesville, FL 32614-7100, USA ¤ jmsantos@fcav.unesp.br A collection of 17 amphimictic populations of Praty- lenchus spp. with two lip annuli collected from Dioscorea cayenensis Lam., Musa sp., Coffea arabica L. (one from each), and Citrus limonia L. Osbeck (13 populations) has been maintained on their hosts in a glasshouse at the UN- ESP Campus at Jaboticabal, SP, Brazil. A comparative study was done on all populations with the exception of eight from citrus, using 21 morphologic, morphometric and derived variables obtained using SEM and light mi- croscopy. The populations from yam and banana were identi ed as Pratylenchus coffeae (Zimmermann) Filip- jev & Schuurmans Stekhoven. All others pertain to a new species found on citrus in São Paulo State that is being de- scribed and named P. jaehni. A cluster analysis of stylet length, width and height of the stylet knobs, a, b, c, c 0 and V parameters for these populations was consistent with the identi cations. 344 Scanning electron microscopy of the juvenile stages of some Wilsonematinae (Plectidae) Irma T. D E L EY 1 ; ¤ , Oleksandr H OLOVACHOV 2 and Paul D E L EY 1 1 Department of Nematology, University of California – Riverside, Riverside CA 92521, USA 2 Department of Zoology, Biological Faculty, Ivan Franko National University of L’viv, Grushevsky str. 4, L’viv 79005, Ukraine ¤ itdeley@citrus.ucr.edu Lip regions of Tylocephalus auriculatus and Ereptonema arcticum undergo extensive morphological transforma- tions during the nematodes developmental stages, from a simple Plectus -like appearance to a much more com- plex set of anterior structures. We present the rst scan- ning electron microscopy observations of these changes. Relationships within Wilsonematinae based on morpho- logical cladistics suggest a straightforward hypothesis of increasing complexity from Plectus , which could be con- sidered ancestral, to the highly ornamented condition of e.g. , Tylocephalus and Wilsonema . However, small sub- unit (SSU) rRNA sequence data are not in congruence with this morphological hypothesis, in that Tylocephalus and Wilsonema diverged before species of Plectus . We discuss the probable homologiesof various structures, and the implications of different phylogenies on character po- larity within Plectidae. 345 An improved SEM technique for preparing perineal patterns of Meloidogyne spp. and for studying host pathogen interactions of sedentary nematodes Jaime M. DOS S ANTOS UNESP/Faculdade de Ciências Agrárias e Veterinárias, Via de Acesso Prof. Paulo Donato Castellane s/n, 14884.900 Jaboticabal, SP, Brazil jmsantos@fcav.unesp.br Pieces of galled root were xed in 0.05 M potassium phosphate buffer, pH 7.4 during 5 days. Subsequently,the pieces were washed in pure buffer and partially dissected 244 Nematology</p>
<p>Poster sessions under the dissecting microscope, inside the buffer, to expose the posterior portion of females, juveniles inside the roots, giant cells or other details of the anatomical changes in the root caused by the nematodes. After that, the pieces were washed three times again in the buffer and post- xed overnight in 2% osmium tetroxide. Next, the pieces were dehydrated in ethanol, dried in critical point dryer using CO 2 , mounted onto the stubs with the structure of interest facing up using adhesive copper tape, sputtered with 30 nm of gold, observed and electron- micrographed with a scanning microscope JEOL JSM 5410, operated at 15 kV. By this technique, perineal patterns are better preserved and there is no need to cut the females in lactic acid. Juveniles inside the roots, details of the giant cells, and details of the disruption of the root tissues were documented. 346 Ultrastructure of the feeding site of Gracilacus latescens Raski, 1976 in timber bamboo roots R.N. I NSERRA 1 ; ¤ , D. A CHOR 2 , L.W. D UNCAN 2 and A. T ROCCOLI 3 1 Florida Department of Agriculture, DPI, PO Box 147100, Gainesville, FL 32614-7100, USA 2 University of Florida, CREC, 700 Experiment Station Road, Lake Alfred, FL 33850, USA 3 Istituto Nematologia Agraria, CNR, via Amendola 165/A, 70126 Bari, Italy ¤ inserrr@doacs.state..us Female Gracilacus latescens remain attached by the stylet to the surface of timber bamboo roots. Transmission electron microscope observations of the nematode feeding site showed accumulation of callose-like material enwrapping the stylet. The enwrapped stylet extends from the point of insertion in an epidermal cell wall into the lumen of two to three cells in the sclerenchyma and cortex. The callose deposit enveloping the stylet increases in thickness with each additional cell wall perforated by the stylet. Possible lignin deposit around the callose is observed in perforated sclerenchyma cells. Cross sections of the enwrapped stylet revealed the stylet tightly encased in the callose, which protects the affected cells and also anchors the stylet. A syncytium originates from the innermost cell reached by the enwrapped stylet and expands into the inner cortex and stele. Cell wall dissolution and pit elds are characteristics of the syncytium. 347 SEM observations on the coastal marine nematode Haliplectus bickneri (Chitwood, 1956) Swart et al ., 1993 G. Karssen 1 ; ¤ and A.C. van A ELST 2 1 Plant Protection Service, P.O. Box 9102, 6700 HC Wageningen, The Netherlands 2 Wageningen University, Laboratory Plant Cell Biology, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands ¤ G.Karssen@pd.agro.nl The free-living marine nematode Haliplectus bickneri (Haliplectidae: Leptolaimina) was detected in high numbers at coastal foredunes in the Netherlands and examined by eld emission electron microscopy. This proved to be very useful as most external Haliplectidae features are strongly reduced. The head region is tapering and includes: six labial-, six anterior cephalic- and four posterior cephalic papiliform sensilla; a minute stoma with 12-fold vestibulum and circular amphids. The coarsly annulated cuticle has eight longitudinal rows of body pores, between head and tail end. Annules are ornamented with ne longitudinal striae; additionally a double transverse row of punctations is present between the annules. In males a long ventral cuticular rim runs from mid-body towards four small pre-cloacal papillae, located closely together near the cloaca. The short conoid tail is provided with a nipple-like tail tip and includes a spinneret with three caudal-gland openings. The variability of some of the characters and the present position of the Haliplectidae within the Chromadorida are discussed. 348 Morphological variability of bullae in vulval cones of cysts of Heterodera glycines Ichinohe, 1952 (Nematoda: Tylenchida) evaluated with scanning electron microscopy Paola L AX 1 ; ¤ and Marcelo E. D OUCET 2 1 Laboratorio de Nematología, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, C.C. 122, 5000, Córdoba, Argentina 2 Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, C.C. 509, 5000, Córdoba, Argentina ¤ plax@arnet.com.ar The morphology of bullae in two populations of H. glycines (races 1 and 3), collected from different localities in Argentina, was studied. These cuticle protuberances were located at or under the underbridge; their size and shape were variable. Shapes varied from round Vol. 4(2), 2002 245</p>
<p>Morphology, development (336-358) to nger-like; the round bullae were of different sizes and the nger-like ones showed variable length and thickness. Few cysts had bullae of a single type; in most specimens of both populations the two different shapes were present simultaneously. The number of these structures varied from scarce to highly abundant depending on the individuals, the latter con guration being the most commonly observed. Although this character was variable, no relationship with a particular population was established. Some of the different con gurations observed would correspond to the expected pattern for other species. The considerable variability of this character requires observation of several specimens to be able to determine the tendency of these structures in the population under study. 349 Discrimination among second stage juveniles of Heterodera glycines Ichinohe, 1952 of different origin and races Paola L AX 1 ; ¤ and Marcelo E. D OUCET 2 1 Laboratorio de Nematología, Centro de Zoología Aplicada, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, C.C. 122, 5000, Córdoba, Argentina 2 Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba, C.C. 509, 5000, Córdoba, Argentina ¤ plax@arnet.com.ar Second stage juveniles of four populations of Heterodera glycines from Argentina and Brazil, belonging to races 1 and 3, were compared based on the study of their morphometrical characters. An analysis of variance showed signi cant differences among populations with respect to all the characters considered, except for the lip region height. The possible relationships among populations were evaluated through a linear discriminant analysis. Five out of the 16 characters considered resulted as the most signi cant in separating populations: body length, body diameter, pharynx length, and ratios a and b. Although the four populationsstudied showed a certain relationship in the discriminant space, it was possible to differentiate them. In the rst canonical axis, populations from Argentina and Brazil were separated; the second axis showed differences between representatives of both races considered. The results obtained show that individuals belonging to different populations and/or races of H. glycines may represent different biological entities. 350 Comparative structural, functional and expression analyses of the p -11 gene in nematodes Nikki J. M ARKS 1 ; ¤ , Christy L. M OFFETT 1 , Gunnar R. M AIR 1 , Colin F. F LEMING 2 ; 3 , David W. H ALTON 1 , Timothy G. G EARY 4 , David P. T HOMPSON 4 and Aaron G. M AULE 1 1 Parasitology Research Group, School of Biology and Biochemistry 2 Applied Plant Science, Queen’s University Belfast, Belfast BT9 7BL, UK 3 Department of Agriculture and Rural Development for Northern Ireland, Newforge Lane, Belfast BT9 5PX, UK 4 Pharmacia Animal Health, Kalamazoo, MI 49001, USA ¤ n.marks@qub.ac.uk Panagrellus redivivus has characteristics in common with Caenorhabditis elegans (size, habitat, behaviour) yet it has been assigned to a different clade. Caenorhabdi- tis elegans possesses 22 genes (designated ps ) that encode FMRFamide-related neuropeptides (FaRPs), and immunocytochemical analyses have revealed that some 50% of the nerves in both worms are FaRPergic. Us- ing chromatographic methods, two FaRPs were isolated and structurally characterised (AMRNAVLRFamide and NGAPQPFVRFamide) from P. redivivus . Functional as- says using Ascaris suum revealed that NGAPQPFVR- Famide inhibits body wall muscle and vulval function whereas AMRNALVRFamide inhibits body wall mus- cle and stimulates vulval function. Single copies of both peptides are encoded by C. elegans p -11a, and molec- ular analysis of the orthologous gene from P. redivivus revealed that AMRNAVLRFamide and NGAPQPFVR- Famide were also co-encoded on a single gene (designated pr p -1) along with the novel peptide, AAGMRNALVR- Famide. The C. elegans p -11 gene has been reported to be expressed in three paired head neurones and a tail neu- ron. In situ hybridisation analysis of pr p -1 revealed that expression was con ned to a single unpaired head neuron (RIS-like) with no staining occurring in the tail. Although p -11 and pr p -1 are orthologousneuropeptidegenes, the encoded peptides appear to ful l different roles in P. redi- vivus and C. elegans. 351 Morphological and morphometric variations of P. loosi sensu lato K.M. M OHOTTI 1 ; ¤ , M.R. S IDDIQI 2 , J. B RIDGE 3 and S.R. G OWEN 3 246 Nematology</p>
<p>Poster sessions 1 Tea Research Institute of Sri Lanka, Talawakele, 22100, Sri Lanka; 2 CABI Bioscience (UK Centre), UK; 3 University of Reading, UK; ¤ mohottik@yahoo.com Morphological and morphometric variations of 11 po- pulations of P. loosi sensu lato were examined. Exten- sive morphological and morphometric variations existed. Guatemala, Iran, Japan-Kagoshima, Japan-Shizuoka, Sri Lanka-Passara and Sri Lanka-Talawakele populations closely t the morphometrics of P. loosi sensu stricto. Scanning electron micrographs of West Africa cowpea and West Africa sorghum populations did not show sim- ilarities to P. loosi sensu stricto. The Florida popula- tion exhibited morphological similarities to both P. cof- feae sensu stricto and P. loosi sensu stricto. The Florida, Guatemala, Iran, Japan-Kagoshima, Japan-Shizuoka, Sri Lanka-Passara and Sri Lanka-Talawakele populations along with P. coffeae population were separated by prin- cipal component analysis of their female and male mor- phometrics. The populations did overlap with no obvious clusters of populations probably because of the consid- erable variability of the morphometrics. The intraspeci c variability observed in the P. loosi populations could be attributed to geography, host species and host nutrition, agronomic practices and origin of nematodes. Possible existence of distinct biological pathotypes/strains P. loosi is highlighted. The P. loosi populations were conspeci c with each other and demonstrated a ‘ P. loosi species com- plex’. 352 SEM observations of the lip region in species of the genus Discolaimus Cobb, 1913 (Dorylaimida: Qudsianematidae) with comments on their taxonomic interest Reyes P EÑA -S ANTIAGO ¤ , Baltasar T ORRES , Gracia L IÉBANAS , Joaquín A BOLAFIA and Pablo G UERRERO Departamento de Biología Animal, Vegetal y Ecología, Universidad de Jaén, Campus ‘Las Lagunillas’ s/n, 23071-Jaén, Spain ¤ rpena@ujaen.es The genus Discolaimus Cobb, 1913 is characterised by its peculiar lip region, expanded ( i.e. , markedly wider than the adjacent body) and with the oral eld more or less sunken, showing a sucker-like appearance. It is a rather homogenous genus whose species are mainly separated by morphometric features, so that their identi cation becomes a dif cult task. SEM studies of the lip region of four species ( D. major Thorne, 1939; D. agricolus Sauer & Annells, 1985; D. labiatus Peña-Santiago et al. , 2002; D. mariae Peña-Santiago et al. , 2002) collected in Andalucía Oriental (SE Iberian Peninsula) have revealed an interesting interspeci c variability affecting several features: presence/absence of perioral elevated liplets, oral eld divided in six primary radial sectors but sometimes with another six smaller interradial sectors, and outer margin divided in six, 12 or 18 lobes; moreover, both sectors and lobes may be separated by more or less deep transversal or longitudinal grooves respectively. These results make possible a new approach to the taxonomy of the genus that is brie y discussed. 353 TEM observations on early moulting of anterior body in Xiphinema dentatum (Dorylaimida: Longidoridae) Milan R ADIVOJEVIC 1 ; ¤ and August C OOMANS 2 1 Plant Protection Institute, Faculty of Agriculture, Nemanjina 6, 11080 Beograd, Yugoslavia 2 Institute of Zoology, Faculty of Sciences, RUG, K.L. Ledeganckstraat 3, 9000 Gent, Belgium ¤ milanradivoj@ptt.yu Transmission Electron Microscopy (TEM) observations on transverse sections of the anterior body in moulting Xiphinema dentatum juveniles revealed the following: anterior tissues are withdrawn from the head cuticle very early during moulting. The space in between is simultaneously lled with a liquid substance, produced by the epidermis. The epidermal cells form large chords in the body cavity, particularly laterally, and extend sheath- like epidermal outgrowths between body cuticle and somatic muscles. The moulting liquid passes via chords underneath the body cuticle. Anteriorly, the epidermal tissue assumes a tubular form during its separation from the old cuticle. At that time, it is not yet covered by new epicuticle, showing that in X. dentatum separation of the old cuticle precedes new cuticle formation. The two amphidial linings and 16 linings of papillary nerves are left in front of the tissues together with remnants of the latter. These linings encircle the old cheilostoma wall and form what was previously described as the sleeve-like membranous structure around the old cheilostoma. 354 Anomalies of genital organs in Xiphinema dentatum (Dorylaimida: Longidoridae) Milan R ADIVOJEVIC Vol. 4(2), 2002 247</p>
<p>Morphology, development (336-358) Plant Protection Institute, Faculty of Agriculture, Nemanjina 6, 11080 Beograd, Yugoslavia milanradivoj@ptt.yu During a survey of Xiphinema dentatum , numerous individuals from a single eld population in Yugoslavia were observed under dissecting microscope. Seven were found with an abnormal genital system, and these were permanently mounted and studied under light microscope. Normal males are rare, sometimes with fully developed diorchic tract, but usually with only a copulatory apparatus. Of 137 males, one is abnormal, having a normal copulatory apparatus, two abnormal testes and lacking the seminal duct. Normal females have two opposed,equally developedgenital branches, opening through a slightly anterior vulva (V D 42 : 0 § 1 : 3%). Of some 42 000 females, six were found to be abnormal. One has the genital system anatomically normal, but abnormally posterior (V D 71.0%). Two females have two normally developed systems, one system in a normal position (V D 45.9 and 43.8%, respectively), the other posterior (V D 62.1 and 65.3%, respectively). Another two females lack central parts of the system, the remaining distal parts being fused proximally. The sixth female has a normal posterior branch, while the anterior one is abnormally branching at pars dilatata uteri into two distal oviducts with ovaries, one ovary being degenerated. 355 SEM studies of the pseudolabia and cervical armature of a female Heth (Rhigonematida: Hethidae) Janet R OWE 1 ; ¤ , Rosa M ANZANILLA -L ÓPEZ 1 and David H UNT 2 1 Nematology Interactions Unit, IACR-Rothamsted, Harpenden, Herts, AL5 2JQ, UK 2 CABI Bioscience, UK Centre, Egham, Surrey, UK ¤ jarowe@bbsrc.ac.uk Heth Cobb, 1898 is an unusual genus of Rhigonematida found in the posterior gut of tropical diplopods from the American and Australasian regions. The species studied here originated in a rhinocricid diplopod from Trinidad, West Indies. Sexes are dimorphic, the female bearing a complex pair of pseudolabial plates arching over the oral aperture. The pseudolabia are subtrapezoid in shape and are attached laterally, the remaining free margins being fringed with pectinate cuticular processes. These ‘combs’ probably act as lters during feeding, restricting the size of ingested food particles. Posterior to the pseudolabia is a cervical collar bearing numerous, posteriorly directed, spines. The collar is de ected posteriorly on either side of the midlateral line to form a pair of cuticular lappets, the free margin of each lappet bearing a fringe of cuticular spines. Posterior to the lappets are two pairs of lateral spines, their bases arranged more or less in tandem. In the species studied, the transverse striae of the cervical region bear retrorse posterior margins. A number of stud- like somatic papillae are also visible. Variations in form and detail of the female cervical armature are of major diagnostic importance in speci c determination within the genus Heth . 356 Morphometry of Pratylenchus populations from coffee, banana, ornamental plant and citrus in Brazil Silvia Renata S ICILIANO -W ILCKEN 1 ; ¤ , Mário M. I NOMOTO 2 , Luiz Carlos C.B. F ERRAZ 2 and C.M.G. O LIVEIRA 3 1 FCA/UNESP, P.O. Box 237, 18603-970, Botucatu, SP, Brazil 2 ESALQ/USP, Piracicaba, SP, Brazil 3 Instituto Biológico, Campinas, SP, Brazil ¤ srenata@fca.unesp.br The morphometric variability of four Pratylenchus populations from different hosts and regions of Brazil identi ed as Pratylenchus coffeae was studied. These populations were extracted from roots of coffee, citrus (São Paulo State), Aglaonema (Rio de Janeiro State) and banana plant (Minas Gerais State) and were cultured on alfalfa callus tissues. Baermann-extracted specimens of each population from callus were killed by heat and xed with 4% formalin. Temporary slides were made and examined in light microscope. Body length (L), excretory pore to head end, stylet length, relative distance of vulva from anterior end (V%), body length/greatest body width (a), body length/distance to anterior and to junction of pharynx and intestine (b), body length/tail length (c), tail length/body width at anus (c’) were obtained. There were statistically signi cant differences in all parameters studied. 357 Cuticular diversity within the genus Ogma (Criconematidae) L.R. T IEDT 1 ; ¤ and Esther VAN DEN B ERG 2 1 Laboratory for Electron Microscopy, University of Potchefstroom for C.H.E., Potchefstroom, 2520, South Africa 248 Nematology</p>
<p>Poster sessions 2 National Collection of Nematodes, Biosystematics Division, ARC-Plant Protection Research Institute, Private Bag x134, Pretoria 0001, South Africa ¤ emslrt@puknet.puk.ac.za Females and juveniles of the genus Ogma display the most spectacular and diverse cuticular ornamentation. Some of the differences in the structure of a few species are illustrated. Cuticular structure plays an important role in the identi cation of nematode species. Until recently the cuticle of only females were studied and recorded, but it is becoming more important to take note of the fact that the cuticular structure of the different juvenile stages within a species differ from those of the female and even from each other in most species. These differences can cause problems in a population where more than one Ogma species is present because, if the diversity in species is not known, wrong identi cations can be made. It is therefore important to become familiar with and study these structures and to include their descriptions in all descriptions of species as far as is possible. The SEM is a handy tool to illustrate the cuticle variation in this genus. 358 Statistical analysis of morphometrics of Longidorus species (Nematoda: Dorylaimida) Weimin Y E and R.T. R OBBINS Cralley-Warren Center, 2601 N. Young Avenue, Fayetteville, AR 72704, USA Longidorus currently has 132 valid species based pri- marily on morphometrics. Many Longidorus species have a high degree of variability within their morphometrics which leads to considerable overlap between species and increases the potential for misidenti cation. One way Anova, Student’s t and principal components were ap- plied to compare seven species of Longidorus found in Arkansas ( L. breviannulatus , L. crassus , L. diadecturus , L. fragilis , three undescribed species) in order to screen for the most useful morphometrics in species discrimina- tion. Canonical analysis and hierarchical cluster analysis based on female average morphometric characters includ- ing body length, distance from vulva opening to head end, lip width, odontostyle length, pharynx length, body di- ameter, tail length and diameter, were used to examine the morphometric relationships and create dendrograms among 130 published Longidorus species ( L. heynsi An- drassy, 1970 and L. tardicauda Merzheevskaya,1951 with insuf cient data were not included) and 94 populations from Arkansas and other locationsby using Jump 4.0 soft- wares. Six major clusters were produced for all Longi- dorus species. Cluster analysis may lead to identi cation of unidenti ed Longidorus species. Vol. 4(2), 2002 249</p>
<p>Food webs, ecology, biodiversity (359-382) 359 List of soil nematodes from a non-tillage eld in Tsukuba, Japan, with a comment on the Maturity Index and species diversity Masaaki A RAKI ¤ and Zakaullah K HAN National Institute for Agro-Environmental Sciences, 3-1-3 Kannondai, Tsukuba, Ibaraki, 305-8604 Japan ¤ Arachis@niaes.affrc.go.jp A list of soil nematodes from a non-tillage (organic) eld established in 1981 at the National Institute for Agro- Environmental Sciences, Tsukuba, is given compared with those from a conventional (inorganic) eld and a grove nearby. The soil type of the land concerned is andosol. Barley and soybean were cultivated in a double- cropping system on the elds. The non-tillage eld was amended with manure made yearly from litter from the grove. Nematodes in 20 g soil were extracted by Baermann funnel method in October, 1999 and counted to each distinguishable taxon under compound microscope at magni cation of 100 £ . Nematode identi cation was done with specimens mounted on slides in glycerin. The total number of species detected from the non-tillage eld so far was 55, though the number of species identi ed to the species level is rather small. The number of species from the conventional eld and grove were smaller and larger than from the non-tillage eld, respectively. This tendency was the same in Maturity Indices calculated from the data, but Shannon’s H’ indices were largest in the non-tillage eld. Abundance of Monhystrella postvulvae , Prismatolaimus sp., Wilsonema othophorum , Bastiania sp., Alaimus sp. and Xiphinema sp. characterised thennon- tillage eld. In contrast, the conventional eld had greater Pratylenchus penetrans and Cephalobus sp. populations. 360 The relationship between soil type and soil texture with the spatial distribution of Heterodera glycines Felicitas A VENDAÑO ¤ , F.J. P IERCE , O. S CHABENBERGER and H. M ELAKEBERHAN Michigan State University, Department of Entomology, 243 Natural Science Building, East Lansing, MI 48824, USA ¤ avendan1@msu.edu In order to test the potential of managing soybean cyst nematode (SCN), Heterodera glycines Ichinohe site-speci cally, the spatial relationship between SCN distribution and soil texture was explored under eld conditions. Single-core soil samples were collected at planting and at harvest using a modi ed nested sampling design from two elds in Michigan. Samples were analysed for SCN cysts and soil texture. A strong correlation between cyst density and soil texture was found. Coarse soil with more than 60% sand, less than 20% silt and less than 20% clay had consistently more cysts than ner soil. As de ned by the USDA-recommended texture triangle, this composition corresponds to sandy loam, loamy sand and sand. Previous work showed SCN preference for sandy soil types, but it is important to note that only a portion of the area de ned for sandy loam in the texture triangle is favourable for SCN. Our results indicate there is a potential for site-speci c management of SCN based on soil texture (particle size) rather than soil type. 361 Structure of nematode communities in nine types of ecosystems Mirjana B RMEZ ¤ , Marija I VEZIC and Emilija R ASPUDIC University of J. J. Strossmayer in Osijek, Faculty of Agriculture in Osijek, Trg sv. Trojstva 3, 31 000 Osijek, Croatia ¤ mirjanam@suncokret.pfos.hr Nematode communities were analysed in nine ecosys- tems: winter wheat in crop rotation – standard tillage; winter wheat in crop rotation – reduced tillage; corn in monoculture; sugar beet; potato – chemical plant protec- tion; potato – integrated plant protection; alfalfa; grass- land; poplar forest. Sampling was done in 1997 and 1998, in spring and autumn, to the depth of 15-20 cm. Nematode communities were analysed to genus level. Greatest num- ber of nematodes and number of genera were 2843 ne- matodes/100 g of soil in alfalfa treatment, and 30 genera in poplar treatment. Lowest was in row crops (216 and 12 genera in sugar beet). Analyses of nematode trophic structure showed greatest abundance of bacterial feeders and plant parasitic nematodes in all treatments, and lowest abundance of omnivorous nematodes and predators. The greatest abundance of predators was determined in poplar forest. Positive correlation between quantity of humus and total number of nematodes was determined but a nega- tive correlation between amount of K 2 O and number of genera. Statistically very signi cant differences occurred between treatments in analysing MI, PPI and PPI/MI and showed the most disturbed nematode communities in row crops, the less disturbed in poplar forest, grassland and al- falfa; and intermediate group was wheat with reduced and standard tillage. 250 Nematology</p>
<p>Poster sessions 362 Effects of soil pH on Heterodera glycines reproduction and soybean chlorosis Senyu C HEN and Daniel M ILLER Southern Research and Outreach Center, University of Minnesota, 35838 120 th Street, Waseca, MN 56093, USA Soybean cyst nematode, Heterodera glycines , is a destructive pest on soybean in Minnesota, a state in the North Central region in the United States, where soybean is a major crop. The objective of this study was to determine the effect of soil pH on H. glycines reproduction and iron-de ciency chlorosis of soybean in elds. A survey was conducted in a 20 acre area in a commercial soybean eld in Waseca, Minnesota, to monitor soil pH, density of H. glycines , and severity of iron-de ciency chlorosis of soybean in 2001. Positive correlation between either two of the three variables was signi cant. Glasshouse studies con rmed that H. glycines reproduction on susceptible soybean increased with increasing soil pH from 5 to 8. The results suggest that H. glycines may increase severity of iron-de ciency of soybean at higher soil pH in Minnesota elds. 363 Relationships between nematode and microbial communities and carbon transfers in grassland soils Roger C OOK 1 ; ¤ , Lorna D AWSON 2 , Alan G ANGE 3 , Sue G RAYSTON 2 , Tony M IZEN 1 , Phil M URRAY 4 , Amy T REONIS 2 and Nick O STLE 5 1 Institute of Grassland and Environmental Research, Aberystwyth Research Station, Aberystwyth SY23 3EB, Wales, UK 2 Macaulay Institute, Craigiebuckler, Aberdeen, Scotland, UK 3 Royal Holloway University of London, Egham, Surrey, UK 4 Institute of Grassland and Environmental Research, North Wyke Research Station, Devon, UK 5 Centre for Ecology and Hydrology, Merlewood Research Station, Grange-Over-Sands, Cumbria, UK ¤ roger.cook@bbsrc.ac.uk At an upland eld site, plots of an established Festuca – Agrostis pasture and of a newly sown monoculture of Lolium perenne have been treated for 3 years with nitrogen and lime or with pesticide (chlorpyrifos). These treatments were designed to produce contrasting degrees of diversity in communities of soil animals and microbes as part of our research on the relationships between grassland management practice and the diversity of biological communities in soil. Nematode communities have been described by trophic composition and by ecological indices based on proportions of ve groups on the coloniser-persister scale. These data are analysed in relation to variations in root growth and microbial community structure and activity over 3 years. In additional plots, the 13 C xed by photosynthesis of a 24 h pulse of 13 CO 2 applied to the herbage, was detected in nematodes extracted from underlying soil at 8, 22, 48 and 69 days after the pulse. There was more 13 C in nematodes from untreated controls than from limed plots. These differences are consistent with a greater carbon ux in soils treated with lime, but could not be related to differences between the nematode communities. 364 A new nematode genus (Rhabditida: Panagrolaimidae) from pitcher plants Paul D E L EY 1 ; ¤ , Wim B ERT 2 , Andy V IERSTRAETE 2 , Irma T. D E L EY 1 , Rita V AN D RIESSCHE 2 and Hendrik S EGERS 2 1 Department of Nematology, University of California – Riverside, CA 92521, USA 2 Vakgroep Biologie, Universiteit Gent, Ledeganckstraat 35, B-9000 Gent, Belgium ¤ pdeley@citrus.ucr.edu Measurements, line drawings and scanning electromicro- graphs are provided of a new nematode species and genus, isolated from pitcher uid of Nepenthes sp. from Thai- land. The new genus differs from all known nematodes in having two opposing and offset spermathecal pouches at the junction of oviduct and uterus. It also differs from all known Rhabditida in having four cephalic setae instead of papillae. Phylogenetic analysis of small subunit rDNA sequence data robustly places the new genus within Pana- grolaimidae, as sister taxon to Panagrellus . These unusual nematodes resemble Panagrellus in e.g ., body size (1.8- 2.5 mm in females, 1.3-1.8 in males) and in the monodel- phic, prodelphic female reproductive system with thick- ened vaginal walls and prominent postvulval sac. How- ever, they differ from Panagrellus in the characters men- tioned above, in the presence of liplets around the mouth opening, in their comparatively longer stegostom, and in the shape of the male spicules. Because of its aberrant characters, inclusion of this new genus in Panagrolaimi- dae will entail changes to the family diagnosis. 365 Ecophysiologicalstudies on pine wilt disease occurring in coastal dunes Kazuyoshi F UTAI 1 ; ¤ , Shigenobu T AMAI 2 , Vol. 4(2), 2002 251</p>
<p>Food webs, ecology, biodiversity (359-382) Norikazu Y AMANAKA 2 and Fukuju Y AMAMOTO 3 1 Laboratory of Environmental Mycoscience, Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan 2 Laboratory of Revegetation and Grassland Development, Tottori University Arid Land Research Center, 1390, Hamasaka, Tottori 680-0001, Japan 3 Faculty of Agriculture, Tottori University, 4-101 Koyama-cho Minami, Tottori, 680-8553, Japan ¤ futai@kais.kyoto-u.ac.jp The spreading manner of pine wilt disease has been compared between two 20 £ 20 m experimental plots established in Japanese black pine forest distributed over coastal dunes in Tottori University Arid Land Research Center. One of the plots was fertilised every year since 1996, and the other one remained with no treatment and served as a control. The number of pine trees killed by pine wilt disease was far more in the fertilised plot than in the control one, suggesting that the fertilisation might have promoted the death of pine trees by pine wilt disease. To reveal the reason why the fertilisation promoted the pine wilt disease, mycorrhizal relationship has been examined as a possible cue to explain the difference. Fertilisation might suppress mycorrhizal synthesis which has been regarded to work as absorbing organ for pine trees especially when under water stress. Diversity and constitutions of mycorrhizae formed on young pine seedlings were compared between the two plots, and among three groups of pine seedlings with different watering regimes. We conclude that mycorrhizal relations play an important role to make pine trees survive the epidemic wilt disease. 366 Effect of soil pH on Heterodera glycines population density in Brazil Antonio G ARCIA 1 ; ¤ , Waldir Pereira D IAS 1 , João Flávio Veloso S ILVA 1 , Roberto Kazuhiko Z ITO 2 and Angela Francoise C ARVALHO S ANTOS 3 1 Embrapa Soja, CP 231, 86001-970, Londrina-PR, Brazil 2 EPAMIG, Afonso Rato, 1301, 38001-970, Uberaba-MG, Brazil 3 UNIFIL, Juscelino Kubtscheck, 1626, 86020-918, Londrina-PR, Brazil ¤ garcia@cnpso.embrapa.br Previous observations in growers’ elds infested with the soybean cyst nematode (SCN), Heterodera glycines , suggested that SCN populations remained higher for long periods in soils with high pH. Therefore, experiments were conducted in three regions from 1995 to 2000, comparing two pH levels, under two crop rotation systems using corn; one (pH5 to 5.5 in CaCl 2 / representing the recommended pH range, and another (6 to 6.5) representing a high pH level. In all experiments there was a trend of higher SCN population density in plots with higher soil pH. Under these conditions, 1 year rotation with corn reduced the SCN population, but its incidence was still higher in plots with higher soil pH. 367 Edaphic microfauna in woody crops from Mediterranean environments Avelino G ARCIA -Á LVAREZ 1 ; ¤ , Carlos S IMÓN 2 , Susana C. A RCOS 1 , María A RIAS 1 and Victor E SPANTALEÓN 2 1 Dpto Agroecología, CCMA, CSIC, Serrano 115 dpdo, 28006 Madrid, Spain 2 Dpto Zoología, Univ. Autónoma, Cantoblanco, Madrid, Spain ¤ aga@ccma.csic.es Microfauna associated with several vineyard and olive crops grown in a continental Mediterranean climate under various soil management systems on the Spanish Central plateau were studied. Nematode trophic groups and microarthropod populations in plots under different cropping systems (non-tillage, traditional tillage, covers with clover, weeds or vetch) were studied in comparison with two controls (soil from an abandoned cereal crop and a hedge of wild vegetation). Plant-parasitic and bacteria-feeder nematodes had the highest populations in the hedge control and in plots with clover cover, while their populations were lower under non-tillage. Predators were abundant in grape: under traditional management, under a covering of runners and in the control group. However, fewer predators were found in non-tillage plots, where omnivorous predators abound, in olive with clover cover and in the control group with natural vegetation. Collembola had a higher population in all alternatives in plots with clover cover and control groups. Acari were frequent in vineyards, except in weed-covered and non- tilled plots and along the edge, appearing in weed-covered olive and the control group. Coleoptera appeared in all but non-tilled olive plots while Diptera were in vineyards, except those under tillage, and the control group, where only Thysanoptera were present. 252 Nematology</p>
<p>Poster sessions 368 Diversity of soil nematodes in an alpine dwarf-shrub heath in Austria: rst results of a 2 year study Michael H OSCHITZ ¤ and Pamela Z OLDA Institute of Ecology and Conservation Biology, Althanstraße 14, A-1090 Vienna, Austria ¤ mischahoschitz@hotmail.com The soil nematode community was investigated in an alpine dwarf shrub heath in the Central Alps (1930 m) near Obergurgl, Austria. The vegetation on the acidic soil consisted mainly of Vaccinium gaultherioides , V. myrtillus and Rhododendron ferrugineum . The aim of the study was rstly to investigate the nematode biodiversity of alpine environments. Secondly, it was designed to serve as a basis for investigations on the use of nematode communities as an indicator for the global climate change. A total of 216 soil samples was taken in July, August and September 2001. All nematodes extracted from bulk samples were identi ed and counted. Nematodes of all ve feeding groups were encountered. A list of species, species abundance, diversity indices and the maturity index are presented. The nematode community is apparently typical for alpine regions and the most dominant genus was Rotylenchus sp. (Tylenchidae). Further plant-feeding families were Pratylenchidae and Paratylenchidae. Within the predators, Mononchidae and Anatonchidae were encountered and the bacterial feeders were represented by the Prismatolaimidae, Plectidae, Cephalobidae and Teratocephalidae. Genera of the omnivorous families Dorylaimidae and Aporcelaimidae were identi ed, along with genera of the fungivorous Aphelenchidae, Aphelenchoididaeand Nordiidae. 369 Current uncertainties in the estimation of soil nematode diversity and its use in soil quality monitoring Juan José I BÁÑEZ ¤ , Avelino G ARCÍA -Á LVAREZ and María A RIAS Dpto de Agroecología, CCMA, CSIC, Serrano 115 dpdo, 28006 Madrid, Spain ¤ jjibañez@ccma.csic.es Estimation of soil biodiversity and monitoring of soil quality are two of the major priorities of the international environmental agenda, although their quanti cation is not free from uncertainties. This contribution analyses these uncertainties. In an Acrisol under a continental Mediterranean climate, the study of nematofauna took the following issues into account: i ) land use, ii ) various soil horizons, iii ) seasons, and iv ) extracting methods. Results show that an estimation of the taxonomic biodiversity and individualabundance patterns is not possible, without taking all the above-mentioned items into account. Different extracting methods show distinct scenarios, as well as respect for seasons and soil depth. Sampling the upper 15 cm of the A horizon involved a great abundance of soil individuals, biomass and biodiversity. It is also demonstrated that in some instances the B horizon (not usually sampled for soil biodiversity and soil monitoring studies) has more individuals and taxonomic diversity than the A horizon. Thus, from the data obtained, it seems that both the theoretical assumptions and the standard techniques currently used for soil biodiversity and soil- monitoring studies do not show the complexity of soil nematofauna. Therefore, we need to improve present methods to develop more relevant research on these topics. 370 Nematode abundance, diversity and trophic structure in relation to spatial heterogeneity of a natural fen Krassimira I LIEVA -M AKULEC Institute of Ecology, Polish Academy of Sciences, Dziekanow Lesny, 05-092 Lomianki, Poland krassi@poczta.onet.pl The abundance, diversity, and trophic structure of nematode communities of a natural tall-sedge fen in Poland were studied. The sedge association was of a tufty structure due to the dominance of Carex paradoxa . Soil samples were taken in the spring (May) and in the summer (July) within and outside of the sedge tussocks. It was found that nematode communities were more abundant and more diverse within than outside of the tussocks and the differences were more pronounced in the spring than in the summer. Both habitats differed also in nematode trophic structure and in the relative importance of the trophic groups. No omnivorous and predatory nematodes were found in the soil between tussocks on the spring sampling. Bacterial-feeding nematodes predominated in the two habitats but, while within the tussocks, on both sampling dates they contributed to about 60% of the total nematode numbers in the soil between tussocks, bacterial- feeding nematodes constituted 94 and 73% in spring and summer, respectively. The variation of nematode community parameters in such a short distance was Vol. 4(2), 2002 253</p>
<p>Food webs, ecology, biodiversity (359-382) explained by the differences in some soil characteristics of the two studied habitats. 371 Phylogenetic analysis of the phoretic association between Bursaphelenchus conicaudatus (Nematoda: Aphelenchoididae) and Psacothea hilaris (Coleoptera: Cerambycidae) Natsumi K ANZAKI ¤ and Kazuyoshi F UTAI Laboratory of Environmental Mycoscience, Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan ¤ kanzakii@kais.kyoto-u.ac.jp The phoretic relationship between the nematode Bursa- phelenchus conicaudatus and the yellow-spotted longi- corn beetle, Psacothea hilaris , collected at various dis- tricts in Japan were investigated. All ten subspecies of the beetle examined were infected with the nematodes at a high proportion suggesting the universality of this phoretic association. Molecular analysis based on the par- tial base sequence of cytochrome oxidase subunit I in the mitochondrial DNA revealed that the phylogenetic rela- tionship among ten subspecies of the beetle was similar to that among associated nematode isolates obtained from each beetle subspecies. Intraspeci c vector replacements were supposed to occur in the isolates of B. conicaudatus on two islands. The phoretic association between the ne- matodes and the beetles was assumed to be on the way from non-speci c facultative commensalism to speci c obligative commensalism. 372 In uence of diverse agricultural systems on the population dynamics of free-living, plant-parasitic and entomopathogenic nematodes Stephen R. K OENNING ¤ and Mary E. B ARBERCHECK Campus Box 7616, Department of Plant Pathology, NC 27695-7616, USA; Campus Box 7634, Department of Entomology, North Carolina State University, Raleigh, NC 27695-7634, USA ¤ srkpp@unity.ncsu.edu The population dynamics and densities of soil-inhabiting nematodes were measured in different agricultural systems at the Center for Environmental Farming systems near Goldsboro, NC, USA. Systems studied included old- eld succession, forestry, integrated crop/animal, organic, and cotton in conventional vs no-till production. Numbers of omnivorous and predacious nematodes were greatest in forestry, successional and organic systems in July and September compared to conventional cropping systems ( P D 0 : 01 / . The population densities of fungivorous and bactivorous nematodes were greater in organic systems compared to other systems at the July sampling, but not in September ( P D 0 : 01 / . Temporal variation in populationmaximum may in uence conclusions about the relationships of trophic groups to one another. The use of organic amendments to supply nutrients in the organic system may be responsible for high numbers of free-living nematodes in these treatments. Cotton in no-till production had greater numbers of bacterial feeding nematodes than conventional tillage ( P D 0 : 10 / . The presence of various species of plant-parasitic nematodes was related to the crop grown, and was little in uenced by tillage system. The entomopathogenic nematodes Steinernema glaseri , Steinernema carcocapsae and Heterorhabditis bacteriophora were detected in all treatments. Highest numbers of entomopathogenic nematodes were detected in the succession and forestry treatments. 373 An essay of detection of zoogeographic units of the territory in base to nematode fauna distribution: the case of a protected area in SE Iberian Peninsula Gracia L IÉBANAS 1 ; ¤ , Reyes P EÑA -S ANTIAGO 1 , Raimundo R EAL 2 , Ana Luz M ÁRQUEZ 2 , Juan Manuel M ARTÍN -G ARCÍA 3 , Joaquín A BOLAFIA 1 and Pablo G UERRERO 1 1 Departamento de Biología Animal, Vegetal y Ecología, Universidad de Jaén, Campus ‘Las Lagunillas’ s/n, 23071-Jaén, Spain 2 Departamento de Biología Animal, Facultad de Ciencias, Universiad de Málaga. 29071-Málaga, Spain 3 Departamento de Geología, Universidad de Jaén, Campus ‘Las Lagunillas’ s/n, 23071-Jaén, Spain ¤ gtorres@ujaen.es The identi cation of biotic regions, i.e ., series of operational geographic units (OGU) that share a similar fauna, leading to the division of the territory into operational zoogeographic units (OZU), was one of the objectives of a nematological project addressing the taxonomy and distribution of dorylaimid and mononchid nematode fauna of the Sierra Mágina Natural Park (SE Iberian Peninsula). Sixty OGU of the UTM (Universal Tranversal Mercator) 2 £ 2 km square grid were classi ed in base to the presence/absence of 138 nematode species using a quantitative analysis protocol. The results 254 Nematology</p>
<p>Poster sessions obtained suggest that the studied area may be divided into seven biotic (zoogeographic) regions with their respective biotic boundaries. The biotic regions have been environmentally characterised, with altitude, slope, and sand and clay contents the main factors in uencing the division. The analysis also produced a faunistic characterisation of the biotic regions. These results, which represent a new approach to the study of nematode distribution, are discussed. 374 Nematode community and trophic structure along a sand dune succession Roy N EILSON ¤ , John W. W ALL and Keith R. S KENE Plant and Pathogen Co-Evolution Programme, Scottish Crop Research Institute, Dundee, DD2 5DA, Scotland, UK; School of Life Sciences, University of Dundee, Dundee, DD2 1HN, Scotland, UK ¤ roy.neilson@scri.sari.ac.uk Changes in below-ground nematode communities, in terms of abundance, diversity, trophic structure, sex bias and adult : juvenile ratio were related to edaphic fac- tors from sample sites representing differing successional stages. Nematode abundance increased along a 1 km tran- sect of increasing succession, from sandy beach through active dune systems to mature dunes. As the succession progressed, the adult nematode sex ratio changed from male biased to highly female biased. Consequently, the adult : juvenile ratio decreased as the nematode com- munity became more female dominated. An assessment of nematode diversity using both univariate and multi- variate analysis produced contradictory results. Univari- ate indices yielded inconsistent results with different in- dices suggesting lower diversity at different successional stages. Multivariate analysis clearly separated the beach and dune heath samples from the other samples and each other and, to a lesser extent, separated the fore dune sam- ples from the grey and yellow dune. Omnivorous nema- todes represented the largest trophic component of the ne- matode community in all successional stages of the terres- trial sites. A trend was apparent of increasing numbers of omnivorous nematodes along the succession in relation to increasing organic matter and/or litter accumulation. 375 Analysis of nematofauna in some coastal dune ecosystems of Sicily Lara O RSELLI ¤ and Maria Teresa V INCIGUERRA Dipartimento di Biologia Animale, via Androne 81, 95124 Catania, Italy ¤ lorselli@unict.it A survey of nematodes of some coastal dune ecosystems in Sicily was carried out both from a faunistic and an ecological point of view. The species composition was very peculiar, with many new species, many taxa typical of dunes or rare, and some others typical of coastal marine and brackish environments. The ecological analysis was conducted more deeply in two nature reserve sites, namely Vendicari and Irminio river-mouth, with different environmental characteristics. Shannon diversity index, species richness, evenness, maturity index, frequencies of c-p categories and of trophic groups were calculated at each station. The results were compared with those from some other coastal sites with a different degree of environmental disturbance. Both biodiversity and maturity were higher in the stations where dunes were better preserved, but the differences among the sites were not as high as one would expect, probably because dune nematodes are adapted to survive in such highly changing environments. 376 Restoration of soil nematode fauna (dorylaims and mononchs) in the Guadiamar River basin (SW Iberian Peninsula) 3 years after a mining accident Reyes P EÑA -S ANTIAGO 1 ; ¤ , Domingo J IMÉNEZ -G UIRADO 2 , Gracia L IÉBANAS 1 , Raquel M URILLO 2 , Joaquín A BOLAFIA 1 and Pablo G UERRERO 2 1 Departamento de Biología Animal, Vegetal y Ecología, Universidad de Jaén, Campus ‘Las Lagunillas’ s/n, 23071-Jaén, Spain 2 Departamento de Biología Animal, Universidad de Córdoba, Campus de Rabanales, Edi cio C-1, 14071 Córdoba, Spain ¤ rpena@ujaen.es As a consequence of the mining accident which occurred at the Guadiamar River basin (SW Iberian Peninsula) in April 1998, part of the river banks were covered with toxic mud containing heavy metals, and a research project focused on the faunistic characterisation of the area and control of the recolonisation process was undertaken. Nematode fauna, particularly dorylaims and mononchs, was included in the study. A few well-conserved and non-polluted natural areas (biocentres), and a series of experimental plots located in the river banks, have been surveyed over two seasons (spring and autumn) during 2 years (2000 and 2001). One hundred and twenty seven Vol. 4(2), 2002 255</p>
<p>Food webs, ecology, biodiversity (359-382) soil samples were collected, but only 99 have been studied at present. More than 100 species constitute the fauna of the region, indicating a remarkable faunistic potential of this geographical area. Concerning the recolonisation process, two distribution patterns, one spatial and another temporal, have been detected and are also discussed. 377 Soil nematode community as a valuable bioindicator of soil ecosystem recovery after mining spillage in southern Spain S. S ÁNCHEZ 1 ; 2 , J.A. C AMARGO 1 and A. N AVAS 2 1 Departamento Interuniversitario de Ecología, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain 2 Museo Nacional de Ciencias Naturales, C.S.I.C., Madrid, Spain In April 1998, an amount of about 5hm 3 of toxic sludge, with high concentrations of heavy metals, was released along the Guadiamar river system as a consequence of the tragic Aznalcollar accident in southern Spain. In order to evaluate the environmental impact produced by the heavy metal pollution on soil health conditions, we carried out eld and laboratory studies. Ten control and 27 polluted soil samples were taken along the Guadiamar riverside in three sampling periods (June 2000, December 2000 and June 2001). For each soil sample, values of diversity and trophic indices were calculated, and the concentration of heavy metals (Pb, Zn, Ni and Cu) was analysed. Soil nematodes were identi ed, at least to the genus taxonomic level. In addition, short-term toxicity bioassays were conducted in triplicate using adults of Aphelenchus avenae and Cephalobus persignis collected at the control area. Results from eld studies showed that concentrations of heavy metals were signi cantly higher at polluted sites than at control sites. Conversely, values of biological indices were signi cantly much lower at polluted sites. Results from short-term toxicity bioassays revealed that Pb and Cu are mainly responsible for the observed environmental impact on the soil nematode community. In spite of the fact that concentrations of heavy metals remained similar among sampling periods, values of biological indices exhibited a clear tendency to increase since the mining spillage. 378 Nematodes as indicators of waste water treatment Carmen S ANTOS L OBATÓN 1 ; ¤ , Eva T RUJILLO M ENA 1 and Miriam C ASAUS A LVAREZ 1 1 Laboratorio de Nematología. Dpto de Fisiología y Zoología, Avda, Reina Mercedes 6, 41012 Sevilla, Spain ¤ csantosl@us.es In this paper we present the results of a study carried out on 28 waste waters of Andalucía (Spain) in order to assess the presence of nematodes in the environs of the treatment process with special attention to sludge sam- ples that can constitute a suitable environment for devel- opment of this organisms. Nematodes were present in all the waste water and 21 species belonging to 21 genera were identi ed. These species are Alloionema appendicu- lata , Eudorylaimus intermedius , Brevibucca saprophaga , Cervidellus cervus , Pelodera serrata , Cruznema triparti- tum , Diploscapter coronatus , Fictor similis , Mesorhab- ditis spinula , Neodiplogaster pissodis , Panagrobelus in- cisus , Paroigolaimella coprophaga , Pelloditis friderici , Pelodera teres , Protorhabditis liformis , Rhabditis mau- pasi , Rabditis producta , Rhabditophanes schnederi , Ty- locephalus auriculatus , Anguillula aceti , Tylopharinx phoetida and Xiphinema pachtaicum . Species were grouped according to their feeding habits and their com- munity composition were studied. The results obtained provide new information on the occurrence of populations and role of these organisms as indicators. 379 Dispersal ability of Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae) and inhibition by Pinus densi ora branches Katsumi T OGASHI ¤ , Koji M ATSUNAGA , Yoh A RAKAWA and Naoto M IYAMOTO Faculty of Integrated Arts and Sciences, Hiroshima University, Kagamiyama 1-7-1, Higashi-Hiroshima 739-8521, Japan ¤ togashi@hiroshima-u.ac.jp To determine the degree of inhibition against the nematode dispersal by live Pinus densi ora trees, four Bursaphelenchusxylophilus isolates of different virulence and one B. mucronus isolate were inoculated separately on the upper cut ends of 2.5 and 5.0 cm long living branch sections. An increase in live section length induced an 80% decrease in the number of passing nematodes irrespective of isolates. That value was higher than 45.2% for more susceptible pine species and lower than 100% for a resistant, interspeci c hybrid. Further, to determine the among-isolate difference in vulnerability to inhibitory effect of the live trees on nematode dispersal, the ve 256 Nematology</p>
<p>Poster sessions isolates were inoculated on the upper cut ends of boiled and live branch sections 5 cm long. The vulnerability to inhibitory effect of the live trees differed among isolates. Two experiments showed that virulence had no relation to intrinsic and realised dispersal rates in B. xylophilus . Analysis of spatial distribution of B. xylophilus 24 h after inoculation on 25 cm long branch sections showed the random dispersal with diffusion coef cient of 40.73 and 109.4 cm 2 /day for live and boiled branches, respectively. 380 Rhizodeposition and soil microbial communities in clover plants infected with the clover cyst nematode, Heterodera trifolii Amy T REONIS 1 ; ¤ , Roger C OOK 2 , Lorna D AWSON 3 , Sue G RAYSTON 3 , Karen L OWES 2 , Tony M IZEN 2 , Brian O RD 3 , Ruth P RIMROSE 3 , Eileen R EID 3 and Jasmine R OSS 3 1 Department of Biology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA 2 Institute of Grassland and Environmental Research, Plas Gogerddan, Aberystwyth SY23 3EB, UK 3 The Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH, UK ¤ atreonis@creighton.edu Below ground herbivory can alter the distribution of plant-derived soil organic matter and may impact on soil microbial diversity and functioning. Invertebrate root feeding organisms include the larval stages of many insects as well as ecto- and endoparasitic nematodes. The process of root herbivory is likely to have signi cant impacts on soil microbes that rely on root-derived carbon as an energy source. Heterodera trifolii , the clover cyst nematode, is a sedentary endoparasite of clover roots. Our objective was to determine how plant growth and rhizosphere carbon availability change when roots are infected by parasitic nematodes and how changes in the quantity and quality of rhizosphere carbon in uence the structure and function of the soil microbial community. Clover was grown in microcosms in sand with or without H. trifolii . Rhizodeposits were washed from the sand periodically for chemical analysis. These solutions also were applied to plant-free grassland soil to evaluate the response of the microbial communities. Changes in rhizosphere chemistry were linked to microbial responses and will be discussed. The results contribute to understanding the indirect effects of plant-parasitic nematodes on the rhizosphere environment and microbial diversity and function in grasslands. 381 Ecology of plant-parasitic nematodes, their host plants and antagonists in European coastal sand dunes: training opportunity for ecologists and agricultural biocontrol researchers ( EcoTrain ) Wim H. VAN DER P UTTEN 1 ; ¤ , B.R. K ERRY 2 , K.G. D AVIES 2 , R. C OOK 3 , M. M OENS 4 , M. F ARGETTE 5 , T. M ATEILLE 5 , J. B AKKER 6 and H. F REITAS 7 1 Netherlands Institute of Ecology (NIOO-CTO), P.O. Box 40, 6666 ZG Heteren, The Netherlands 2 Rothamsted Experimental Station (IACR), UK 3 Institute of Grassland and Environmental Research (IGER), UK 4 Centrum voor Landbouwkundig Onderzoek (CLO), Belgium 5 Institut de Recherche pour le Developpement (IRD-CBGP), France 6 Wageningen University (WU), The Netherlands 7 Instituto do Mar (IMAR), Portugal ¤ putten@cto.nioo.knaw.nl EcoTrain aims to examine the regulation of plant-parasitic nematodes in natural ecosystems, which processes contribute most to nematode control, and how predictable they are. The concepts and technology resulting from this study will encourage research into multitrophic interactions in natural soils, which seriously lags behind research on aboveground multitrophic interactions. Basic insights resulting from EcoTrain will also bene t research on the biological control of nematodes in production systems, which is currently based mainly on trial and error. Speci c objectives of EcoTrain are: i/ to examine and compare potential mechanisms that control population densities of plant parasitic nematodes in nature, ii ) to bridge and stimulate scienti c co-operation between phytopathologists working in production systems and ecologists working in natural environments, iii ) to set up a trans-European network of agronomists and ecologists with a mutual interest in soil phytopathology and iv ) to stimulate biological control of plant-parasitic nematodes in agriculture by learning how this works in nature. EcoTrain will use coastal sand dunes of Europe as a natural model system. These dunes provide one of the best case studies on interactions of natural plants and their parasitic nematodes. The natural occurrence of dominant dune grasses in monospeci c stands and the heavy soil disturbance makes sand dunes a good model for agricultural production systems. Website address: http://www.nioo.knaw.nl/projects/ecotrain/index.htm. Vol. 4(2), 2002 257</p>
<p>Food webs, ecology, biodiversity (359-382) 382 Seasonal change of Caenorhabditis japonica on the shield bug, Parastrachia japonensis Toyoshi Y OSHIGA ¤ , Yuji I SHIKAWA , Mantaro H IRONAKA and Eizo K ONDO Laboratory of Nematology, Department of Applied Biological Sciences, Saga University, Saga 840-8502, Japan ¤ tyoshiga@cc.saga-u.ac.jp Caenorhabditis japonica , a species closely related to the C. elegans group, is associated with the shield bug, Paras- trachia japonensis showing provisioning behaviour. To elucidate the ecology of C. japonica , the nematode po- pulation on the bug was investigated at a deciduous for- est of Hinokuma Mountain, Saga, Japan from March 2001 to February 2002. During the period of reproduc- tive diapause of the bug, until early May, dauer juveniles of C. japonica were exclusively found as clusters under the scutellum of almost all female bugs investigated while those were rare on male bugs. During the mating, oviposition and egg guarding periods of the bug, from early May to June, nematode population on the bug remained nearly unchanged. When the rst stage nymphs hatched in late June, the nematode became undetectable from female bugs. Dauer juveniles appeared on the bug at the second stage and were always detectable on nymphs of both sexes until the bugs became adults in late July. Thereafter the number of dauer juveniles on female bugs gradually increased while those on male bugs decreased and became almost undetectable in February of the next year. Ecological relationships of C. japonica to the life cycle of P. japonensis will be discussed. 258 Nematology</p>
<p>Poster sessions 383 Survey of the pine wilt nematode and its vector insects in the autonomous community of Galicia, northwestern Spain Adela A BELLEIRA 1 ; ¤ , Miguel E SCUER 2 , J. Pedro M ANSILLA 1 , María A RIAS 2 and Antonio B ELLO 2 1 Estación Fitopatológica ’Do Areeiro’, Subida a la Robleda s/n, 36153 Pontevedra, Spain 2 Dpto Agroecología, CCMA, CSIC. Serrano 115 dpdo, 28006 Madrid, Spain ¤ aabelleira@efa-dip.org Surveys have been carried out to detect Bursaphelenchus spp. in the Galician Community because the pine wilt nematode B. xylophilus was reported in Portugal. Forest areas in this region represent almost 12% of the forest areas in Spain, with conifers at 7% and Pinus pinaster at over 25%. Besides, Galicia is one of the main routes in Spain for imported timber. Several samplings were taken between 1999-2001. The rst time, 1249 samples were collected from pine trees with or without symptoms, taken every 5 km 2 . The other samplings were gathered according to European Community rules, 2179 samples being analysed from pine trees, sawmills and imported wood. Species were identi ed mainly on the basis of morphometric characteristics and, when necessary, by PCR-RFLP techniques. Four species of Bursaphelenchus were found: B. eggersi in four samples from P. pinaster and P. radiata with symptoms of decline, B. sexdentati and B . cf . eremus , once each, associated with a declining pine tree close to sawmills, and B. mucronatus at four sawmills on P. pinaster , imported timber from the Ukraine and France. The vector insect for B. xylophilus , Monochamus galloprovincialis , was also collected on imported wood from sawmills. 384 Population dynamics of the potato cyst nematode ( Globodera sp.) in two potato varieties cultivated in the Balearic Islands Raquel A LONSO 1 ; ¤ , Ana A LEMANY 2 and Maria F É A NDRÉS 1 1 Department of Biology, University of the Balearic Islands, Cra. de Valldemossa km. 7,5. 07071-Palma of Mallorca, Spain 2 Centro de Ciencias Medioambientales, CSIC, Madrid, Spain ¤ raqxmixmail.com The biology and population dynamics of the potato cyst nematode (PCN) have been studied in two commercial potato varieties cultivated in Sa Pobla-Muro (Balearic Islands, Spain) in order to arrive at locally relevant solutions for their appropriate management. The Maris Peer short cycle potato variety is usually planted in November and harvesting starts in February, while cv. Marfona, a large cycle potato variety, is usually planted in January and harvesting starts in May. In both, the highest level of second-stage juvenile hatching takes place 2 months after planting and the highest level of root invasion occurs a month later, with the plant showing damage due to the nematode infection from this time on. In cv. Maris Peer, nematodes cannot complete the whole cycle due to the early harvest, while the nematode cycle is shorter in cv. Marfona because of the warmer temperatures, thus giving a greater rate of reproduction. In the same way, the effect of PCN life cycle on host-plant development and crop loss has been studied to know the PCN population densities in which most plants can tolerate invasion and damage, without it adversely affecting potato yield. 385 Survey of plant-parasitic nematode genera in Al-Qassim area, Saudi Arabia S. A L -R EHIAYANI ¤ and A. F ARAHAT College of Agriculture & Veterinary Medicine, King Saud University, AL-Qassim Branch, P.O. Box 1482, Saudi Arabia alreh@yahoo.com An extensive survey was carried out in Buriedah City and the ten governorates of Al-Qassim area Saudi Ara- bia. The study was conducted to examine and evalu- ate the distribution of plant-parasitic nematode genera, the degree of nematode infestation and plant nema- tode associations. Twenty one nematode genera were found in this survey: Meloidogyne, Helicotylenchus, Tylenchorhynchus, Pratylenchus, Heterodera, Tylenchu- lus, Rotylenchulus, Hemicriconemoides, Macropostho- nia, Trichodorus, Paratrichodorus, Paratylenchus, Tro- phonema, Hoplolaimus, Xiphinema, Longidorus, Hemi- cycliophora, Aphelenchoides, Ditylenchus, Aphelenchus and Tylenchus . The most common genera in almost all governorates are Meloidogyne, Helicotylenchus , Tylen- chorhynchus and Pratylenchus . The frequency of ne- matode occurrence and the population densities varied greatly between governorates. Meloidogyne and Helicoty- lenchus dominated on fruit trees, while Tylenchorhynchus and Pratylenchus dominated on eld crops. The popula- tion densities of Meloidogyne were higher on vegetable crops, especially tomato and eggplant. Unayzah, Al- Mezneb, Al-Asyah governorates and the city of Buriedah Vol. 4(2), 2002 259</p>
<p>Distribution, population dynamics (383-443) are infested with the highest nematode genera. The great- est number of nematode genera is associated with date palm trees. Trophonema is recorded in this study for the rst time in Saudi Arabia and Rotylenchulus for the rst time in Al-Qassim area. 386 The cereal nematode , Heterodera avenae , in Al-Qassim area, Saudi Arabia S. A L -R EHIAYANI P.O. Box 1482, College of Agriculture & Veterinary Medicine, King Saud University, Al-Qassim Branch, Saudi Arabia ¤ alreh@ yahoo.com The cereal nematode, Heterodera avenae , is a major limiting factor in wheat production in the Al-Qassim area, Saudi Arabia. Heterodera avenae was rst reported in a wheat eld of the Al-Bekeria governorate of Al-Qassim in 1987 but, over the last 5 years, it has spread in the major wheat elds of most of the Al-Qassim governorates. Because of the lack of an economic alternative, wheat is grown continuously and such eld practice allowed the cereal cyst nematode population to rise above damaging thresholds. In some heavily infested elds of Al-Qassim, the nematode population has reached 250 juveniles/g. Nematode control relies on the use of non-fumigant nematicides. Application of oxamyl nematicide as a foliar spray after wheat emergence is a common practice and often results in increases in the grain yield, but it has not reduced the nematode population below damaging thresholds for the next season. Recently, ploughingthe top soil two to three times during summer time (solarisation), rotation with alfalfa or a vegetable crop, and application of organophosphate nematicides as a seed dressing have given encouraging results and have been recommended as a management practice for H. avenae control in wheat elds of the Al-Qassim area, Saudi Arabia. 387 Nematodes from the dorylaimid and mononchid orders associated with Canary Island crops Susana C. A RCOS 1 ; ¤ , Domingo J IMÉNEZ -G UIRADO 2 and Antonio B ELLO 1 1 Dpto de Agroecología, CCMA, CSIC, Serrano 115 dpdo 28006 Madrid, Spain 2 Dpto de Biología Animal, Universidad de Córdoba, Campus de Rabanales, Edi cio C-1, 14071 Córdoba, Spain ¤ scobacho@ccma.csic.es In order to ascertain the effect that agricultural practices produce on the most representative species of dorylaimids and mononchids in the Canary Islands, the nematode col- lection at the Department of Agroecology of the Envi- ronmental Sciences Center (CSIC) was reviewed, where the majority of environments cultivated in Spain are rep- resented. A total of 750 samples were studied. Nineteen species of the dorylaimid order were found, the most frequent being: Aporcelaimellus obtusicaudatus and Be- londira tarjani (3.9%), followed by Discolaimus texanus , Eudorylaimus leuckarti , Nygolaimus brachyuris and Oxy- dirus oxycephalus (2.6%). Of the samples studied, seven species were identi ed from the mononchid order, the most frequent being, in order: Mylonchulus sigmaturus (36%), Clarkus papillatus (13.1%) and Mononchus trun- catus (3.9%). The dorylaimids demonstrated greater di- versity while the mononchidspresented greater frequency, since the latter nematodes are more susceptible to changes caused by anthropic action. Nematodes from the dory- laimid and mononchid orders are of interest because they are bioindicators of the level of alteration that agrarian systems have undergone. 388 Plant-parasitic nematodes associated with a sugar beet rotation system in central Portugal: possible implications on production Pedro B ARBOSA ¤ and Manuel M OTA NemaLab/ICAM, Departamento de Biologia, Universidade de Évora, 7000 Évora, Portugal ¤ nemalab@uevora.pt Today, at least 37% of the world’s sugar is produced from sugar beet. In many growing areas, nematodes are amongst the most important pests; capable of causing irreversible damage and unacceptable economical crop loss. Population dynamics of plant-parasitic nematodes is essential to anticipate crop damage caused by these pathogens and parasites. The Coruche region in the province of Ribatejo, Portugal, is the location of a major sugar beet production region. A preliminary survey and study was conducted during 2001 to evaluate the presence of taxa and their relative abundance from three elds where a sugar beet-corn rotation system is in use. The main phytoparasites collected belonged to the genera Meloidogyne , Helicotylenchus , Pratylenchus , Tylenchorhynchus , Trichodorus and Heterodera . Two sampling seasons were established: autumn and spring; 200 g soil samples were collected for nematode extraction, which was performed according to two 260 Nematology</p>
<p>Poster sessions methods: Baermann funnel and centrifugal otation. Nematodes were counted using an inverted microscope and photographedwith a digital camera, from a compound microscope. Helicotylenchus sp. appears to be particularly numerous, and may be mainly responsible for causing a negative effect on the crop. 389 Host range study of an undescribed Meloidogyne sp. isolated from groundnut Ivan F. B ENDEZU ¤ and James L. S TARR Texas A & M University, Plant Pathology & Microbiology Dept., College Station TX 77843-2132, USA ¤ ibendezu@hotmail.com The reproduction of a new Meloidogyne sp. (93-13) isolated from groundnut in Collingsworth County (Texas) was tested against a range of different plants species and compared to a population of Meloidogyne arenaria race 1. Pea cvs Progress and Early Snap were moderate hosts (RF D 1 : 57 and 1.18). The bean cvs Bountiful and Blue Lake 274 had low reproductive rates (RF D 0 : 69 and 0.75) of Meloidogyne sp. 93-13, whereas Pea cv. California Blackeye 5 and 46, and Clemson Purple (RF D 0 : 05, 0.02 and 0.09) were resistant. Genetically modi ed (Roundup Ready) soyabean cvs HBKR 4660, 4855, 4920, 5588, 5920, 6020, 6600, and conventional soyabean cultivars HBK 4891, 5990, 5991, were also tested. The best soyabean with resistance to the two species of root-knot nematodes is HBKR 4660, followed by HBKR 6020 with high levels of resistance to M. arenaria , and HBK 5991 with intermediate levels of resistance to M . sp. 93-13. A comparison between the conventional and the genetically modi ed soyabeans did not show any signi cant difference ( P D 0 : 05 / in any of the variables evaluated. 390 Cotton nematode distribution and density in the USA Donald J. B LASINGAME 508 Colonial Circle, Starkville, MS, 39759, USA Db508pb@aol.com In 1986 a nematode survey was started in the state of Mississippi. A beltwide program was initiated in 1989 under the direction of the National Cotton Council and with industry support. The purpose of the survey was to determine nematode species and population densities. Yield losses were also determined as each state used a standard treatment of control. Yield losses were determined by using nematicides compared to an untreated control. The survey has been completed on more than 60% of the cotton producing counties and parishes in the USA. The major species found in the survey are root-knot, reniform, lance, and sting nematodes. The root- knot nematode is found in most areas where cotton is grown. The reniform nematode is prevalent in the south- east and mid-south sections of the cotton belt. The lance and sting nematodes are concentrated in the southeast. The survey maps show the three major species present and their relative population levels. These maps are updated annually and can be seen on the National Cotton Council web site at http://www.cotton.org/cf/nematodes. 391 First records of Bursaphelenchus species in Thailand Helen B RAASCH 1 ; ¤ and Rainulf B RAASCH -B IDASAK † 1 Kantstraße 5, D-14471 Potsdam, Germany † died in 2001 ¤ h.braasch@t-online.de The damage caused by the pine wood nematode ( Bursaphelenchus xylophilus ) in several East Asian countries (Japan, China, Taiwan) and its easy spread by the timber trade provoked scienti c interest in tree- inhabiting Bursaphelenchus species. Thailand is a country with high temperatures which make it favourable for the development of pine wilt caused by B. xylophilus . Pine forest occurs naturally in small tracts in some upland areas at altitudes between 800 and 1800 m. Native pines are Pinus merkusii and P. kesiya. Wood samples collected in North Thailand were examined for the presence of Bursaphelenchus spp. The species found were Bursaphelenchus hylobianum, B. mucronatus as well as two undescribed species. The pine wood nematode was not present in these samples. However, the occurrence of B. mucronatus , a species closely related to B. xylophilus and transmitted by the same vectors ( Monochamus spp.), indicates the possible establishment of B. xylophilus in case of its introduction to Thailand. Special quarantine attention should be paid to wood imports (sawn coniferous timber, logs, wooden packaging material) from countries where the pine wood nematode occurs. 392 Nematode genera associated with mango in Zulia State, Venezuela Vol. 4(2), 2002 261</p>
<p>Distribution, population dynamics (383-443) E. B RICEÑO 1 , N. J IMÉNEZ 1 , Q. Q UIJADA 2 and G. C ASTELLANO 2 1 Decanato de Agronomía, Dpto. Ciencias Biológicas, Apdo 400, Barquisimeto, Estado Lara, Venezuela 2 Instituto de Investigaciones Agrícolas (INIA-Zulia). Apdo 1316, Maracaibo, Estado Zulia, Venezuela biblio_zulia@impast.net.ve We have identi ed nematode genera associated with mango ( Mangifera indica L.) in Zulia state. Forty sam- ples of roots and soil from production farms in Mara and Urdaneta Municipality were processed with a combina- tion of Oostenbrink funnels and Baermann pans. Roots were ground at low speed. Results showed the presence of Hemicriconemoides, Xiphinema, Meloidogyne, Hoplo- laimus, Rotylenchulus, Tylenchus , Trichodorus and Ty- lenchorhynchu s in Mara-Urdaneta, with the highest fre- quency for Rotylenchulus,Hoplolaimus and Meloidogyne . A brief description is reported and identi cation key is proposed. 393 Nematode pests of potato in the mesothermic valleys of the Andean region, Santa Cruz Department, Bolivia John B RIDGE 1 ; ¤ , Ernesto M ONTELLANO 2 , Noel O RTUÑO 3 , Oscar D IAZ 2 , Pablo F RANCO 2 , David H UNT 1 and Janet R OWE 4 1 CABI Bioscience, Bakeham Lane, Egham, Surrey TW20 9TY, UK 2 CIAT, Ejercito Nacional 131, Casilla 247, Santa Cruz de la Sierra, Bolivia 3 Fundacion PROINPA, Av. Blanco Galindo Km 12.5, Calle Prado s/n, Casilla 4285, Cochabamba, Bolivia 4 IACR Rothamsted, Harpenden, Herts AL5 2JQ, UK ¤ J.Bridge@cabi.org The mesothermic valleys in the Andean region of the Santa Cruz Department occur at altitudes of 1400 to 2500 m a.s.l. Potato production, both with Solanum tuberosum var. tuberosum and S. tuberosum var. andigena , has increased in these warmer mid-altitude valleys. Intensi cation of potato cropping systems has led to increased severity of a complex of potato diseases including nematodes. Over 70 farm elds were examined in seven valleys. All the three main nematode groups: the root-knot nematodes, Meloidogyne spp. (mainly M. incognita and M. javanica but also M. hapla ), the false root-knot nematode, Nacobbus aberrans , and the potato cyst nematodes, Globodera spp. . mainly G. pallida but also G. rostochiensis plus G:. ? /tabacum/ were found. Meloidogyne species occurred in over 30% of farms; Nacobbus in 20%; and Globodera also in over 20%. Seed tubers are moved from the traditional potato growing areas in the higher and cool altiplano and both Meloidogyne and Nacobbus were found in these seed tubers. Thirty parasitic species were found on potato and another undescribed species of Globodera was also identi ed, occurring in large numbers on the roots of Brassica rapa. 394 Nematode genera associated with merey ( Anacardium occidentale ) in Zulia state, Venezuela G. C ASTELLANO 1 , O. Q UIJADA 1 , N. J IMÉNEZ 2 and E. B RICEÑO 2 1 Instituto Nacional de Investigaciones Agrícolas, INIA-Zulia, Apdo. 1316. Maracaibo, Zulia, Venezuela 2 UCLA, Decanato de Agronomía Dpto de Ciencias Biológicas, Apdo. 400 Barquisimeto Estado Lara, Venezuela biblio_zulia@impast.net.ve In order to identify the main nematodes associated with merey ( Anacardium occidentale ) in Zulia state, a survey of nematodes was performed in Mara municipality farms and 60 soil and root samples were taken. The samples were processed with a combination of Oostenbrink and Baermann funnel equipment. Results showed the pres- ence of Dorylaimus, Aphelenchus, Tylenchus , Helicoty- lenchus, Tylenchorhynchus,Criconemoides, Hoplolaimus and Xiphinema , with Aphelenchus as most common fol- lowed by Helicotylenchus. Finally, a brief description is reported and an identi cation key is proposed. 395 Plant-parasitic nematodes associated with semeruco in Zulia State of Venezuela G. C ASTELLANO 1 , O. Q UIJADA 1 , N. J IMÉNEZ 2 and E. B RICEÑO 2 1 Instituto Nacional de Investigaciones Agrícolas, INIA-Zulia, Apdo. 1316. Maracaibo, Zulia, Venezuela 2 UCLA, Decanato de Agronomía Dpto de Ciencias Biológicas, Apdo. 400 Barquisimeto Estado Lara, Venezuela Biblio_zulia@impast.net.ve Plant-parasitic nematodes affect production in most crops in Mara Municipality Zulia state. In order to evaluate the nematodes in semeruco ( Malpighia glabra L.) crops, a nematological sampling was performed where 60 soil and roots samples were analysed. Samples were processed with a combination of Oostenbrink and Baermann funnel 262 Nematology</p>
<p>Poster sessions equipment. Roots were ground at low speed. Seven genera were identi ed: Meloidogyne , Criconemoides, Discolaimus, Dorylaimus, Tylenchus, Hoplolaimus and Acrobeles . The genus Meloidogyne was found to be the main genus. A brief description is given and an identi cation key is proposed. 396 Heterodera mediterranea : biological observations with emphasis on factors affecting egg hatching and differential responses of olive cultivars to infection Pablo C ASTILLO 1 and Nicola V OVLAS 2 1 Instituto de Agricultura Sostenible, CSIC, Apdo. 4084, 14080 Córdoba, Spain 2 Istituto di Nematologia Agraria Applicata ai Vegetali, C.N.R., Via G. Amendola 165/A, 70126 Bari, Italy The in uence of temperature and olive root exudates on Heterodera mediterranea egg hatch and the effects of H. mediterranea on the growth of two olive cultivars (Arbequina and Picual) were investigated. Egg hatch occurred over a temperature range of 10-30 ± C and was optimal at 20-25 ± C. There were no differences in egg hatch between sterile deionised distilled water or root exudate dilutions (undiluted, diluted 1 : 1, and 1 : 2) of Arbequina and Picual at 20 ± C. Heterodera mediterranea reproduced on both olive cultivars in growth chambers at 25 ± C. Soil and root nal nematode populations, as well as total number of cysts per plant and reproduction rate, were signi cantly higher in Arbequina than in Picual. Shoot dry and root fresh weights, and increases of shoot height, trunk diameter and numbers of nodes were signi cantly suppressed by infection with 10 000 eggs C second stage juveniles/pot in Arbequina but not in Picual. Heterodera mediterranea completes its life cycle (embryogenic and postembryogenic development) in about 60-70 days on olive roots. Syncytia formation and disorder of root stellar structure are the main anatomical changes induced by the parasite on olive cvs Arbequina and Picual roots. 397 Survey of nematodes in Andean potato elds of northwest Argentina Eliseo C HAVES ¤ , Eduardo M ONDINO and Andrea C LAUSEN INTA EEA Balcarce, C. Correo 276, 7620 Balcarce, Argentina ¤ echaves@balcarce.inta.gov.ar A germplasm collecting expeditionwas carried out during the autumn of 2001 to collect Andean potato cultivars ( Solanum tuberosum ssp. andigena ) in the province of Jujuy, Argentina (23 o S). Local farming practices usually involve the purchasing or bartering of varieties in market places but in a few cases some varieties are sold in major centres. As some nematodes are a potential threat for the cultivation of the potato, the detection of the species present in the potato-growing areas is needed in order to establish quarantine methods. Twenty- ve sites situated at altitudes ranging from 2370 to 3885 m were sampled and nematodes extracted from 100 cm 3 of soil with modi ed centrifugation- otation technique. Sixty- ve genera of nematodes were found in the samples. The plant-parasitic nematodes were mostly represented by Pratylenchus sp. (69%), Meloidogyne sp. (65%) and Nacobbus aberrans (61%). Four new localities were added to the distribution of Globodera tabacum in the region. The bacterial-feeders were represented mainly by Chiloplacus (77%), Rhabditis and Seleborca (42%); fungivores by Aphelenchus (96%), Ditylenchus (85%) and Aphelenchoides (57%); predators by Aporcelaimellus (54%) and omnivores by Ecumenicus (35%). The genera Bitylenchus, Butlerius, Cervidellus, Crassolabium, Dolichorhynchus, Enchodelus, Labronemella, Seleborca, Stegelleta and Zeldia are new records for Argentina. 398 Nematodes of citrus in open nurseries and orchards in São Paulo State, Brazil Anderson S. DE C AMPOS 1 , Jaime M. DOS S ANTOS 2 ; ¤ and Larry W. D UNCAN 3 1 ; 2 UNESP/Faculdade de Ciências Agrárias e Veterinárias, Via de Acesso Prof. Paulo Donato Castellane s/n, 14884.900 Jaboticabal, SP, Brazil 3 Univ. of Florida – IFAS, Citrus Research and Education Center, University of Florida, 700 Experiment Station Rd, Lake Alfred, FL 33850, USA ¤ jmsantos@fcav.unesp.br A survey of key-nematodes of citrus was conducted in open nurseries and orchards in São Paulo State Brazil. Totals of 2518 samples from 595 nurseries in 99 counties, and 1078 samples from commercial orchards in 86 counties were examined. The nematodes were separated from 100 cm 3 of sampled soil by centrifugal otation and from 10 g of sampled roots by maceration in a blender followed by centrifugal otation. The citrus nematode ( Tylenchulus semipenetrans Cobb) was found in 34% of the nurseries and in 72.5% of the commercial Vol. 4(2), 2002 263</p>
<p>Distribution, population dynamics (383-443) orchards. Putative populations of Pratylenchus coffeae (Zimmermann) Filipjev & Schuurmans Stekhoven were found in seven nurseries and ten orchards. These populations pertain to a new species of lesion nematode that is being described and named Pratylenchus jaehni. Maps of the distribution of these nematodes throughout the main region of citrus production in São Paulo State were prepared. 399 Nematode problems in Castilla y Leon (Spain), a continental Mediterranean climate Miguel A. D ÍEZ , Miguel E SCUER and Antonio B ELLO ¤ Dpto Agroecología, CCMA, CSIC, Serrano 115, 28006 Madrid, Spain ¤ antonio.bello@ccma.csic.es Plant-parasitic nematode problems were analysed in the region of Castilla y Leon, northwestern Iberian Peninsula. Nematode groups, in the order of their importance, are: i ) cyst nematodes, represented by Globodera rostochienis and G. pallida in potato, Heterodera schachtii in sugar- beet, H. avenae in cereal, and H. humili in hops; ii ) the root-knot nematode M. incognita in sugar-beet and potato; iii ) virus vector nematodes, among which Xiphinema index stands out, of interest in vineyards; iv ) bulb and stem nematodes, Ditylenchus dipsaci in garlic; v ) the endoparasitic nematodes Pratylenchus, Pratylenchoides and Zygotylenchus; vi ) ectoparasitic nematodes, where Macroposthoniaxenoplax stands out for causing chlorosis in grape and fruit trees ( Prunus spp.). Species from the Amplimerlinius, Anguina, Aphelenchoides, Bitylenchus, Criconema , Criconemella, Criconemoides, Crossonema, Helicotylenchus, Hemicriconemoides, Hemicycliophora, Hoplolaimus, Longidorus, Macroposthonia, Merlinius, Ogma, Paratrichodorus, Paratylenchus, Quinisulcius, Rotylenchus, Scutellonema, Seriespinula, Trichodorus, Tylenchorhynchus and Xenocriconemella genera were also found. Various control alternatives are indicated, such as preventativepractices and crop rotation, which regulate the development of pathogenic nematode populations as well as the appearance of phytopathological problems. These alternatives must be followed by the use of resistant plants and trap crops within an integrated production system. 400 Heterodera glycines distribution within a eld in no-till production over time Patricia A. D ONALD ¤ , Kenneth A. S UDDUTH and Newell R. K ITCHEN USDA ARS 605 Airways Blvd, Jackson, TN 38301, USA; USDA ARS 269 Ag. Engineering Bldg, University of Missouri, Columbia, MO 65211, USA ¤ pdonald@ars.usda.gov Heterodera glycines (SCN) is a major pest of soybean causing signi cant yield losses when present and when management techniques to reduce egg population density are not used. A study investigated the distribution of SCN at planting and harvest in a claypan soil eld in central Missouri under no till soybean production. Comparisons were made in the nematode distribution in 1999 and 2001 years of soybean production. Nematode distribution in the 2 years was compared to yield, topsoil thickness, elevation, and soil nutrient maps. Nematode distribution was most closely correlated with topsoil thickness ( i.e ., depth to the claypan). Lower H. glycines population density occurred in areas with shallow topsoil thickness. 401 Tobacco rattle virus and its associated vector trichodorid nematodes in Portugal I.M. D UARTE 1 ; ¤ , M.T.M. A LMEIDA 2 and D.J. B ROWN 3 1 Escola Superior Agrária de Coimbra, Coimbra, Portugal 2 Departamento de Biologia, Universidade do Minho, Braga, Portugal 3 Nematology Department, Scottish Crop Research Institute (SCRI), Dundee, Scotland, UK ¤ iduarte@mail.esac.pt Tobacco rattle virus (TRV, genus Tobravirus ), transmitted by trichodorid nematodes, occurs as a wide range of serologically distinguishable strains that cause diseases in various economically important crops. The virus and its associated vector nematodes occur world-wide, being particularly prevalent in Europe and North America. In Portugal, an investigation is being conducted to identify TRV strains occurring in association with their natural vector species. The project has focused on potato growing areas in northern and central Portugal, with soil sampling biased in favour of areas where TRV-like symptoms have been reported. Nematodes were extracted from soil and phenotypically identi ed. TRV was recovered from nematodes in virus transmission studies, and identi cation con rmed using sap transmission tests, a leaf squash method with EM, ELISA, ISEM, and RT-PCR. Trichodorids were recovered frequently from potato elds, and the species identi ed were: Trichodorus 264 Nematology</p>
<p>Poster sessions lusitanicus , T. primitivus , Paratrichodorus anemones , P. hispanus , P. minor , P. pachydermus , also three new undescribed species and an unidenti ed Paratrichodorus species. TRV occurred in four of 58 (7%) soil samples in association with trichodorids: one in the north and the others in the centre of the country. Molecular characterisation of the TRV isolates and their associated vector trichodorids is presently in process. 402 Nematodes associated with coniferous woods in Spain Miguel E SCUER ¤ , María A RIAS and Antonio B ELLO Dpto Agroecología, CCMA, CSIC, Serrano 115 dpdo, 28006 Madrid, Spain ¤ escuer@ccma.csic.es Nematodes associated with coniferous woods in Spain were studied in 2000-2001. Sampling was coordinated by the Spanish Ministry of Agriculture, Fisheries and Food, with the cooperation of the of cial forestry, plant health services and diagnostic laboratories of several au- tonomous communities. Seven nematode genera were found on conifer trees. Laimaphelenchus penardi , the most widespread species in the Peninsula and on the Balearic Islands, was found associated with Abies alba , Pinus nigra , P. pinaster and P. pinea ; Cryptaphelenchus spp. and Deladenus spp. are also widespread, but their species are under study. Seven species of Bursaphelen- chus were found, B. sexdentati being the most widespread in Peninsular Spain associated with Pinus spp. Bursaphe- lenchus eggersi and B. mucronatus appeared in northern Spain associated with Abies alba and Pinus pinaster , and on Pinus halepensis and Pinus spp., respectively. Other species are more localised: B. fungivorus on P. pinaster in the Cazorla mountains, Andalusia; B. leoni and B. ter- atoespicularis restricted to the Balearic Islands on Pinus halepensis in Mallorca and Ibiza; B. pinasteri appearing once on Pinus pinaster in Extremadura; Aphelenchoides daubidaensis , A .jonesi and Ektaphelenchus macrobulbo- sus on P. pinaster and P. nigra in the west, and nally, Seinura spp. on Pinus spp. from northeastern Spain. 403 Nematode problems in the region of Murcia (Spain), a Mediterranean model Miguel E SCUER 1 ; ¤ , Ana C ANO 2 and Antonio B ELLO 1 1 Dpto Agroecología, CCMA, CSIC, Serrano 115 dpdo, 28006, Madrid, Spain 2 Servicio Protección y Sanidad Vegetal, Estación Sericícola, c/Mayor s/n, 30150 La Alberca, Murcia, Spain ¤ escuer@ccma.csic.es Plant-parasitic nematode problems in the region of Mur- cia in the southeastern Iberian Peninsula were analysed. The nematode groups, in the order of their importance are: i ) the root-knot nematodes, Meloidogyne arenaria , M. incognita and M. javanica , which affect horticultural crops and fruit trees; ii ) virus vector nematodes, among which Xiphinema index , of interest in vineyards, stands out; iii ) the citrus nematode, Tylenchulus semipenetrans , found in citrus orchards and vineyards; iv ) cyst nema- todes, represented by Heterodera cruciferae in broccoli, H. latipons in oats and H. schachtii in chard; v ) the en- doparasitic nematodes Pratylenchus and Pratylenchoides ; and vi ) ectoparasitic nematodes, among which Macro- posthonia xenoplax stands out for causing chlorosis in grape vines and fruit trees ( Prunus spp.). Species were also found from the genera Criconema , Criconemella, Criconemoides, Crossonema, Hemicriconemoides, Heli- cotylenchus, Merlinius, Paratylenchus, Rotylenchus and Tylenchorhynchus . Various control alternatives are indi- cated, especially preventative practices to regulate the de- velopment of pathogenic nematode populations and to prevent the appearance of phytopathological problems, followed by the use of resistant plants and biofumigation, all within an integrated production system. 404 Distribution of Globodera tabacum in the La Vera region of Spain G. E SPARRAGO 1 , I. B LANCO 2 and I. P ULIDO 1 1 Servicio de Investigación y Desarrollo Tecnológico, Junta de Extremadura, Finca La Orden, 06187 Guadajira, Badajoz, Spain 2 CETARSA Finca La Cañalera, Ctra Santa María de las Lomas, Km 3,5 10310 Talayuela, Cáceres, Spain La Vera is the principal tobacco growing area in Spain. Every year 11 000 ha of ue-cured and 2500 ha of burley tobacco are produced in monoculture. The most important phytonematological problem in the crop is caused by root- knot nematodes. However, in August 2001 Globodera tabacum was rst detected over a K326 ue-cured variety eld. To know the incidence of these cyst nematodes in this tobacco region, a survey of Globodera populations was carried out during February 2002. 82 soil samples were gathered in elds where tobacco was cultivated in 2001. Soil was analysed for nematode abundance (cyst and second juveniles). Globodera is widely distributed Vol. 4(2), 2002 265</p>
<p>Distribution, population dynamics (383-443) across the region. Abundance and distribution of this nematode in the La Vera tobacco area is shown. 405 Characterisation of cereal cyst nematodes, Heterodera spp., in Norway Ricardo H OLGADO 1 ; ¤ , Stig A NDERSSON 2 and Janet R OWE 3 1 The Norwegian Crop Research Institute, Plant Protection Centre, Dept. of Entomology and Nematology, Høgskoleveien 7, N-1432 Ås, Norway 2 Swedish University of Agricultural Sciences, Dept. of Crop Science, Box 44, S-230 53 Alnarp, Sweden 3 IACR-Rothamsted, PPI Division, Nematode Interaction Unit, Harpenden, Herts, AL5 2JQ, UK ¤ ricardo.holgado@planteforsk.no Cereal cyst nematodes (CCN), Heterodera spp., are common pests of cereal crops in Norway. Fifteen populations were investigated morphologically, through biotests, and through electrophoretic studies, using isoelectric focusing and silver staining of proteins. In the biotest the populations were grouped by their virulence on barley differentials (resistance genes) Varde ( Rha ), Emir ( Rha“E” ), Ortolan ( Rha1 ), KVL 191 ( Rha2 ), Siri ( Rha2 ) and Morocco C.I. 3902 ( Rha3 ). Eleven populations expressed themselves as H. avenae pathotype Ha11. These were all fairly similar morphologically and electrophoretically. The biotest further suggested two populations belonging to pathotype Ha12. One of them was morphologicallyand electrophoretically similar to H. avenae ; the other different in both respects, indicating a possible undescribed species. Two other populations appeared to be H. lipjevi , pathotype ‘West’. One population under study was different in all aspects, morphologically,in the biotest and biochemically. Earlier studies in Norway have also indicated the occurrence of CCN pathotype Ha51. Thus, the situation in Norway regarding the CCN is very complicated. 406 First year interim results of investigations on the nematode fauna in the pedobiocoenosis of grape phylloxera ( Dactylophora vitifolii ) infested vines ( Vitis vinifera ) in selected Austrian vine production areas Michael H OSCHITZ Institute of Plant Protection, University of Agricultural Sciences, Peter Jordan Straße 82, A-1190 Wien, Austria mischahoschitz@hotmail.com Investigations about the potential correlation between the occurrence of plant-parasitic nematodes and the increased grape phylloxerainfestation of vines in Austrian vineyards are being carried out within a 3 year research project. Roots and soil adhering to the roots were investigated. In 2001, more than 100 samples in total were collected from eight selected vineyards in Lower Austria and Burgenland at monthly intervals from May to August. Subsamples of both highly phylloxera-infested and uninfested grapevines were checked for the presence of free-living and plant-parasitic nematodes, applying standard extraction methods. The predominant nematode genera, which were regularly detected and identi ed in infested as well as in uninfested root samples, were Aphelenchus sp., Aphelenchoides sp. and Helicotylenchus sp. Plant-parasitic nematodes from eight families and free-living nematodes from 14 families were identi ed from soil samples. Prospects for the investigationsin 2002 are presented. 407 A survey study of phytoparasitic nematodes and the associated host plants in Egypt I.K.A. I BRAHIM Department of Plant Pathology, Faculty of Agriculture, Alexandria University, Alexandria, El-Shatby 21545, Egypt Information concerning the occurrence and distribution of phytoparasitic nematodes is very important to assess their potential to cause economic damage to many crop plants. A nematological survey was conducted to determine the genera and species of phytoparasitic nematodes and the associated host plants in Egypt. The results indicated the occurrence of about 56 genera and 180 species of phytoparasitic nematodes associated with many cultivated plants, grasses and weeds. Many of these nematodes, e.g ., Criconemella spp., Helicotylenchus spp., Heterodera spp., Hoplolaimus spp., Meloidogyne arenaria , M. incognita , M. javanica , Pratylenchus spp., Rotylenchulus reniformis , Tylenchorhynchus spp., Tylenchulus semipenetrans and Xiphinema spp. are considered limiting factors in crop production in Egypt. 408 Comparison of boarding ability between Bursaphelenchus xylophilus and B. mucronatus on their vectors, Monochamus alternatus and M. saltuarius Shota J IKUMARU 1 ; ¤ and Katsumi T OGASHI 2 266 Nematology</p>
<p>Poster sessions 1 Hiroshima Prefectural Forestry Research Centre, Miyoshi, Hiroshima 728-0015, Japan 2 Faculty of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8521, Japan ¤ QWL06757@nifty.ne.jp Bursaphelenchus xylophilus , the causative agent of pine wilt disease, has been introduced from North America to Japan and displaced the closely related, native nematode, B. mucronatus , in the disease infestation area because the two nematode species occupy the same niche in the pine forest ecosystem. Both nematode species enter the tracheal system of newly emerged adult beetles in the genus Monochamus within pupal chambers of the beetles in xylem. To compare the boarding ability of two nematode species on the beetles, one of the plausible processes of nematode displacement, post- diapause larvae of M. alternatus or M. saltuarius were placed individually in arti cial pupal chambers of Pinus densi ora bolts inoculated with B. xylophilus or B. mucronatus . Bursaphelenchus xylophilus load on beetles was signi cantly greater than B. mucronatus load for the two Monochamus beetles, although there was no difference in the abundance of dispersal juveniles around the pupal chamber between the two nematode species. These results showed an extremely low ability of B. mucronatus to board the beetles compared with B. xylophilus . 409 Acquisition, retention and transmission of tobravirus particles by trichodorid nematodes Eirini K ARANASTASI 1 , Derek J.F. B ROWN 3 , Ian R. R OBERTS 3 and Urs W YSS 2 1 Benaki Phytopathological Institute, 8 St. Delta st, 14561 Ki ssia, Greece 2 Institute of Phytopathology, University of Kiel, Hermann-Rodewald-Str. 9, D-24118 Germany 3 Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK bpilibr@otenet.gr Tobraviruses are naturally transmitted by plant-parasitic Trichodorus and Paratrichodorus nematodes. Trichodor- ids are assumed to acquire virus particles upon sap in- gestion from virus infected root cells. Subsequently,these particles are retained on the cuticle lining the nematode pharyngeal wall and thereafter are released into further cells upon salivation of pharyngeal secretions. Real-time observations of living trichodorids feeding on roots of to- bacco seedlings revealed that although attached cells are customarily killed, a 5-10% proportion is probed, the cell walls are apparently perforated; however, the nematodes depart prior to sap ingestion, thus leaving these cells alive. Additionally, transmission electron microscopy study re- vealed differences in the sites of retention of serologically distinguishable tobravirus strains in the pharynx of dif- ferent (Para)trichodorus vector and non-vector species, i.e. , it revealed three different patterns of retention. Sub- sequently, immunogold labelling with antisera designed speci cally to identify these tobravirus strains from one another and from other viruses, provided unequivocal evi- dence of the tobra-viral identity of virus-like particles ob- served within the pharyngeal lumen of the examined tri- chodorid species. 410 Distribution and temporal population dynamics of Meloidogyne incognita and Thielaviopsis basicola in an Arkansas cotton eld T.L. K IRKPATRICK 1 ; ¤ , C.S. R OTHROCK 2 , W. K INKAID 3 , A. M AUROMOUSTAKOS 4 , W. B AKER 5 and M. D ANIELS 6 1 University of Arkansas (UoA) Southwest Research and Extension Center, 362 Highway 174 North, Hope, AR 71801, USA 2 UoA Department of Plant Pathology, 217 Plant Sciences, Fayetteville, AR 72701, USA 3 UoA at Pine Bluff, 1200 North University Drive, Pine Bluff, AR 71611, USA 4 UoA Agricultural Statistics Laboratory, AGRX 101, Fayetteville, AR, USA 5 Arkansas State University College of Agriculture, P.O. Box 2340, Jonesboro, AR 72467, USA 6 Arkansas Cooperative Extension Service, P.O. Box 391, Little Rock, AR 72203, USA ¤ tkirkpatrick@uaex.edu Thielaviopsis basicola (Berk. & Broome) Ferraris, causal agent of black root rot of cotton, and the root- knot nematode, Meloidogyne incognita , frequently occur together in cotton elds in Arkansas. Where both organisms occur together, black root rot in seedlings is signi cantly more severe and seedling mortality is greatly increased. Infection of cotton seedlings by the nematode appears to broaden the temperature range at which T. basicola can infect the seedlings, and the nematode provides the fungus access to the vascular tissue of the plant that is not normally invaded in the absence of the nematode. A 6.6 ha cotton eld in southeastern Arkansas, with a history of severe seedling disease and root-knot Vol. 4(2), 2002 267</p>
<p>Distribution, population dynamics (383-443) nematode damage, was divided into 512 grids (4 £ 30 m) and sampled prior to planting a cotton crop (April 2001) and immediately after cotton harvest (October 2001) to determine the population densities of both T. basicola and M. incognita in each grid. In addition, nematode populations were monitored in 80 arbitrarily selected grids at monthly intervals during the growing season. Spatial and temporal relationships of these organisms and their relationship to various edaphic factors are described. 411 Presence of Heterodera trifolii Goffart, 1932 (Nematoda: Tylenchida) in Argentina Paola L AX 1 , Marcelo E. D OUCET 1 ; ¤ and Eduardo V EGA 2 1 Laboratorio de Nematología, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, C.C. 122, 5000, Córdoba, Argentina 2 Estación Experimental Regional Agropecuaria Rama Caída, C.C. 79, 5600 San Rafael, Mendoza, Argentina ¤ mdoucet@gtwing.efn.uncor.edu The analysis of roots of Trifolium repens and of the soil around them, from the locality of Malargüe, province of Mendoza, Argentina, permitted the identi cation of representatives of the nematode Heterodera trifolii . White females with masses of eggs and cysts were observed on roots; second-stage larvae were extracted from the soil. Morphological and morphometric studies performed on these specimens con rm the species identity, which is cited in Argentina for the rst time. 412 Nematodes in international quarantine legislation Paul S. L EHMAN Florida Department of Agriculture and Consumer Services, DPI, P.O. Box 147100, Gainesville, FL 32614-7100, USA The Society of Nematologists currently has a USDA funded project to list and rank exotic nematodes of regulatory concern to the USA. A list of nematodes, which are regulated by international quarantine legislation in 2002, was compiled using the APHIS/USDA data base, and was compared to Kahn’s 1982 list of the ten most frequently regulated nematodes. In general, in the past two decades the number of countries regulating nematodes has increased. For example, 51 countries regulated Globodera rostochiensisi s in 1982, but 106 countries regulate it in 2002. Worldwide, G. rostochiensisi s is the most regulated nematode and ranks second only to potato wart fungus, Synchytrium endobioticum (108 countries) in a list that includes regulated insects pests and plant pathogens. The rank for many nematodes has changed the past two decades, which indicates that regulations are not static. For example, in 1982 Aphelenchoides besseyi ranked tenth and was regulated by nine countries, but in 2002 it ranked second with 70 countries regulating it, primarily to protect rice crops. In contrast, in 1982 11 countries had regulations to exclude Meloidogyne javanica , but in 2002 no country listed it as a prohibited nematode. 413 Biogeographicalcharacterisation of Trichodoridae in the Iberian Peninsula J. Antonio L ÓPEZ -P ÉREZ 1 ; ¤ , M. Teresa A LMEIDA 2 , María A RIAS 1 and Antonio B ELLO 1 1 Dpto Agroecología, CCMA, CSIC, Serrano 115 dpdo, 28006 Madrid, Spain 2 Dpto Biologia, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal ¤ pezperez@ccma.csic.es The existence of two faunistic groups have been found on analysis of the distribution patterns of the 18 species from the family Trichodoridae that have been found in representative crops and environments of the Iberian Peninsula. The rst one represented by the autochthonous species, Paratrichodorus hispanus , Trichodorus azorensis, T. beirensis, T. giennensis and T. lusitanicus , is present in uncultivated and cultivated areas; T. azorensis, T. beirensis and T. giennensis have been found very localised, while P. hispanus is widespread in Spain and northern Portugal and T. lusitanicus is common mainly in southern but also found in central Portugal. The second one is de ned by the plant-parasitic and virus vector species, P. minor, P. pachydermus, P. teres, T. primitivus, T. sparsus and T. viruliferus , in which P. anemones and T. similis could also be included, in spite of their very localised presence. Paratrichodorus anemones, P. pachydermus, T. similis and T. viruliferus could be regarded as characteristic species from temperate environments, while P. minor , the most widespread species in subtropical crops, has also been found in the Canary and Madeira Islands. On the other hand, P. teres, T. giennensis, T. similis, T. sparsus and T. viruliferus have only been found in Spain, while P. acutus, P. allius, P. nanus, P. porosus, T. azorensis and T. orientalis appeared very localised only in Portugal, P. acutus, P. porosus and T. azorensis appearing only in the 268 Nematology</p>
<p>Poster sessions Azores and Madeira Archipelagos. Climatic, vegetation and soil type in uence are discussed. 414 Association of Melilotus albus Desr. with a population of Meloidogyne javanica (Treub, 1885) Chitwood, 1949 in the province of Mendoza, Argentina Eugenia L ORENZO 1 ; ¤ , Marcelo E. D OUCET 2 , Susana S UÁREZ 1 and Paola L AX 2 1 Orientación Morfología Vegetal, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Agencia Postal N ± 3, 5800, Río Cuarto, Córdoba, Argentina 2 Laboratorio de Nematología, Centro de Zoología Aplicada, Universidad Nacional de Córdoba, C.C. 122, 5000, Córdoba, Argentina ¤ elorenzo@exa.unrc.edu.ar A population of M. javanica was detected in the locality of Malargüe, province of Mendoza, infecting roots of Melilotus albus . The plant was at the owering stage at the time of analysis. Its aerial portion had a normal aspect. However, a great number of galls containing females of the nematode were observed on roots. In some galls, the posterior end of females protruded beyond the tissues; in other galls, females were inside them. Internally, giant cells were observed in the central cylinder, which reduced the vascular tissues and also caused important anomalies in their arrangement. The nematode develops its life cycle completely, producing an egg mass. It is concluded that the nematode – host relationship is close, and that the plant represents a good host for this species of the genus Meloidogyne. This weed is cited as an alternative host of a phytophagousnematode in Argentina for the rst time. 415 Population dynamics of the pine wood nematode, Bursaphelenchus xylophilus , in dead pine trees Yasuharu M AMIYA 5-6-8 Kitanodai, Hachioji, Tokyo, 192-0913 Japan CBL01545@nifty.com Experimental results of inoculation tests and observations on naturally infected pine trees demonstrated that the pine wood nematode was detected rarely in wood at the time when disease symptoms appeared, such as the cessation of oleoresin exudation from wounds. The nematode population in wood of a diseased tree increased as the disease advanced more. Nematode reproduction was rapid and a huge population developed in the wood of a diseased tree. About 50 million nematodes were calculated to be in the stem wood of a dead tree 10 m tall and 15 cm diameter at breast height. Nematodes were distributed throughout the dead tree. Spatial distribution patterns of nematodes varied considerably among dead pine trees. Aggregated distribution was demonstrated in the stem. Nematode populations in dead trees declined gradually after reaching a maximum level, about 3000 nematodes per g of dry wood, and were almost extinct in July of the following year. In this stage of the population dynamics, dispersal third stage juveniles appeared and the proportion of them in the whole population increased gradually. 416 Potato cyst nematodes, Globodera rostochiensis and G. pallida , in Swedish potato elds and their relationships to other European populations Sanja M ANDURI C ¤ and Stig A NDERSSON Swedish University of Agricultural Sciences, Department of Crop Science, Box 44, S-230 53 Alnarp, Sweden ¤ sanja.manduric@vv.slu.se Sixteen Swedish potato cyst nematode populations were compared with 19 populations from the Netherlands, United Kingdom, Germany and Norway as to genetic and virulence variability through AFLP analysis and biotests. Obtained data indicate a large heterogeneity, and the present occurrence seems to be the result of several older and more recent introductions. Swedish Ro1/Ro4 populations of Globodera rostochiensis came from heavily infested elds, had a general European appearance, and may be supposed to be very old introductions. Members of virulence group Ro2/3 of this species were genetically more heterogeneous but similar to continental populations. They may have been introduced later. Swedish G. pallida populations of virulence group Pa2/3 could according to the AFLP analysis be divided into two subgroups, one similar to a British population and the other to continental populations. G. pallida populations belonging to the ‘British’ group were pure populations and probably fairly old introductions. Pa2/3 populations of the ‘continental’ group were, with one exception, found in the starch potato district where they had been selected during intensive cultivation of cultivars with Solanum tuberosum ssp. andigena resistance. They may be fairly recent Vol. 4(2), 2002 269</p>
<p>Distribution, population dynamics (383-443) introductions. Norwegian populations of both species seemed to have backgrounds similar to the Swedish ones. 417 Nematodes from an urban forest in So a, Bulgaria Alexander M LADENOV , Stela L AZAROVA ¤ and Vlada P ENEVA Central Laboratory of General Ecology, 2 Gagarin Street, 1113 So a, Bulgaria ¤ stella_n@ecolab.bas.bg Generic composition, trophic structure, diversity and Maturity indices of nematode assemblages were studied at Knyaz Borisova Gradina City Park. The study site was a 60-90 year-old mixed deciduous-coniferous forest dominated by Quercus pedunculiora C. Koch. Litter and soil samples: decomposition layer, ca 0.5- 1 cm, and humus layer at three depths: 0-5, 5- 10 and 10-25 cm were collected. Ninety nematode genera were registered. Generally, nematode abundance was low and differed between samples and depths. Bacterial feeders were the most common, abundant and diverse (36 genera) group, followed by plant feeders (22 genera). A clear difference between litter and soil nematode assemblages was revealed in regard to almost all parameters studied. Nematode communities from decomposition and humus layers were similar in taxonomic and trophic group structure. In soil layers plant-feeding nematodes prevailed, omnivores were well represented while bacterial feeders decreased with depth. No clear layer dependent patterns in generic distribution were found. Maturity Indices of soil communities were high and their values increased gradually with depth. Nematode soil assemblages were characterised by high diversity and maturity, which could/might be related to the age, heterogeneity and size of the forest studied although it is situated in an urban environment. 418 Tourist ow effect on Nematoda of Brazilian sandy beaches Adriana M. M OELLMANN ¤ and Thaïs N. C ORBISIER Instituto Oceanográ co – Universidade de São Paulo, Praça do Oceanográ co, 191 Butantã, São Paulo, SP 05508-900, Brazil ¤ adrimoellmann@ig.com.br This study is an attempt to evaluate the impact of human activity on the Enseada Beach during summer, comparing it with the preserved Una Beach, through the study of the taxon Nematoda. At each beach, sampling was undertaken at three points along three pro les with a cupper core of 28 mm diameter to a depth of 20 cm. Each sample was divided into layers of 5 cm. Samples for sedimentological analysis were collected and temperature, salinity, pH and slope pro le measurements were made. Nematoda mean density at the Enseada Beach ranged from 719.5 ind. £ 10 cm ¡ 2 in December 98 to 1299 ind. £ 10 cm ¡ 2 in June 99. At the Una Beach mean density ranged from 751.8 ind. £ 10 cm ¡ 2 in February 99 to 1570.1 ind. £ 10 cm ¡ 2 in November 99. On the Enseada Beach in February 99, at the points where human density was higher, Nematoda was found deeper in the sediment. In March 99 Nematoda was concentrated in the rst layer of the sediment. Nematoda is being identi ed at genus level to seek for variation in vertical and temporal distribution. 419 Nematodes of Haughton Crater Peter M ULLIN 1 , Andrew S HUERGER 2 and Thomas P OWERS 1 ; ¤ 1 University of Nebraska, Department of Plant Pathology, 406 PSH, Lincoln, NE 68583-0722, USA 2 Life Sciences Program, Dynamac Co., Kennedy Space Center, FL 32899, USA ¤ Tpowers@unlnotes.unl.edu Haughton Crater has been called Mars on Earth due to presumed similarities with craters on Mars. Sixteen km in diameter, Haughton Crater is located on Devon Island, Nunavut, Canada approximately 640 km south of the north magnetic pole. Plant communities in the crater are frequently found in isolated patches surrounded by a coarse, rock and gravel substrate. The nematode communities within these ‘micro-oases’ are surprisingly diverse. To date 75 species have been identi ed. Compared with other nematode communities, the micro- oasis nematode community is dominated by predators and omnivores and includes an unexpectedly large number of males. Outside the micro-oases, a less diverse community exists, with 58 species identi ed to date, including 27 species not observed within the micro-oases. Overall nematode abundance ranged from 22 to 4129 nematodes per 100 cm 3 of soil. All nematodes observed in this study were revived from an anhydrobiotic state. The diversity and abundance of nematodes in Haughton Crater sharply contrasts with the depauperatecommunitiesof the Antarctic dry valleys. 270 Nematology</p>
<p>Poster sessions 420 Phytoparasitic nematodes associated with the rhizosphere of lulo, mora, tree tomato and granadilla plants in Colombia Gladis Emilia M ÚNERA U RIBE ¤ and Rafael N AVARRO Apartado aéreo 51764 Medellín, Colombia ¤ gladise@epm.net.co Nine genera of phytoparasitic nematodes were found associated with the rhizosphere of lulo or naranjilla ( Solanum quitoense Lam.), tree tomato or tamarillo ( Cyphomandra ( Solanum ) betacea ( betaceum) (Cav.) Sendt), granadilla ( Passi ora ligularis Juss.) and mora ( Rubus glaucus Benth.) in different Colombian regions. The genus Meloidogyne was both more prevalent and abundant in all the locations sampled. Meloidogyne incognita, M. javanica, M. hapla and M. arenaria were identi ed in the rhizosphere from lulo and tree tomato whereas M. incognita and M. hapla were found in the rhizosphere of granadilla. On the other hand some of the above mentioned nematode species were found in soil borne on mora plants but M. incognita and M. javanica, Helicotylenchus sp. and Paratylenchus sp. do not reproduce in this plant. Trichodorus , Hemicycliophora and Pratylenchus do reproduce in mora plants. Other important genera associated with all the fruit plants studied were Xiphinema, Paratylenchus, Hirschmanniella and Criconemella. A strong interaction was found between Meloidogyne incognita and Fusarium solani which reduced development and growth parameters of granadilla plants. 421 Host status of the common weeds of banana establishments to banana nematodes in Uganda J.M. N AMAGANDA 1 , I.N. K ASHAIJA 1 and R. M ASLEN 2 1 Kawanda Agricultural Research Institute, P.O. Box 7065, Kampala, Uganda 2 NR International Ltd, P.O. Box 258, Chatham, Kent ME4 4PU, UK Host status to the banana nematodes Radopholus similis , Helicotylenchus multicinctus and Pratylenchus goodeyi was studied in 13 common weed species, in a screenhouse experiment. Banana nematodes were recovered from soil, roots or both in banana and nine weed species, but nematode population densities indicate that these weed species are poor hosts of the banana nematodes. Helicotylenchus multicinctus was the only nematode species recovered from soil and occurred on banana and only six weed species, at population densities much lower than that of banana. From roots, R. similis was recovered from banana only while H. multicinctus was present on banana and nine weed species and P. goodeyi was present on banana and only two weed species, namely, Digitaria velutina and Eleusine indica , at a very low count compared to banana. No nematodes were recovered from Tagetes minuta , Cyperus esculentus , Senecio disfolius and Digitaria scalarum , indicating that these four weed species are non-hosts of banana nematodes. 422 The occurrence of burrowing nematodes Radopholus spp. on durian and coffee in Western Highland of Vietnam Chau N. N GUYEN 1 ; ¤ , Sergei A. S UBBOTIN 2 , Mehrdad M ADANI 3 , Phap Q. T RINH 1 and Maurice M OENS 3 1 Institute of Ecology and Biological Resources, NCST, 12 Hoang Quoc Viet Rd., Hanoi, Vietnam 2 Institute of Parasitology, RAS, Leninskii Prospect 33, Moscow, 177071 Russia 3 Agricultural Research Center, Burg. Van Gansberghelaan 96, 9820, Merelbeke, Belgium ¤ nchau@iebr.ncst.ac.vn Burrowing nematodes associated with durian ( Durio zi- betinus ), coffee ( Coffea spp :/ , banana ( Musa paradisiaca var. sapientum ), rambutan ( Nephelium lappacium ) and av- ocado ( Persae americana ) have been recently recorded in Western Highland Vietnam. The nematodes are widely distributed on durian orchards and coffee plantations;only a few specimens were extracted from root samples of banana, avocado and rambutan. In the infected regions, Radopholus was not detected on corn ( Zea mays ), black pepper ( Piper nigrum ), mango ( Mangifera indica ), citrus ( Citrus spp.), pineapple ( Ananas sativa ), sugarcane ( Sac- charum of cinarum ) and papaya ( Carica papaya ). Nema- todes caused decline and death of trees in many durian nursery gardens and newly replanted orchards. Nematode densities reached several thousands of individuals per g for root samples. Nematodes also induced some damage in coffee plantations( C. arabica and C. robusta ). Morpho- logical and morphometrical comparisons of all nematode stages revealed only slight differences between Radophu- lus populations from durian and coffee and rom R. simi- lis. However, the molecular analysis based on sequencing of ITS-rDNA showed substantial nucleotide differences Vol. 4(2), 2002 271</p>
<p>Distribution, population dynamics (383-443) between these Vietnamese populations and R. similis and supports their separate taxonomic status. 423 The frequency and diversity of the cyst and lesion nematodes on wheat in the Turkish Central Anatolian Plateau Julie N ICOL 1 ; ¤ , Roger R IVOAL 2 , Necmettin B OLAT 3 , Hussein A KTAS 4 , Hans-Joachim B RAUN 1 , Mohamed M ERGOUM 1 , Ali Faik Y ILDRIM 3 , Ahmet B AGCI 5 , Halil E LEKCIOGLU 6 and Amor Y AHYAOUI 7 1 International Wheat and Maize Improvement Center (CIMMYT),Wheat Program, P.O. Box 39, Emek, 06511, Ankara, Turkey 2 UMR INRA/ENSAR, Biologie des Organismes et des Populations appliquée à la Protection des Plantes (BiO3P), BP 35327, 35653 Le Rheu, France 3 ANADOLU Agricultural Research Institute, PK 17 26001, Eskisehir, Turkey 4 Plant Protection Institute, Ankara, Turkey 5 Bahri Dagdas MIKHAM, Konya, Turkey 6 Cukarova Universitesi, Adana, Turkey 7 International Centre Arid Research Dryland Agriculture (ICARDA), P.O. Box 5466, Aleppo, Syria ¤ jnicol@cgiar.org In June 2000 a survey was conducted on the Central Ana- tolian Plateau, the major winter wheat growing region of Turkey. The objective was to understand the distribu- tion of two economicallyimportant cereal nematodes, cyst ( Heterodera spp.) and lesion ( Pratylenchus spp.) Thirty soil and plant samples were collected around the milky dough stage from wheat sampled about every 50 km. Sev- enty two percent of the root samples and 83% of the soil samples contained cysts, and in approximately 40% of soil samples, one or both lesion nematodes were found ( P. thornei and/or P. neglectus ). Cereal cyst nematode was identi ed to species level using both traditional morphol- ogy and a RFLP PCR based molecular method. None of the samples contained the most common cereal cyst ne- matode documented, H. avenae . Instead, 40% of the sam- ples contained H. latipons , 32% H. lipjevi and 28% a mix of both species. Regarding species identi cation, in about 10% of the samples the molecular diagnostics did not align with the morphological assessment. Furthermore, 60% of samples contained root-rotting fungi ( Fusarium spp. and/or Bipolaris spp.). 424 First report of Meloidogyne partityla on pecan in Georgia Andrew P. N YCZEPIR 1 ; ¤ , Charles C. R EILLY 1 , Bruce W. W OOD 1 and Stephen H. T HOMAS 2 1 U.S. Department of Agriculture, ARS, Southeastern Fruit and Tree Nut Research Laboratory, Byron, GA 31008, USA 2 Department of Entomology, Plant Pathology, and Weed Science, New Mexico State University, Las Cruces, NM 88003, USA ¤ anyczepir@saa.ars.usda.gov Tree decline was observed in a commercial pecan orchard in Georgia in 2000. Affected trees exhibited dead branches in the upper canopy, stunted growth, and feeder roots with small galls and associated egg masses typical of root-knot nematode infection. All declining trees that were examined had root systems infected with Meloidogyne sp. Identi cation of this nematode was based on two procedures. First, in Georgia, females were removed from root galls of declining trees and identi ed by determining the esterase phenotype as compared to standard root-knot nematode species including M. partityla . Secondly, galled roots were sent to New Mexico State University in Las Cruces, where mitochondrial DNA from specimens was extracted and compared to standard root-knot nematode species. Specimens were identi ed as M. partityla at both locations. This is the rst report of M. partityla from Georgia, and the third report of this nematode outside of South Africa. Meloidogyne partityla may be endemic to North America and not South Africa. It is believed that this nematode entered South Africa on pecan rootstock imported from the USA between 1912 and 1940. Determining the distribution of M. partityla within the pecan-growing regions of Georgia and North America is warranted. 425 The occurrence and geographic distribution of Xiphinema and Xiphidorus species (Nematoda: Longidoridae) in Brazil Claudio M.G. O LIVEIRA 1 ; ¤ , Derek J.F. B ROWN 2 , Roy N EILSON 2 , Ailton R. M ONTEIRO 3 and Luiz C.C.B. F ERRAZ 3 1 Instituto Biológico, Caixa Postal 70, Campinas, SP, 13.001-970 Brazil; 2 Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK; 3 Universidade de São Paulo, Escola Superior de Agricultura ‘Luiz de 272 Nematology</p>
<p>Poster sessions Queiroz’, Caixa Postal 09, Piracicaba, SP, 13.418-900 Brazil; ¤ colive@scri.sari.ac.uk The occurrence and geographic distribution of Xiphinema and Xiphidorus species were investigated during a na- tional survey of 16 Brazilian states between 1999 and 2001. Eighty-two soil samples were collected from dif- ferent habitats, including crop plants, grassland, savanna (cerrado) and typical Amazonian forest vegetation. Four- teen Xiphinema species ( X. brasiliense, X. costaricense, X. elongatum, X. ensiculiferum, X. ifacolum, X. krugi, X. longicaudatum, X. paritaliae, X. vulgare, X. surina- mense, X. brevicolle and three distinct morphotypes of X. americanum sensu lato tentatively identi ed as repre- senting X. diffusum, X. oxycaudatum and X. peruvianum ) were found in all surveyed states. Also, Xiphidorus yepe- sara yepesara , X. yepesara parthenus , X. minor and X. balcarceanus were identi ed from two states; however, recognition of X. yepesara parthenus as a subspecies of X. yepesara requires con rmation. The most frequently occurring species were X. krugi (46%), X. brasiliense (22%) and X. vulgare (22%). Xiphinema longicaudatum and Xiphidorus balcarceanus constitute new records for Brazil. 426 Bursaphelenchus species found in maritime pine in Portugal Ana C ATARINA P ENAS 1 , Maria A NTONIA B RAVO 1 , Joana P IRES 1 and Manuel M OTA 2 1 Departamento de Protecção das Plantas, Estação Agronómica Nacional, INIA, Quinta do Marquês, 2784-505 Oeiras, Portugal; 2 NemaLab/ICAM, Departamento de Biologia, Universidade de Évora, 7000 Évora, Portugal; nemalab@uevora.pt In March 1999, the Pine Wood Nematode (PWN) Bursaphelenchus xylophilus (Steiner & Buhrer, 1934) Nickle 1970, was found associated with dead maritime pine ( Pinus pinaster Ait.) for the rst time in Portugal and in Europe. Of cial authorities implemented an intensive survey in the region where the nematode was found and then extended it to the rest of the country. As a result, this quarantine organism was con rmed to be con ned to a 30 km radius area in the Setúbal region, near Lisbon. During the survey other species of Bursaphelenchus were found associated with P. pinaster , such as B. mucronatus , B. leoni , B. tusciae , B. hofmanni , B. hellenicus, B. teratospicularis , B. hylobianum , B. sexdentati and B. pinophilus . The identi cation was based on observations of morphological characters under optical and scanning electronic microscopes. 427 Nematode assemblages from a polar arctic desert Vlada P ENEVA 1 ; ¤ , Stela L AZAROVA 1 and Olga M AKAROVA 2 1 Central Laboratory of General Ecology, 2 Gagarin Street, 1113 So a, Bulgaria; 2 Laboratory of Community Structure and Dynamics, Institute for Problems of Ecology and Fvolution, Leninsky Prospect 33, Moscow, Russia; ¤ vpeneva@ecolab.bas.bg Preliminary results are presented on the generic struc- ture and several ecological parameters of nematode as- semblages in relation to ve types of microhabitats from a polygonal polar desert on Bol’shevik Island, Sever- naya Zemlya Archipelago. Among 33 genera encoun- tered, more than half were common to the majority of mi- crohabitats (all or four types). Nematode abundance was high in Deschampsia borealis and black crust microhabi- tats (average 81 and 69 specimens/g) and low in bare soil (eight specimens/g). Bacterial feeders were the most di- verse and dominant trophic group (15 genera), followed by omnivorous and plant-feeding nematodes ( ve and six genera, respectively). Predatory and fungal-feeding ne- matodes were represented in low percentage. This gen- eral pattern differed only for assemblages from bare soils where trophic groups were almost equally distributed. Again, nematode communities of bare soils had the low- est diversity and generic richness. The rst gradient re- vealed by an ordination procedure was from nematode assemblages of higher plant vegetation and black crust, to these of moss communities. Along the second gradi- ent nematode communities of bare soils were separated as the most speci c group. The genera Acromoldavicus and Boreolaimus represent new geographical records. 428 Plant-parasitic nematodes associated with mango varieties on two rootstocks in Mara municipality of Zulia state, Venezuela O. Q UIJADA 1 , G. C ASTELLANO 1 , N. J IMÉNEZ 2 and E. B RICEÑO 2 1 Instituto Nacional de Investigaciones Agrícolas, INIA-Zulia, Apdo 1316, Maracaibo, Venezuela; 2 UCLA, Decanato de Agronomía Dpto. de Ciencias Biológicas postgrado de Vol. 4(2), 2002 273</p>
<p>Distribution, population dynamics (383-443) Fitopatología, Apdo 400, Barquisimeto, Estado Lara, Venezuela; biblio_zulia@impast.net.ve Parasitic nematodes on mango ( Mangifera indica L.) cvs Haden, Tommy Atkins, Irwin, Gleen, Keitt, Ford and Palmer, grafted on Sinamaica and Bocao root- stocks, were identi ed from 64 soil and root sam- ples taken at the Hortofruiticola Center in Zulia state. Nematodes were extracted using Oostenbrink and Baermann funnel equipment. The varieties grafted on Sinamaica rootstocks had Hoplolaimus, Trichodorus, Pratylenchus, Hemicriconemoides, Rotylenchus, Heli- cotylenchus, Xiphinema, Tylenchus and Meloidogyne. The varieties grafted on Bocao rootstock had Hoplolaimus, Helicotylenchus, Rotylenchus, Xiphinema, Trichodorus and Meloidogyne , with the most frequent genera as Ho- plolaimus, Hemicriconemoides and Rotylenchus. A brief description is reported and identi cation key proposed. 429 Plant-parasitic nematodes associated with papaya ( Carica papaya ) in different producing areas of the State of Bahia, Brazil Cecília Helena Silvino Prata R ITZINGER ¤ , Rogério R ITZINGER and Élio Jose A LVES Embrapa Mandioca e Fruticultura, Caixa postal, 007, Cruz das Almas, BA, Brazil ¤ cecilia@cnpmf.embrapa.br In the State of Bahia, papaya production ( Carica papaya ) is distributed in all microregions whereas Extremo Sul and Extremo Oeste have the major production. Although plant-parasitic nematodes are a great problem in papaya, there are no data on nematode occurrence and damage in papaya plantings in the State of Bahia. This work aimed to identify the occurrence of plant-parasitic nematodes by collecting soil samples in commercial plantings in the Extremo Sul of Bahia, as well as in Iaçu and in an experimental area of the Federal University of Bahia, in Cruz das Almas. The extraction of nematodes from soil was carried out by the sieving and centrifugation method, and from roots samples by the Baermann method. Plant-parasitic nematodes were reported considering the frequency and incidence for each homogeneous area. In general, Meloidogyne sp., Rotylenchulus sp.; Helicotylenchus sp., Criconemella sp., Tylenchus sp. and Pratylenchus sp. were present in all production areas. The largest diversity was observed in Porto Seguro and the largest frequency for all areas by Meloidogyne sp., Rotylenchulus sp. and Helicotylenchus sp. More detailed studies are suggested, as well as correlation studies of populationlevel with other soil diseases and damage level. 430 Specialities of zone geographic distribution of soil nematodes on the territory of Russia E.N. R OMANENKO -P OPOVA Institute of Geography and Institute of Global Climate and Ecology, Russian Academy of Sciences, Glebovskaya ul, 20B, Moscow, 107258, Russia The soil nematode fauna of different geographic regions of Russia (Karelia, Moscow and Voronezh regions and Kalmykia) were investigated during 1992-1997. The base of the nematode fauna of different soils of these regions was the orders Tylenchida, Dorylaimida and Rhabditida. The orders Enoplida and Chromadorida were characteristic of hydromorphic soils. The role and diversity of nematodes from the order Mononchida increased from north to south. The percentage of other nematode orders varies in different soils. The abundance of nematodes rises in latitude-zone row of soil types in sequence: podzol (Karelia); podzolic soils (Moscow region); chernozem soil (Voronezh region), and decreases signi cantly in chestnut soils of Kalmykia. The nematode fauna of intra- and azone soils of Karelia was less abundant than those of zone soils of that region but increases in comparison with the zone soils sequentially from north to south in other investigated regions. Thus, the nematode fauna of moist intra- and azone soils was six to ten times more than those of zone soils of Kalmykia. 431 Histological alterations in Caricaceae roots caused by a mixed population of Meloidogyne incognita Race 1 and Rotylenchulus reniformis Ligia Carolina R OSALES ¤ , Zoraida H. S UÁREZ and María Alejandra G ÓMEZ Instituto Nacional de Investigaciones Agrícolas, CENIAP, Protección Vegetal, Apdo 4653, Maracay 2101, Aragua, Venezuela ¤ carolinar@yahoo.com Histological alterations on Carica papaya , Vasconcellea cauli ora and V. pubescens inoculated with a mixed population of Meloidogyne incognita Race 1 and Rotylenchulusreniformis were studied. Segments of roots from each species were xed in Craff III and dehydrated in a tertiary butyl alcohol series, embedded in paraf n, cut in 15 ¹ m sections and stained with quadruple Triarch’s 274 Nematology</p>
<p>Poster sessions stain modi ed by Suárez et al . All species of Caricaceae showed giant cells, nuclei and nucleoli and egg mass typical of Meloidogyne . Furthermore, the same species of plant showed also the vascular parenchyma cells forming a syncytium induced by Rotylenchulus . These cells are hypertrophied with granular cytoplasm, enlarged nuclei and prominent nucleoli. This research allowed demonstration that both nematode species can establish their feeding site in the same plant. 432 Meloidogyne incognita races distinguished by sweet potato differential cultivars and their distribution in the Kyushu Okinawa region, Japan Zen-ichi S ANO and H. I WAHORI National Agricultural Research Center for Kyushu Okinawa Region, Nishigoshi, Kumamoto 861-1192, Japan To use cultivars of sweet potato with resistance to Meloidogyne incognita effectively, occurrence and distribution of resistance breaking races were examined. Four populations of M. incognita were collected from different elds and inoculated to 24 major sweet potato cultivars. Based on the reproduction rates of these nematode populations, ve differential cultivars, Norin No. 1, Norin No. 2, Tanegashima-murasaki 7, Elegant Summer and J-red were selected. A total of 97 M. incognita populations were collected from sweet potato elds in central to southern Kyushu and Okinawa. Seven races were identi ed from these populations. In Kumamoto prefecture central Kyushu, race SP1 that reproduces only on Norin No. 1 represented 81% of 26 examined populations. In Miyazaki and Kagoshima prefecture southern Kyushu, SP 2 that reproduces on both Norin No. 1 and Norin No. 2 was predominant. In Okinawa, SP 4 that reproduces on four of the differential hosts but not on J-Red represented more than half of the 12 examined populations. 433 Association of Meloidogyne konaensis and the nutritional status of Coffea arabica D.P. S CHMITT 1 ; ¤ , D. H URCHANIK 1 , N.V. H UE 2 and B.S. S IPES 1 1 University of Hawaii, PEPS, 3190 Maile Way, Honolulu, HI 9682, USA; 2 University of Hawaii, TPPS, 1910 East-West Road, Honolulu, HI 96822, USA; ¤ schmitt@hawaii.edu The relationship of population densities of Meloidogyne konaensis to nutritionalstatus of roots and leaves of coffee cv. Typica in a naturally infested commercial eld in the Kona district on the island of Hawaii was assessed. The numbers of M. konaensis and the concentration of K C Ca C Mg in the coffee roots were inversely related. Other inverse relationships were between the numbers of M. konaensis and concentrations of Mg (roots), Cu (roots and leaves) and Al (roots). Even though concentrations of P, K, Mg, K C Ca C Mg, Mn, and Zn increased in soil between February (dry season) and May (wet season), concentrations of P, K, Mg, K C Ca C Mg, Cu, B decreased in the coffee roots, and Zn and Al content decreased in the coffee leaves. Nematodes plus nutrient de ciencies and imbalances in the coffee trees are causing coffee decline. 434 Plant-parasitic nematodes associated with Ammophila arenaria (L.) Link in Portuguese coastal sand dunes Catarina S CHRECK R EIS 1 ; ¤ , Helena F REITAS 1 and Wim VAN DER P UTTEN 2 1 IMAR, Departamento de Botânica, Universidade de Coimbra, 3000 Coimbra, Portugal 2 NIOO, Dept of Multitrophic Interactions, Boterhoeksestraat, 48, P.O. Box 40, 6666 ZG, Heteren, The Netherlands c_schreck_reis@mail.pt Portuguese sand dunes extend for 450 km, more than half of the coastline. Ammophila arenaria (marram grass) is the dominant, and eventually the only, natural plant species in mobile dunes. The unmatched contribution of A. arenaria to sand xation and dune formation is related to its extensive root and rhizome system and with its vertical growth, stimulated by sand deposition. In stabilised dunes, where no sand accumulation occurs, this species declines in vigour and growth. This behaviour, named ‘the Ammophila problem’, has been largely studied from nutrition, ageing, genetic differentiation to interspeci c competition, among others, but is still unanswered. Recent studies relate this degeneration to the presence of pathogenic soil organisms, like parasitic nematodes, while others believe that the cause is the absence of mycorrhizal fungi. In the presentation, we provide an overview of plant-parasitic nematodes present in the roots and rhizospheric soil of A. arenaria in two dune systems of the Portuguese coast. The data shows a higher number and diversity of nematodes in the north population,where plants are more vigorous, althoughonly two of the three species known to parasitise A. arenaria Vol. 4(2), 2002 275</p>
<p>Distribution, population dynamics (383-443) are present. Some highlight plans for further research will also be presented. 435 Reaction of passion fruit genotypes to root-knot nematode, Meloidogyne javanica R.D. S HARMA , N.T.V. J UNQUEI RA and A.C. G OMES Embrapa Cerrados, Caixa Postal 08223, CEP 73301-970, Planaltina, DF, Brazil Considering the widespread distribution and the losses the root-knot nematode, Meloidogyne javanica , causes to different crops in the Cerrado region of Brazil, the reaction of 11 genotypes (EC-2-O Hybrido, Vermelhinho, IAC-comp. Hybrido, MSC, Roxo Australiano, Seleção DF, Longão PR-2, Vermelhão, Redondão PR-1, Roxo Fiji e Itaquiraí) of passionfruit ( Passi ora edulis f . avicarpa ), and P. edulis ) were evaluated under glasshouse conditions. Five 17-day old seedlings of each genotype were inoculated with initial inoculum of approximately 5250 eggs and second stage juveniles per plant per pot containing one kg of soil, and an equal number of plants were maintained as uninoculated checks. Tomato variety Santa Cruz was included as a susceptible check. Eighty days after nematode inoculation, indices of root-knot galls, indices of egg masses, nal population densities of nematodes in soil and roots, and the percentage increase or decrease in dry vine weights of the inoculated plants were compared with the uninoculated controls. The gall index for different genotypes varied from 4.6 to 5.0 and the egg mass index from 0 to 2 and the reproduction factor from 0.001 to 0.061. The reproduction factor for susceptible tomato varied from 16.95 to 39.48. All genotypes tested were highly resistant to M. javanica . 436 Detection of entomopathogenic nematodes and their possible use under IPM in Pakistan Manzoor H. S OOMR 1 , F. S HAHINA , M.A. M AQBOOL 2 and Iftikhar A HMAD 1 1 National IPM Programme, National Agricultural Research Centre, Islamabad, Pakistan; 2 National Nematological Research Centre, University of Karachi, Karachi, Pakistan In Pakistan, studies on biology, taxonomy and ef cacy of entomopathogenic nematodes (EPN) were initiated in 1996. Since then, during extensive surveys, over 1000 soil samples have been collected from diverse habitats of Pakistan with emphasis on Sindh Province. Nematodes were collected using the Galleria mellonella soil trap method. Three isolates of Steinernema and 59 of Heterorhabditis were detected, of which 22 isolates were identi ed as H. indica. Out of the identi ed EPN, two are new species; one has been described as Steinernema pakistanense (Shahina et al ., 2001), while the other Steinernema species is in the process of description. Pathogenicity of new indigenous EPN, S. pakistanensis, was tested against seven insect pests of common occurrence and agricultural importance under laboratory conditions and con rmed on Helicoverpa armigera, Earias insulana, E. vittella, Papillio demoleus, Leucinodes orbonalis, Etiella zinkenella and Hollotrichia consanguinea . Mortality was higher (up to 100%) on early stages of insect larvae ( H. armigera ) as compared to fourth and fth stage larvae. Search for more indigenous EPN is continuing and, under the National IPM Programme, eld-testing of promising species will be undertaken during the year 2002. The farmers will be trained for conservation of natural enemies including EPN through the farmer eld school (FFS) approach particularly for the cotton crop, which receives the largest amount (60%) of pesticides in Pakistan. 437 Association of plant-parasitic nematodes of the family Longidoridae with fruit crops in Poland Adam S ZCZYGIEL Fruit Experiment Station, Brzezna, 33-386 Podegrodzie, Poland instytut.szczygiel@brzezna.pl In 453 soil samples, collected from root vicinity of apple, pear, plum, peach, sour and sweet cherry, walnut, hazelnut, black and red currant, gooseberry and raspberry, six species of Xiphinema and eight species of Longidorus were found. Equally common Xiphinema species were X. diversicaudatum , X. brevicolle and X. vuittenezi . Another three species were found only once or twice. The most common Longidorus species was elongatus , followed by L. attenuatus and less frequently L. euonymus and L. leptocephalus . The other four species occurred sporadically. Almost all species showed preference for some hosts and some of them also for soil type and soil pH. Xiphinema diversicaudatum preferred black currant, pear and sour cherry, Xiphinema brevicolle – walnut and sour cherry, while Xiphinema vuittenezi preferred raspberry and red currant. Longidorus elongatus was commonly associated with pear, peach, sour cherry, walnut, gooseberry and plum. Xiphinema diversicaudatum showed preference for heavy soils, 276 Nematology</p>
<p>Poster sessions while X iphinema brevicolle , X iphinema vuittenezi and most Longidorus species preferred light sandy soils; X. diversicaudatum and brevicolle preferred soil pH 4.5-6.5 while vuittenezi and Longidorus elongatus did not show preference for soil pH, andt other Longidorus species preferred soils of pH 5.6-6.5. 438 Elaboration of database of nematodes detected in imported plant germplasm in Brazil in 1981 to 2001 R.C.V. T ENENTE 1 , V.R.V. R ISSOLI 2 , L. P ALHARES 2 and F.G. A LVARENGA 2 ; ¤ 1 EMBRAPA, Recursos Genéticos e Biotecnologia, P.O. Box 2372 (70849-970) Brasília, DF, Brazil 2 Universidade Católica de Brasília, QS 07-Lote 01 (72022-900) Taguatinga Sul, DF, Brazil ¤ falvaremga@yahoo.com.br Plant introduction has been one of the most effective actions for agricultural development in the tropics. Coffee and soybean in Brazil, banana in South and Central America, sugarcane in South America and Caribbean and grass pastures in Latin America, are good examples of successful introductions. But the germplasm movement involves the risks of introduction of exotic pests that are sometimes carried by seeds and propagated vegetative materials. EMBRAPA’s post- entry quarantine is inspecting against pests, including nematodes, all the plant material that has been introduced into Brazil for research purposes. In this context, the nematologicallaboratory did the inspection and registered all the nematodes found associated with germplasm from different species of plant and different countries. Now, a computational database is under construction to make extremely fast, easy and more ef cient the recovering these data. Other researchers that need to access such data for their work can contact the Embrapa Genetic Resources and BiotechnologyCenter and we will help them with the information that is available. 439 Characterisation of Meloidogyne incognita reproduction on yellow nutsedge, purple nutsedge and chile pepper Stephen H. T HOMAS 1 , Jacqueline F UCHS 1 , Jill S CHROEDER 1 and Leigh W. M URRAY 2 1 Department of Entomology, Plant Pathology, and Weed Science, Box 30003 MSC 3BE 2 University Statistics Center, Box 30001 MSC 3CQ, New Mexico State University, Las Cruces, NM, USA The objective of this research was to determine if either yellow or purple nutsedge altered Meloidogyne incognita reproduction compared to susceptible chile peppers. Greenhouse experiments were conducted in 2000 and 2001, with 240 pots planted with chile pepper ( Capsicum annuum ), yellow nutsedge ( Cyperus esculentus D YNS), purple nutsedge ( C. rotundus D PNS), chile C YNS, or chile C PNS. Six pots from each treatment were harvested at 3-4 day intervals from 21 through 45 days after inoculation with 5000 eggs of M. incognita . Root systems (chile) or roots, rhizomes and tubers (YNS, PNS) were divided and eggs extracted from half. Egg masses on the remaining half were stained with phloxine B. The number of egg masses per root, eggs per egg mass, and total egg production per root system was measured for each plant and sample date. Chile supported much greater nematode reproduction than YNS or PNS, producing twice as many egg masses per gram of root and twice as many eggs per egg mass. Competition between chile and either nutsedge had no effect on egg mass density or numbers of eggs per egg mass in any host. Reproduction occurred on roots but not rhizomes or tubers of either nutsedge. 440 Weeds as hosts to root lesion nematodes ( Pratylenchus neglectus and P. thornei ) Vivien A. V ANSTONE 1 ; ¤ , Michelle H. R USS 1 ; 2 and Sharyn P. T AYLOR 1 University of Adelaide, Department of Plant Science, pmb 1, Glen Osmond, 5064, South Australia, Australia 2 South Australian Research and Development Institute, GPO Box 397, Adelaide, 5001, South Australia, Australia ¤ vivien.vanstone@adelaide.edu.au Pratylenchus neglectus and P. thornei occur throughout the broadacre, dryland cereal cropping zone of south- eastern Australia. Hosting ability of nine monocotyledon (grass) and 20 dicotyledon (broad-leaf) weed species common to cropping rotations was tested in the glasshouse. Nematode multiplication rates ( Pf/Pi ) were assessed relative to wheat cv. Machete (susceptible) and triticale cv. Abacus (resistant). Weeds were classi ed as good (susceptible), poor (moderate) or non (resistant) hosts. Grasses differed in susceptibility to P. neglectus compared to P. thornei . For each nematode, two grass species were susceptible, three moderate and four resistant. Multiplication rates on broad-leaf weeds were lower than on the grasses. Six broad-leaf species were Vol. 4(2), 2002 277</p>
<p>Distribution, population dynamics (383-443) susceptible to P. neglectus and 14 resistant; one was moderate for P. thornei and 19 resistant. Growth of susceptible weeds will allow increase and/or persistence of nematodes in cropping soils, compromising use of management strategies (particularly rotation with resistant crops) employed by growers to reduce nematode densities and alleviate crop losses. Monitoring susceptible weeds in crops, pastures and fallows will aid nematode management and control decisions. 441 PWN-CD: information database for the pinewood nematode Bursaphelenchus xylophilus P. V IEIRA ¤ and M. M OTA NemaLab – ICAM/Departamento de Biologia, Universidade de Évora, Portugal ¤ pvieira@uevora.pt The main objective of this project is to develop an information database with the inclusion of text (research articles, keys, bibliography), images (jpeg les), video clips (mpeg les), in order to collect in one physical support (CD-ROM) all relevant information related to the pine wood nematode (PWN), Bursaphelenchus xylophilus . The rst volume presented here covers the taxonomy of the genus Bursaphelenchus . All major papers with the original species descriptions have been scanned in ‘pdf’ format. An updated and broad bibliography has been included. In the future, a taxonomical key, based on classical dicotomous keys but with a better and more intuitive presentation, will be developed. The nal product is PC and Mac compatible. Future editions/updates will be developed, in particular related to the nematode vectors and the bioecology of the nematode-vector-plant. Ultimately, researchers, technicians and political decision-makers will have at their disposal a practical and readily available source of information on this extremely important pest and pathogen. 442 A checklist of nematodes from plant and soil in Portugal P. V IEIRA ¤ , M. M OTA and C. C OSTA ICAM, Departamento de Biologia, Universidade de Évora, 7000 Évora, Portugal ¤ pvieira@uevora.pt In southern Portugal the grassland ecosystem known as ‘montado’ has a particular ecological and social importance due to its extensive area and also because it is where cork and holm oak grow. Integrated in a PAMAF project a study has been conducted to evaluate changes caused by some agricultural practices and its effects on the nematode communities associated in this type of ecosystem. Nematode diversity in grasslands is usually high. Nematode identi cation of the specimens found in the ‘montado’ of the Evora region (southern Portugal) is in progress, and some represent new genera/species reports for Portugal. Related to the taxonomic work, a compilation of all plant and soil nematode genera/ species (non animal-parasitic)and related references from Portugal will be presented. 443 Plant-parasitic nematodes of maize ( Zea mays L.) in low input agriculture in Kenya J.W. W ACEKE 1 ; ¤ , O.J. A RIM 1 , S.W. W AUDO 1 and J.W. K IMENJU 2 1 Department of Botany, Kenyatta University, P.O. Box 43844, Nairobi, Kenya; 2 Department of Crop Protection, University of Nairobi, P.O. Box 29053, Nairobi, Kenya; ¤ wacewanj@yahoo.com Different farming systems existing in Kenya have varied cultivation practices supporting diverse nematode genera and species. A survey conducted during the short rains in eight localities within two districts in Central Highlands of Kenya identi ed 12 genera of plant parasitic nematodes associated with maize. Both soil and root samples were collected from the rhizospere of maize at the tasseling stage and assayed for nematodes. Main nematode genera recovered from soil samples in decreasing order of prominence were Pratylenchus , Meloidogyne , Paratylenchus, Tylenchus , Ditylenchus, Heterodera and Scutellonema spp. The main nematode genera found in maize roots in order of decreasing prominence were Pratylenchus , Hemicycliophora , Tylenchorhynchus , Tylenchus , Ditylenchus , Paratylenchus and Meloidogyne spp. In both root and maize samples, Pratylenchus was the most predominant genus occurring in 100 and 96% of soil and maize root samples, respectively. A coef cient of determination ( r 2 D 0 : 83 / was obtained between number of Pratylenchus spp. recovered from the soil and that from the root. Soil samples collected in 63% of the localities had above critical infestation level of two Pratylenchus spp./cm 3 of soil. Root necrosis differed signi cantly with locality 7 showing the highest root necrosis. 278 Nematology</p>
<p>Poster sessions 444 Biofumigation tests: changes in the population of Globodera spp. and in the enzymatic activity of soils added with organic amendments B. de A YMERICH V ADILLO ¤ and J. L OPEZ R OBLES Edafologia y Quimica Agricola, Facultad de Ciencias, Universidad de Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain ¤ ceibe43@hotmail.com Small biofumigation tests were carried out in pots with soil naturally infected by Globodera spp., using different amendments as fumigants: seaweed of the genus Gelidium , remains from gardening (grass, dry leaves) and potato peel ( Solanumtuberosum ). Soil without amendment was used as control. The treated soil was watered, sealed with black plastic, and kept under controlled conditions of humidity and temperature for 30 days. The value of the ratio nal/initial population of the Globodera spp. was calculated, as was the variation in ureasic, phosphatasic and deshydrogenasic activity at the end of the treatment. The nematode population fell by 34% for the soil amended with Gelidium , 56% for the samples with grass and potato peel, compared with 5% for the control. This fall in the population is caused by the liberation of nematicide substances by the amendments and an increase in the chitinolic micro ora and total edaphic biomass, re ected in the increase in enzymatic activity of the amended soil in relation to the control. 445 Poultry litter for the management of root-knot nematode on pumpkin in Puerto Rico José A. C HAVARRÍA -C ARVAJAL 1 ; ¤ , Edwin A CEVEDO 2 , Carlos F LORES 3 , Nidia V YCENTE 1 , Luis S ILVA -N EGRÓN 1 and Evelyn R OSA 1 1 Department of Crop Protection, Mayagüez Campus, University of Puerto Rico, P.O. Box 9030, Mayagüez, 00681-9030, Puerto Rico 2 Department of Agronomy and Soils 3 Department of Horticulture, Isabela Substation, Isabela, 00662, Puerto Rico ¤ jachavar@hotmail.com Accumulation of solid wastes from human activities and agro-industries is a serious problem in Puerto Rico that represents an environment hazard and leads to signi - cant pollution of soils, waterways, and lakes. The proper use and disposal of these materials in agricultural soils, through their application for management of phytonema- todes, could be very useful for nding solutions to this problem. Poultry litter was evaluated under eld condi- tions for the management of Meloidogyne incognita on pumpkin ( Cucurbita moschata ) cv. Soler. The amend- ment was applied to a root-knot-infested soil at rates of 0, 7.3 and 14.5 kg/plant; in addition, a treatment with phenamiphos at 1.5 gai./plant, was included to determine the effectiveness of the amendment. The experiment was conducted during two cropping seasons. Final soil and root populations of root-knot nematode were determined during each cropping season. Results showed that poultry litter reduced population densities of M. incognita , and improved plant development, and crop yield. 446 Evaluation of the ef cacy of mixing tops of forage grasses with soil to control Meloidogyne incognita and Heterodera glycines C.R. D IAS -A RIEIRA and S. F ERRAZ Universidade Federal de Viçosa, Depto de Fitopatologia, Viçosa, MG, Brazil, 36571-000 silamar@mail.ufv.br To control Meloidogyne incognita and Heterodera glycines , Brachiaria brizantha, B. decumbens, Panicum maximum cv. Guiné, Andropogon gayanus cv. Planaltina, and soybean tops were mixed one per se with soil and left there to deteriorate. In trial 1, 8 g of the grass tops were each mixed into soil in 2.5 l pots, and 30 days later one indicator tomato or soybean seedling was established per pot. Meloidogyne incognita eggs and egg masses and H. glycines females were counted respectively 45 and 30 days later. In trial 2, infested pots were planted with the grass seedlings: half were cultivated for 30 days and their tops mixed with the soil; in the other half cultivation lasted 30 more days and evaluation was done as indicated. Results in trial 1 showed no treatment effects on nematodes survival. In trial 2, only 37 females of H. glycines were found per root system of B. decumbens while 689 and 547 were counted in soybean roots cultivated for 60 and 30 days, respectively. Andropogon gayanus cv. Planaltina was the only grass among all tested to allow M. incognita to reproduce. But overall there was no effect of mixing any of these forage grasses with soil on the ef ciency of the rotation in controlling M. incognita and H.glycines. 447 Effect of repeated use of organic amendments and biofumigation plus solarisation on glasshouse pepper nematodes in the southeast of Spain Vol. 4(2), 2002 279</p>
<p>Organic amendments (444-448) M.M. G UERRERO 1 , C. R OS 2 , P. G UIRAO 2 , A. L ACASA 1 ; ¤ , M.A. M ARTÍNEZ 1 , M.C. M ARTÍNEZ 1 , N. B ARCELÓ 1 , M. O NCINA 1 , A. C ANO 1 and A. G ONZÁLEZ 1 Protección Vegetal, Centro de Investigación y Desarrollo Agroalimentario, CAAMA, C/Mayor s/n, 30.150 La Alberca, Murcia, Spain 2 FECOAM – Consejería de Agricultura, Agua y Medio Ambiente. C/Caballero, 13, 30.002 Murcia, Spain ¤ Alfredo.Lacasa@carm.es When methyl bromide (MB) is not used for soil disinfection, Meloidogyne incognita becomes one of the main soil-borne pathogens in the southeast of Spain (Murcia and south of Alicante). Nematode incidence after several organic amendments (7 kg/m 2 fresh sheep manure (FSM) C 3 kg/m 2 chicken manure; FSM at 7 kg/m 2 C 0 : 5 kg/m 2 soybean our; EFO at 7 kg/m 2 of C urea at 25 kg/m 2 / was compared with MB treatments in commercial and experimental glasshouses. The effect of the reiterated use of FSM and chicken manure was also studied. The three amendments had root-knot index and M. incognita incidence similar to MB treatments. However, marketable yield was signi cantly lower for urea (8.1 kg/m 2 / and chicken manure (8.6 kg/m 2 / than for soybean our (9.6 kg/m 2 / or MB (9.7 kg/m 2 / . Marketable yield of 1st year biofumigation-solarisation treatments was signi cantly lower than those of the 2nd (11.3 kg/m 2 / and 3rd year (11.2 kg/m 2 / and that of MB treatments (11.2 kg/m 2 / . Similar response was observed for the root-knot index (1st year, 4.5; 2nd year, 1.8; 3rd year, 1.3; MB,1.5) and the percentage of infested plants (1st year, 90.0%; 2nd year, 43.3%; 3rd year, 40.0%; and MB, 36.7%). 448 Nematode-suppressive effects of composts against Meloidogyne javanica on tomato Yuji O KA 1 ; ¤ and Uri Y ERMIYAHU 2 1 Division of Nematology 2 Soil Chemistry and Plant Nutrition, Gilat Research Center, M.P. Negev 85280, Israel ¤ okayuji@netvision.net.il Suppressive effects of two composts, cattle manure compost (CMC) and grape marc compost (GMC), on the root-knot nematode Meloidogyne javanica were tested in pot and in vitro experiments. No root-galls were found on tomato roots grown in soils containing 10 or 25% (v/v) CMC, and very few were found on those grown in soil containing 50% GMC. Signi cant reductions in galling index were also found in tomato plants grown in soils containing smaller concentrations of this compost. Chemical analysis of the composts and leachates from the soils showed that the CMC contained higher concentrations of N–NH 4 and higher EC values than the GMC, while the latter had higher N– NO 3 concentration. The water extract of the CMC showed high nematicidal activity to the nematode juveniles and less activity toward the eggs in vitro . The extract of the GMC showed weaker nematicidal activity to the juveniles and eggs. Washing composted soils with excess water before nematode inoculation and tomato planting led to better plant growth, but the nematode-suppressive effect was lowered. These results suggest that high nitrogen concentrations, especially N–NH 4 , and high EC values contribute to the nematode suppressiveness of the composts. 280 Nematology</p>
<p>Poster sessions 449 Assessment of DiTera to control plant-parasitic nematodes in vineyards in Chile Erwin A BALLAY ¤ and Andrea R IVEROS Facultad de Ciencias Agronómicas, Universidad de Chile, Casilla 1004, Santiago, Chile ¤ eaballay@uchile.cl During the 1999/2000 and 2000/2001 seasons, trials were carried out to evaluate the performance of the biological nematicide DiTera for the control of plant-parasitic nematodes affecting grapes, Vitis vinifera L., mainly Xiphinema index , X. americanum s.l. and Meloidogyne spp. Trials were carried out in the central region on vineyards for wine production, and for table grape production in a northern region of Chile. Grape varieties include Sauvignon Blanc, Cabernet Sauvignon and Thompson Seedless, respectively. DiTera was applied through a drip irrigation system at the rate of 40 l/ha at the beginning of spring root ushing and results were compared with a chemical standard and an untreated control. The effect of the treatments was assessed taking into account variations in number of nematodes per 250 cm 3 of soil, ( Pf/pi ), and also pruning weight. The nal results showed no statistical differences between the chemical standard and the DiTera treatments; however with respect to the untreated check, signi cant differences ( P D 0 : 05 / were noted, with control percentages between 77.4 and 91.5% at 30 days after applications. Yield and pruning weight also were signi cantly different ( P D 0 : 05 / in respect to the untreated plants. DiTera offers a new biorational option for control of nematode populations on grapes in Chile. 450 The toxic and the antagonistic effects of marine algal natural products on the embryonic development, juvenile development, and survival of nematodes Fawzia A BDEL -R AHMAN ¤ and Rohaiah S ALAH Biology Department, Texas Southern University, Houston, Texas 77004, USA ¤ abdelrahman_fh@tsu.edu The nematicidal activity of the methanol extracts of ten species of marine brown algae collected from the Red Sea coast were tested against different nematode species, including some free-living and plant-parasitic species. The test was conducted on the adult stages of the free-living nematodes, the adults and/or the juveniles of the parasitic species, as well as the egg-masses of the plant-parasitic species. The results revealed that there are recognisable nematicidal potentials of the tested algal extracts. Some of the tested extracts caused more than 90% mortality of the tested nematodes. The egg-hatching test, which was conducted on the plant-parasitic species only, proved that some algal extracts were able to prevent or disrupt the embryonic-development of the eggs in the tested nematode species. 451 The fungicide effect of the biological nematicide ‘Novibiotec 7996’ Mouldi M. B’ CHIR ¤ and Youssouf R AISSY Research Centre Al Rumais, P.O. Box 150, P.C. 328, Sultanate of Oman ¤ mouldi_bchir@yahoo.com Novibiotec 7996 was registered in Tunisia as a biological nematicide ovicide, ef cient in different nematode species control. It was tested in vitro and under plastic shelters against Pythium sp. associated with cucumber crops, and in open eld conditions on citrus and mango orchards infested, respectively, with Fusarium , Lasiodiplodia and Ceratocystis sp. in the sultanate of Oman. The Novibiotec 7996 comparative mode of action on nematode eggs and fungi organs will be presented and discussed. 452 In vitro pathogenicity of Monacrosporium robustum to Rotylenchulus reniformis Eduardo Roberto DE A. B ERNARDO and Jaime M. DOS S ANTOS ¤ UNESP/Faculdade de Ciências Agrárias e Veterinárias, Via de Acesso Prof. Paulo Donato Castellane s/n, 14884.900 Jaboticabal, SP, Brazil ¤ jm.santos@fcav.unesp.br The reniform nematode ( Rotylenchus reniformis ) is an important pathogen of many of the most important Brazilian crops such as soybean, cotton, beans, cowpea, passi ora, papaya, tomato, lettuce, among others. The successful biological control of pests in the upper parts of the plants and the environmental concern about the continuous use of nematicides have the effect of promoting the interest in biological control of nematodes, increasing considerably the economic potential of this activity. Among the nematophagous fungi with potential for commercial utilisation as agents of biological control of nematodes are the species of Monacrosporium. In this study, the predatory Vol. 4(2), 2002 281</p>
<p>Biological control (449-488) capacity of Monacrosporium robustum to the reniform nematode ( Rotylenchulus reniformis ) was evaluated in vitro . Concentrated suspension of J2, J3, J4, males and young females were transferred to the cultures of the fungus in Petri dishes with 2% water-agar and incubated at 26 o C in the dark. In periods of 24, 48 and 72 h after that it was observed that the percentage of captured nematodes were, respectively, 81.3, 99.87 and 100%. The adhesive branches as the capture structure of the fungus and captured nematodes were also documented by scanning electron microscopy. 453 Selection and diversity of Pasteuria penetrans isolates in relation to Meloidogyne spp. from coffee Regina M.D.G. C ARNEIRO ¤ , Myrian T IGANO , Camila L OPES J ORGE and Ana Cristina O LIVEIRA T EIXEIRA EMBRAPA Recursos Genéticos e Biotecnologia, CP. 02372, 70849-970, Brasília, DF, Brazil ¤ recar@cenargen.embrapa.br Pasteuria penetrans isolates from different geographical areas were tested for the ability of endospores to attach to second-stage juveniles and to colonise females of different populationsof Meloidogyne spp. from coffee and other crops. Our results con rm that spore attachment test cannot be used as the only criteria for screening for the ef ciency of the bacterial isolate against nematodes. The percentage of females infected with endospores and the endospore concentration/ml in 100 females were the best approaches for screening the highly aggressive isolates. Using these parameters, it was possible to select one isolate Pp12 for the three populations of M. paranaensis and the isolate Pp10 for the four races of M. incognita from coffee. For the other species M. hapla , M. exigua , M. graminicola and M. mayaguensis , the isolates were not compatible. In this study, there was clear evidence that the greatest parasitism occurred when the isolates of P. penetrans were exposed to species of Meloidogyne genetically close to those from which the bacteria populations were originally isolated. RAPD analysis was applied to ngerprint the genomes of P. penetrans isolates. Twenty 10-mer oligonucleotide primers of arbitrary sequence were used on this study. A high level of homogeneity was observed among the isolates. 454 Distribution of Pasteuria spp. associated with plant-parasitic nematodes in Korea Myoung Rae C HO 1 ; ¤ , Chun Keun L IM 2 , Heung Yong J EON 1 , Yong Moon C HOI 1 and Myoung Soon Y IEM 1 1 Division of Horticultural Environment, National Horticultural Research Institute, Suwon 441-440, Korea 2 Department of Agricultural Biology, Kangwon National University, Chunchon 200-701, Korea ¤ mrchook@rda.go.kr A survey was conducted on the distribution of Pas- teuria spp. associated with plant-parasitic nematodes in glasshouses in Korea from 1996 to 2000. Among the 372 soil samples assayed, 20 samples had plant-parasitic ne- matodes with Pasteuria spp. endospores attached. Ne- matodes found with Pasteuria endospores attached, host plants, and their localities were: Meloidogyne spp. on ori- ental melon at Sungju, Cheju, and Yeoju; Helicotylenchus sp. on white potato and carrot at Cheju; Meloidogyne sp. on soybean at Cheju; Heterodera sp. on unknown host plant at Chuju; and Aphelenchus sp. on garlic and radish at Cheju. Morphological characteristics of endospores from Meloidogyne spp. observed under electron microscope were the same as the previous descriptions of Pasteuria penetrans . 455 Biology and ultrastructure of a novel bacterial parasite of nematodes Aurelio C IANCIO 1 ; ¤ , Michelle C ERMOLA 2 , Renée F AVRE 2 and Gaetano G RASSO 3 1 Istituto per la Protezione delle Piante, Consiglio Nazionale delle Ricerche, Via Amendola 165/A, 70126 Bari, Italy 2 Istituto di Genetica Buzzati Traverso, Consiglio Nazionale delle Ricerche, Via G. Marconi 10, 80125, Naples, Italy 3 CSATA, Valenzano, Bari, Italy ¤ ciancio@area.ba.cnr.it A novel gram-negative bacterial parasite of free-living and plant parasitic nematodes was discovered in southern Italy. The bacterium is a septate rod with a unique shape resulting from the attening of both cell ends. It attacks vermiform stages producing a lethal disease. Parasitised nematodes may be observed easily at low magni cation because of the creamy-yellow colour they assume. After adhering to the host, the bacterium eventually penetrates its body, giving rise to a multiplicative phase spreading the infection and lling the whole nematode body with cells. The bacterial cells are released at nematode death and cadaver decomposition, infecting new hosts in the soil through direct contact and cuticle adhesion. Atomic force microscopy (AFM) ultrastructural data of live cells 282 Nematology</p>
<p>Poster sessions showed that the bacterium is covered by an adhesive matrix responsible for attachment. SEM and TEM were used to investigate the bacterium ultrastructure, and showed elongated cells measuring 4-5 £ 0.5 ¹ m. Attempts to culture the bacterium on common nutritive media failed. The pathogen was discovered in association with four distinct Meloidogyne spp. populations in southern Italy, but it was also observed in free-living Cephalobidae. The bacterium appears to be a novel invertebrate pathogen and will probably represent a further tool in nematode biological management. 456 Attachment tests of Pasteuria penetrans to clonal lines of Meloidogyne incognita Keith G. D AVIES ¤ and Rosa H. M ANZANILLA -L ÓPEZ Nematode Interactions Unit, IACR Rothamsted, Harpenden, Hertfordshire, AL5 2JQ, UK ¤ keith.davies@bbsrc.ac.uk Two single egg mass lines of Meloidogyne incognita were developed and from each of these lines freshly hatched second-stage juveniles (J2) were collected from three individual egg masses. Three separate replicates of 20 individual J2 from each egg mass were exposed to endospores of a population of Pasteuria penetrans originally isolated from a population of Meloidogyne javanica and the endospores adhering to each J2 were counted. One population of M. incognita became encumbered with between nine to over 100 endospores per J2 while in the other population this ranged from zero to less than 70 endospores per J2. The distribution of the numbers of endospores attaching to individual J2 was therefore very different, and in one population of M. incognita the numbers of endospores were highly skewed with the majority of J2 having fewer than ten endospores and one or two J2 having more than 30. The experiment was repeated and similar results were obtained.The results will be discussed in relation to clonal variation and their implications. 457 Attachment tests of Pasteuria penetrans to clonal lines of Meloidogyne incognita Keith G. D AVIES ¤ and Rosa H. M ANZANILLA -L ÓPEZ Nematode Interactions Unit, IACR Rothamsted, Harpenden, Hertfordshire, AL5 2JQ, UK ¤ keith.davies@bbsrc.ac.uk Two single egg mass lines of Meloidogyne incognita were developed and from each of these lines freshly hatched second-stage juveniles (J2) were collected from three individual egg masses. Three separate replicates of 20 individual J2 from each egg mass were exposed to endospores of a population of Pasteuria penetrans originally isolated from a population of Meloidogyne javanica and the endospores adhering to each J2 were counted. One population of M. incognita became encumbered with between nine to more than 100 endospores per J2 while in the other population this ranged from zero to less than 70 endospores per J2. The distribution of the numbers of endospores attaching to individual J2 was therefore very different and in one population of M. incognita the number of endospores were highly skewed with the majority of J2 having fewer than ten endopores and one or two J2 having more than 30. The experiment was repeated and similar results were obtained. The results will be discussed in relation to clonal variation and their implications. 458 The in uence of Tagetes patula on Pratylenchus penetrans and the growth of rose rootstocks Lutgart D E W AEL ¤ , Geraerard H ENDRICKX and Maurice M OENS Crop Protection Department, Agricultural Research Centre, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ l.wael@clo.fgov.be The in uence of growing Tagetes patula cv. Single Gold or Italian ryegrass, and of applications of aldicarb (0.9 g a.i./m 2 / , matalaxyl (0.075g a.i./m 2 / , or 12-months fallow was investigated on Pratylenchus penetrans in a sandy soil. Nematode numbers decreased signi cantly after Tagetes but increased after Italian ryegrass. The fungicide had no effect on the nematode while the effect of aldicarb was only temporary. Fallow resulted in a decrease of P. penetrans . To estimate the effect of the treatments, the stem diameter and plant weight of subsequently grown rose rootstocks Rosa dumetorum cv. Laxa were measured. Signi cant increase in both plant parameters was obtained after both Tagetes and aldicarb. The other treatments had no effect. 459 Field evaluation of the effect of Verticillium chlamydosporium on Meloidogyne arenaria race 3 Vol. 4(2), 2002 283</p>
<p>Biological control (449-488) M. Clara V. DOS S ANTOS , Isabel M. DE O. A BRANTES , So a DOS S. DA R. C OSTA and M. Susana N. DE A. S ANTOS Instituto do Ambiente e Vida, Departamento de Zoologia, Universidade de Coimbra, 3004-517 Coimbra, Portugal nemz@zoo.uc.pt The concern and restriction on nematicide use require the development of alternative nematode control strategies. The nematophagous fungus Verticillium chlamydospo- rium has shown potential as a biological control agent for root-knot nematodes in pot and microplot experiments. A 2-year eld experiment was conducted at Coimbra, Por- tugal, to study the effect of V. chlamydosporium on Me- loidogyne arenaria race 3. Tomato cv. Joker, susceptible to the nematode, and cabbage, as a poor host, were used in the summer and winter seasons, respectively. The ex- periment compared the use of V. chlamydosporium with the nematicides oxamyl and methyl bromide. Nematode population densities, gall index and number of eggs g ¡ 1 root were higher after the tomato crop. The fungus was able to colonise only the tomato roots and was detected in soil and in nematode eggs only after 2 years. Under the conditions of this experiment, the fungus was not effec- tive in decreasing nematode levels. A longer period would be needed for the fungus to be established and effective against root-knot nematodes. Further research, exploring environmental factors that also affect survival and prolif- eration of the fungus in soil, is needed to increase coloni- sation of soil and roots by the fungus. 460 A Pasteuria -like organism on an entomopathogenic nematode parasite of Diaprepes abbreviatus F.E. E L -B ORAI , L.W. D UNCAN and D. D UNN University of Florida, Citrus Research and Education Center, 700 Experiment Station Rd, Lake Alfred, FL 33850, USA During a eld study of endemic entomopathogenic ne- matodes in Florida, Pasteuria -like spores were frequently found adhering to 3rd stage juveniles (IJ3) of Steinernema sp. emerging from cadavers of the weevil Diaprepes ab- breviatus . Cadavers with emerged IJ3 were maintained in 2 ml water in sealed Petri dishes and observed peri- odically. Numbers of unattached spores in the water in- creased over time. Spores were never found attached to the IJ3 sheath (2nd stage cuticle), whereas most exsheathed IJ3 were encumbered with several hundred spores. A few ( < 1%) ensheathed IJ3 had one to several spores attached to the cuticle within the sheath. Twenty-six days after egression, numerous unattached spores were observed be- tween the 2nd and 3rd stage cuticles of some ensheathed nematodes; however, no spores were observed within the bodies of those IJ3. When spore-encumbered IJ3 were used to infect D. abbreviatus larvae, no spores were de- tected on juvenile or adult male or female nematodes up to 96 h after insect death. However, moulted cuticles of IJ3 with attached spores were recovered from dissected insect cadavers. Studies are ongoing to determine the life cycle of the organism relative to the nematode and insect. 461 Ef cacy of Pochonia chlamydosporia var. chlamydosporia and Paecilomyces lilacinus on biocontrol of Heterodera schachtii on sugar beet Seddigheh F ATEMY Nematology Department, Plant Pests and Diseases Research Institute, P.O. Box 1454-19395, Tehran, Iran Different isolates of Pochonia chlamydosporia var . chlamydosporia and Paecilomyces lilacinus were highly effective in controlling nematodes on water agar. A glasshouse experiment was conducted using P. lilacinus and four isolates of P. chlamydosporia var . chlamydosporia (Po1, Po3, Po4, Po5). Seedlings of sugar beet were planted in steam-sterilised soil and, at the same time, 100 g cereals infected with different fungi, and 5 g oxamyl were incorporated into the soil of appropriate treatments. After 27 days, plants were inoculated with 4000 juveniles of H. schachtii and pots were arranged randomly in a glasshouse for 2 months. There were signi cantly fewer cysts on the roots treated with fungi and oxamyl than untreated nematode-infected plants; the smallest numbers observed were on Po1 treated roots. Fresh weight of these plants signi cantly increased with addition of fungi and oxamyl. Nematodes multiplied nearly 22-fold on untreated plants, 11-fold on P. lilacinus and Po3 treatments and between two to ve-fold on plants treated with Po1, Po4 and Po5, respectively.Percent control of H. schachtii numbers (eggs/g soil) were 46% for Po3, 52% for P. lilacinus , 78% for Po4, 87% for Po1 and 90% for Po5, respectively. 462 Production of Pasteuria penetrans ‘ in vivo’ in soils with different textures and in the sand C.B. G OMES 1 ; ¤ , L.G. F REITAS 2 , S. F ERRAZ 2 , R.D.L O LIVEIRA 2 and W.B. S CIVITTARO 1 284 Nematology</p>
<p>Poster sessions 1 Embrapa Clima Temperado, C.P. 403, 96001-970, Pelotas-RS, Brazil 2 Universidade Federal de Viçosa, Depto Fitopatologia, 36571-000, Viçosa-MG, Brazil ¤ cbauer@cpact.embrapa.br The mass production and attachment of Pasteuria penetrans to Meloidogynejavanica second stage juveniles (J2) were evaluated in soils of different textures and in river sand, in the glasshouse. Tomato seedlings were transplanted to pots containing those substrates. The upper 5 cm layer of the substract was infested with 10 5 endospores/g soil of P. penetrans , and each plant was inoculated with 2000 J2. Seventy days later, the plant roots were harvested, dried, weighed and ground. The number of endospores/g of root, and per plant were estimated. Soil samples were collected from upper layer and from the bottom of each pot, dried, and infested with 600 J2 of M. javanica to evaluate the endospore percolation of P. penetrans . More endospores/plant were produced in sandy soils compared to clay soils or river sand. Negative correlation was observed between P. penetrans production per plant and the soil clay content. Soils with lighter texture allowed higher attachment of P. penetrans to juveniles of M. javanica than heavier ones. Most of the endospores were leached to the bottom of the pot by the percolating water in the sand. 463 Nematicidal activity of selected plant tissues to Xiphinema americanum John M. H ALBRENDT ¤ and James A. L AMONDIA Penn State University, 290 University Drive, Biglerville, PA 17307, USA; The Connecticut Ag. Expt Station, 153 Cook Hill Road, Windsor, CT 06095, USA ¤ jmh23@psu.edu Freeze-dried leaf and root tissue of six plants includ- ing edible mum ( Chrysanthemum coronarium ), black- eyed Susan ( Rubeckia hirta ), marigold ( Tagetes minuta ‘polynema’), sunn-hemp ( Crotalaria juncea ), castor bean ( Ricinus communis ) and sesame ( Sesamum indicum ) were assayed for nematicidal activity against the dagger ne- matode ( Xiphinema americanum ). The tissue was pul- verised and mixed with dry sterile sand in concentrations that ranged from 0.5-5.0 mg/cm 3 sand for roots and 5.0- 20.0 mg/cm 3 sand for leaves. Nematodes were transferred to 2 ml sample cups in 250 ¹ l sterile distilled water fol- lowed by 1.5 cm 3 of the plant/sand mix. The cups were sealed and incubated for 24 h at 24 ± C. All nematodes were recovered and the numbers of alive and dead nematodes were analysed by probit analysis. Chrysanthemum roots were the most toxic with an LC50 of 1.0 mg/cm 3 fol- lowed by black-eyed Susan with an LC50 of 3.5 mg/cm 3 . Sesame roots showed some activity but no mortality was observed in the marigold, castor bean or crotalaria root bioassays. Leaves of marigold and black-eyed Susan had LC50 values of 8.0 and 9.0 mg/cm 3 , respectively, while leaf tissue of the remaining plants showed little toxic ac- tivity. 464 Occurrence and biocontrol potential of potato-associated bacteria Johannes H ALLMANN 1 , Annekathrin F AUPEL 1 , Annette K RECHEL 2 and Gabriele B ERG 2 1 Institute of Plant Diseases, Bonn University, Nussallee 9, D-53115 Bonn, Germany 2 Institute for Molecular Physiology and Biotechnology, Rostock University, Albert-Einstein-Str. 3, D-18051 Rostock, Germany Plant-associated bacteria are able to improve plant growth and health, but little is known about their diversity and antagonistic potential against disease complexes consisting of plant parasitic nematodes and soil-borne fungi. In a cooperative project, bacteria were isolated from the rhizosphere, endorhiza, phyllosphere and endosphere of potato cv. Cilena at Bonn and Rostock, and studied for their antagonistic potential against Verticillium dahliae / Rhizoctonia solani (Rostock) and Meloidogyne incognita (Bonn). The bacteria were characterised based on their fatty acids using standard procedures for GC- FAME and the Sherlock Microbial Identi cation System (MIDI). Bacterial richness and diversity were determined to compare population dynamics depending on location, habitat and growth stage. Up to 10% of the culturable bacteria showed antibiosis against V. dahliae and R. solani . Out of these isolates, 20% gave signi cant control of M. incognita in greenhouse experiments. Main bacterial genera containing isolates with antagonistic activity were Curtobacterium and Streptomyces for the rhizosphere and phyllosphere and Pseudomonas for the endosphere and endorhiza. In 2001, samples were taken at three different growth stages (establishment, owering, maturity). Differences in bacterial community structure and antagonistic activity will be shown. The potential of indigenous antagonistic bacteria to suppress nematode/fungal diseases complexes is discussed. Vol. 4(2), 2002 285</p>
<p>Biological control (449-488) 465 Study of combined use of antagonist plants and arbuscular mycorrhizal fungi on Meloidogyne incognita on tomato M.C. J AIZME -V EGA ¤ , A.S. R ODRÍGUEZ -R OMERO , P. G ARCÍA D E L A R OSA , P. A FONSO M ORALES and L.A. B ARROSO N ÚÑEZ Instituto Canario de Investigaciones Agrarias (ICIA), Dpto Protección Vegetal, Apdo 60 38200 La Laguna, Tenerife, Spain ¤ mcjaizme@icia.es Organic disease management programmes are being in- creasingly researched in order to limit the environmental pollution caused by standard agricultural methods. Cur- rently, much research is focusing on nematode control using antagonist plants with nematicidal properties such as aromatic species which produce essential oils with ac- knowledged nematicidal and fungicidal properties, and the Tagetes spp. with a known suppressive effect on par- asitic nematodes. Glasshouse trials were set up to eval- uate the combined effects of inoculation with the mycor- rhizal fungi Glomus mosseae or Glomus manihotis and the presence of either the aromatic herb Lavandula dentata or Tagetes minuta on tomato infected with the root-knot ne- matode Meloidogyne incognita . The results show signif- icant differences in nematode reproduction between my- corrhizal and non-mycorrhizal plants with an important reduction in nematode levels in the plants inoculated with arbuscular mycorrhizal fungi and cultured in the presence of antagonist plants. 466 Occurrence of Rhizobium radiobacter associated with Heterodera avenae eggs in Tunisia Najoua K ACHOURI -N AMOUCHI 1 ; ¤ and Mouldi M. B’C HIR 2 1 INRAT, 2049 Ariana, Tunisia 2 INAT 1082 Cité mahrajène, Tunis, Tunisia ¤ kachouri.najoua@iresa.agrinet.tn Populations of cereal cyst nematode, Heterodera avenae , collected from various cereal regions in Tunisia were associated with several bacterial and fungal strains. Scanning electron microscopy study has demonstrated the occurrence of a bacterium within the cyst and eggs of the populationnematode collected from Zaghouan region. This bacterium has been puri ed through micro-culture of disinfected eggs on agar media. The bacteria was then identi ed using ampli cation of ‘rrs’ gene coding the ARNr 16S as Rhizobium radiobacter synonymous with Agrobacteriumradiobacter . The role and importance of the bacteria-nematode relationship on the host are discussed. 467 Isolates of the generalist parasite Pochonia chlamydosporia have speci c interactions with their nematode hosts B.R. K ERRY ¤ , C.O. M ORTON , T.H. M AUCHLINE and P.R. H IRSCH Nematode Interactions Unit, IACR-Rothamsted, Harpenden, Hert, AL5 2JQ, UK ¤ brian.kerry@bbsrc.ac.uk Pochonia chlamydosporia is an opportunistic, facultative parasite of cyst and root-knot nematode eggs, fungi and molluscs, but individual isolates demonstrate host speci c interactions. Genetic variation was examined in a collection of 54 isolates from diverse geographical regions and several nematode hosts using ERIC PCR. In cluster analysis, isolates formed groups on the basis of their original host; those from cyst nematodes varied more than those from Meloidogyne spp. The fungus produces an alkaline serine protease, VCP1, during infection of nematode eggs. The gene encoding VCP1 was sequenced and cDNAs from six isolates from different nematode hosts examined. Translated cDNA sequences in isolates from cyst and root-knot nematodes consistently had two amino acid polymorphisms at positions 65 and 99 in the binding region of the enzyme. Such differences may contribute to host preference. Isolates from cyst or root-knot nematodes were added alone and together to soil in which tomato or potato plants infected with Globodera pallida or Meloidogyne incognita were grown. Isolate abundance was increased only in compatible combinations and the species of nematode in uenced the proportions of the mixed isolates. Pochonia chlamydosporia has complex interactions with its hosts that may in uence its biological control ef cacy. 468 Comparative study on the nematicidal activities of garlic and mustard oils P.S. K ING and R. R ODRÍGUEZ -K ÁBANA Dept of Entomology and Plant Pathology, Auburn University, Alabama 36849, USA The nematicidal properties of mustard and garlic oils were compared to those of allyl isothiocyanate in a 286 Nematology</p>
<p>Poster sessions glasshouse study. Five percent (v/v) acetone solutions of allyl isothiocyanate, garlic oil and mustard oil were prepared and each delivered at rates of 0.1, 0.2, 0.4 and 0.8 ml a.i./kg soil that was naturally infested with Rotylenchulus reniformis . Treated soils and untreated control were placed in pots in the glasshouse. Pre-plant soil samples for nematode analysis were collected 1 week after application of the materials. The pots were planted with soybean ‘Young’ and grown for 8 weeks. Plants were then removed and nematodes were extracted from soil and roots. Fresh shoot weights were determined. Pre-plant sampling results indicated that all three materials were active against the nematode when applied at rates > 0.2 ml/kg soil. Nematicidal activities of allyl isothiocyanate and mustard oil were much higher than that of garlic oil. In the end-of-experiment sampling, populations of reniform nematodes in soil were lowest in soils treated with the two highest rates of allyl isothiocyanate and the 0.8 ml rate of mustard oil; numbers in soil with garlic oil did not differ from the control. Nematode populations in the roots followed the same pattern as for the soil samples, except that the 0.8 ml rate of garlic oil reduced nematode numbers compared to the control. Treatments with allyl isothiocyanate and garlic oil had no effect on shoot weight; those with mustard oil at > 0.1 ml/kg soil resulted in improved shoot weights. Results indicate that garlic oil does not have the nematicidal properties shown by allyl isothiocyanateand mustard oil. 469 Mechanism of action of Corynebacterium paurometabolum strain C-924 on nematodes Jesús M ENA 1 ; ¤ , Eulogio P IMENTEL 1 , Armando T. H ERNÁNDEZ 1 , Liuven V ELOZ 1 , Ramón P. V ÁZQUEZ 2 , Licette L EÓN 1 , Juan D. M ENCHO 3 , Yamilka R AMÍREZ 1 , Merardo P UJOL 1 and Carlos B ORROTO 1 1 Centro de Ingeniería Genética y Biotecnología, P.O. Box 387, Camagüey 70100, Cuba 2 Laboratorio Provincial de Sanidad Vegetal de Camagüey, Cuba 3 Universidad de Camagüey, Cuba ¤ jesus.mena@cigbcam.cigb.edu.cu Simultaneous production of hydrogen sulphur and chitinases by Corynebacterium paurometabolum strain C- 924 was demonstrated. It happens in suf cient amounts to impede egg hatching and produce death in juveniles of several species of plant and animal parasitic nematodes. This result permitted further study of the mechanism of action against other parasites (trematodes, fungi and bacteria). It was also demonstrated in several experiments that concurrent applications of chitinolytic agent or a chitinolytic activity-inducing agent, and sulphide or sulphide-producing agents from microorganisms or chemical compounds, required ranges or doses of application signi cantly less than any of the compounds applied individually, in order to achieve an effective control of the nematodes. This indicates that there is a synergistic effect in the combination of chitinases and sulphide for the control of nematodes and other parasites. The results are subject of a patent application on any antiparasitic composition obtained from the metabolites of Corynebacterium paurometabolum strain C-924, as well as some other possible antiparasitic compositions and biocontrol microorganisms producing chitinases and sulphide concurrently. 470 Population of Corynebacterium paurometabolum strain C-924 in soils treated with HeberNem Jesús M ENA 1 ; ¤ , Liuven V ELOZ 1 , Ramón P. V ÁZQUEZ 2 , Manuel E XPÓSITO 1 , Marieta M ARÍN 1 , Eladio S ALAZAR 1 , Licette L EÓN 1 , Yaisa C OCA 1 , Yamilka R AMÍREZ 1 , Gustavo R ODRÍGUEZ 1 , Armando T. H ERNÁNDEZ 1 and Eulogio P IMENTEL 1 1 Centro de Ingeniería Genética y Biotecnología, P.O. Box 387, Camagüey 70100, Cuba 2 Laboratorio Provincial de Sanidad Vegetal de Camagüey, Cuba ¤ jesus.mena@cigbcam.cigb.edu.cu A procedure to re-isolate bacterium Corynebacterium paurometabolum strain C-924 from ferritic soils treated with HeberNem, was developed.Strain C-924 is the active agent of HeberNem, a new bionematicide formulated as a concentrated and humectant powder. It was tested in glasshouses on several crops, such as pepper and tomato. HeberNem applications were carried out by means of the irrigation system in doses from 1 to 5 kg/ha. A selective culture medium was developed, taking into account antibiotic combinations and also based on bacteria colony chromogenesis for potassium telurite reduction, so the differentiated re-isolation from soil samples of the speci c strain C-924 was performed. The results con rmed the effectiveness of the bacterium in the control of Meloidogyne incognita , when it is in a concentration higher than 10 5 ufc/g of soil. It was proven that soil populations of C-924 diminished progressively Vol. 4(2), 2002 287</p>
<p>Biological control (449-488) and it was not possible to detect it in treated ferritic soils between 60 and 120 days. It was concluded that for the best effectiveness of the product, a rst application should be done 7 days before planting and a second one 30 days after it, using doses between 2 and 5 kg/ha. 471 Examination of rhizosphere-associated microbes for production of compounds active against plant-parasitic nematodes Susan L.F. M EYER 1 ; ¤ , Daniel P. R OBERTS 2 , James K. N ITAO 1 and David J. C HITWOOD 1 1 USDA, ARS, Nematology Laboratory, Bldg 011A, Rm 165B, BARC-West, 10300 Baltimore Avenue, Beltsville, MD 20705-2350, USA 2 USDA, ARS, Sustainable Agriculture Systems Laboratory, Bldg 001, Rm 140, BARC-West, 10300 Baltimore Avenue, Beltsville, MD 20705-2350, USA ¤ meyerf@ba.ars.usda.gov In vitro studies identi ed fungi and bacteria that produce compounds active against plant-parasitic nematodes. Assays of fungus culture ltrates were conducted with Heterodera glycines (soybean cyst nematode: SCN) and Meloidogyne incognita (root-knot nematode: RKN). The tested ltrates exhibited a low correlation in activity against SCN compared with activity against RKN. Only 5.1% of the tested isolates produced culture ltrates that strongly inhibited egg hatch of both SCN and RKN ( i.e ., egg hatch was 40% or less than egg hatch in potato dextrose broth controls), 3.9% strongly inhibited SCN egg hatch only, and 13.4% inhibited RKN egg hatch (but not SCN). Percentages of ltrates that inhibited second stage juvenile mobility were 0.8% (affected both SCN and RKN), 0.4% (SCN only), and 1.2% (RKN only). Compounds with broad-spectrum activity can be identi ed without testing speci c nematode taxa, but identi cation of compounds with more speci c activity should be tested against the target nematode. Similar experiments with rhizosphere-inhabiting bacteria and RKN identi ed isolates producing compounds active against RKN. One ltrate that suppressed egg hatch was selected for further study; size-fractionation of the culture ltrate showed that the active componentis larger than > 3 kDa in size. 472 Morphological and morphometric characteristics of Sri Lankan populations of mature endospores Pasteuria K.M. M OHOTTI 1 ; ¤ , S.R. G OWEN 2 and J. B RIDGE 3 1 Tea Research Institute of Sri Lanka, Talawakele, 22100, Sri Lanka 2 University of Reading, UK 3 CABI Bioscience (UK Centre), UK ¤ mohottik@yahoo.com The morphology and morphometrics of mature en- dospores of Pasteuria populations recovered from Sri Lankan nematodes belongingto several taxonomic groups were evaluated. Pasteuria populations originating from Meloidogyne and Pratylenchus from Australia, Japan, Kenya and UK were also included in the study for com- parison. A wide variation in spore morphometrics was evident. Meloidogyne yielded comparatively large spores while Pratylenchus and Radopholus generated small spores; intermediate sizes were seen with Xiphinema . Sri Lankan endospores possessed morphologicalchanges fol- lowing attachment onto nematodes. The endospores that originated from Sri Lankan soils had the three distinct forms (I-III). PPKB exhibited the very rare Form I; PPKB attached to M. brevicauda retained the sporangium wall covering the surface. PPPT exhibited rough intact pe- ripheral bres and the central body of the endospores was attached to Pratylenchus loosi after the sporangium wall and the exosporium were sloughing off. PPNW en- dospores possessed peripheral bres as ne, delicate, re- markably long and prominent hairy structures. Spores of PPKenya isolated from P. goodeyi and PPBotesdale iso- lated from M. ardenensis were found to be smallest and largest, respectively, described so far among the mem- bers of the Pasteuria penetrans group. PP-a also showed a higher mean endospore diameter. 473 Endophytic behaviour of egg parasitic fungi in roots E. M ONFORT , J.J. B ORDALLO , J. S ALINAS , L. A SENSIO and L.V. L OPEZ -L LORCA Departamento de Ciencias Ambientales y Recursos Naturales, Universidad de Alicante, Aptdo correos 99, 03080, Alicante, Spain The rhizosphere is an important zone for the activity of nematophagous fungi since plant-parasitic nematodes commonly attack plant roots. Micro-organisms are found in numbers ten to 20 times (occasionally 100 times) higher than in the root-free soil. The presence of nematode- trapping fungi in the rhizosphere of agricultural plants has been studied. The capability to colonise the roots was 288 Nematology</p>
<p>Poster sessions not advantageous for the biocontrol potential of isolates on root-knot nematode ( Meloidogyne spp.), in contrast to the egg-parasitic fungus Verticillium chlamydosporium , where root colonisation was suggested to be a prerequisite for successful biological control. We have recently shown cellular details of barley root colonisation by V. chlamydosporium . It seems that the fungus is not recognised by the plant, similar to mycorrhizae and non-pathogenic endophytes. We have also found signs of late induction of plant defence responses (3 weeks after inoculation) such as phenolic droplets and papillae similar to how other fungal antagonists of plant pathogens modulate plant defences. We therefore hypothesise a double mode of action for V. chlamydosporium and perhaps other nematophagous fungi: i ) direct parasitism on nematode eggs; and ii ) immunisation agent. We present our initial results on plant defence modulation by V. chlamydosporium and show examples of its potential to control root pathogens. 474 The potential of TerraPy ® to reduce nematode damage M ULAWARMAN 1 , Johannes H ALLMANN 2 , Doris B ELL 3 and Richard A. S IKORA 1 1 Institute of Plant Diseases, Bonn University, Nussallee 9, D-53115 Bonn, Germany 2 Federal Biological Research Center, Toppheideweg 88, D-48161 Münster, Germany 3 Cognis Deutschland, Henkelstrasse 67, D-40551 Düsseldorf, Germany TerraPy stimulates microorganism activity in the soil and promotes growth of plant-bene cial microorganisms such as mycorrhiza and plant growth promoting rhizobacteria (PGPR). As a result, damage caused by plant parasitic ne- matodes is reduced. In greenhouse experiments, Meloido- gyne incognita infestation on tomato was signi cantly re- duced following a soil drench with TerraPy at 2 kg/ha. In- creasing application rates up to 200 kg/ha further reduced nematode damage. At these higher rates, plant growth was also signi cantly enhanced. Yield of cherry tomatoes was 50% higher when treated with 200 kg/ha TerraPy than in the control. The increase in yield was caused by more fruits per plant. However, fruit weight was not affected. Similarly, for commercial tomato production in Turkey an increase in the number of owers is reported as major factor of yield enhancement. Due to its positive effect on bene cial microorganisms, coapplication of TerraPy with mycorrhiza or Pseudomonas inoculum will further reduce nematode damage and stimulate plant growth. In 2001, TerraPy was successfully marketed in the mediterranean region as a plant growth and yield-enhancingagent in veg- etables. 475 Ultrastructural study by TEM of eggs and juveniles of nematodes treated with Corynebacterium paurometabolum strain C-924 Eulogio P IMENTEL 1 ; ¤ , Jesús M ENA 1 , Abel H ERNÄNDEZ 1 , Ramón P. V ÁZQUEZ 2 , Marina F ERNÁNDEZ 2 , María C. D E L A R OSA 1 , Ivon M ENÉNDEZ 1 , Liuven V ELOZ 1 , Licette L EÓN 1 and Viviana F ALCÓN 1 1 Centro de Ingeniería Genética y Biotecnología, P.O. Box 387, Camagüey 70100, Cuba 2 Laboratorio Provincial de Sanidad Vegetal de Camagüey, Cuba ¤ eulogio.pimentel@cigbcam.cigb.edu.cu Changes in the ultrastructure of Haemonchus spp. eggs, treated with Corynebacterium paurometabolum strain C- 924, were observed by Transmission Electron Microscopy (TEM). Alterations in the eggs of Haemonchus spp. exposed to the action of the bacterium, were detected after 12 h treatment. Regions normally containing lipids were occupied by determined vacuolar spaces, which separated the lipidic and chitinous layers. Closely bound to these spaces, numerous foldings produced in the external layer of the eggs were observed as the main damage suffered in eggshell. These structures were not observed in the eggs without C-924 treatment. It was also observed that C. paurometabolum strain C-924, caused the death of Meloidogyne incognita second stage juveniles (J2). After 24 h exposure to C-924, vacuoles observed for Haemonchus spp. eggs were smaller than for the M. incognita J2. This situation could be related to greater susceptibility of M. incognita J2 to gases emitted by the bacterium. Studies on toxic gas production, proteolytic activity, as well as the capacity of C. paurometabolum strain C-924 to degrade chitin and collagen are proposed. 476 The relationship between glucosinolates in canola ( Brassica napus ) and their ability to control the plant-parasitic nematodes, Pratylenchus neglectus and Meloidogyne javanica Mark P OTTER 1 ; ¤ , Ekaterina R IGA 2 , Graham S TIRLING 3 and Sharyn T AYLOR 4 Vol. 4(2), 2002 289</p>
<p>Biological control (449-488) 1 Adelaide University, Department of Applied and Molecular Ecology, PMB 1 Glen Osmond, SA 5064, Australia 2 Washington State University, P.O. Box 646430 Washington State University, Pullman, Washington 99164, USA 3 Biological Crop Protection Pty Ltd, 3601 Moggill Rd Moggill, Queensland 4070, Australia 4 South Australian Research and Development Institute, GPO Box 397, Adelaide, 5001, Australia ¤ potter.mark@saugov.sa.gov.au The toxicity and susceptibility of canola ( Brassica napus ) plants containing different root levels of glucosinolates were tested against the root lesion ( Pratylenchus neglec- tus ) and root-knot ( Meloidogyne javanica ) nematodes in glasshouse trials. Plants containing higher root levels of 2-phenylethyl glucosinolate were signi cantly more re- sistant to P. neglectus and more toxic as they degraded in the soil. This con rms previous ndings, and suggests that high root 2-PE glucosinolatecanola crops should pro- vide a disease break effect against this nematode. High 2-PE glucosinolate tissues were also more toxic to popu- lations of M. javanica , but plants showed no signi cant advantage in terms of resistance to the nematode. In fact, a signi cant and positive relationship between glucosino- late levels and nematode numbers generated was observed in one variety, suggesting that the elevated presence of the glucosinolate actually gave the nematode an advantage. The disease break effect of the crop against the root-knot nematode may be undermined by its susceptibility,and so caution should be used in crop selection in areas where the root-knot nematode is a problem. 477 Examination and disclosure of the multifaceted modes of action of DiTera ® , a biological nematicide Linda R EHBERGER ¤ , Bassam S HAMMO and Prem W ARRIOR Valent BioSciences Corporation, 6131 RFD Oakwood Road, Long Grove, IL 60047, USA ¤ linda.rehberger@valent.com Research laboratories such as IACR-Rothamsted, Impe- rial College, UK and Auburn University, AL, were in- volved in the investigation into the complex activities found in DiTera ® (a biological nematicide) on plant- parasitic nematodes, during 1997-2000. Egg hatch inhi- bition, muscle paralysis, feeding inhibition, depletion of lipids, and changes in sensory perception affecting activ- ities such as host/mate- nding were affected by exposure to DiTera ® . In most instances these activities were found to be irreversible. In addition to nematode activities, in- creased plant health, shoot and root weights and greening were also noted in multiple eld trials, prompting inves- tigations into microbial changes in DiTera ® treated soils in greenhouse and under eld conditions. Various stud- ies including FDA hydrolysis, enzymatic activity, pH and conductivity measurements, and determination of soil, root tissue and rhizosphere microbial populationsdemon- strated DiTera ® increased gram-positive microbial popu- lations especially in the rhizosphere and soil. These direct and indirect effects on nematodes and the soil rhizosphere contributes to the overall bene cial response of plants to DiTera ® . 478 Effect of mycorrhizal arbuscular fungus Glomus manihotis on micropropagated banana cultured on soil naturally infested by lesion nematode under microplot conditions A.S. R ODRÍGUEZ -R OMERO ¤ , M.C. J AIZME -V EGA and L.A. B ARROSO N ÚÑEZ Instituto Canario de Investigaciones Agrarias (ICIA), Dpto Protección Vegetal, Apdo 60, 38200 La Laguna, Tenerife, Spain ¤ arguezr@icia.rcanaria.es The root lesion nematode Pratylenchus goodeyi Sher & Allen is considered an important nematode pest of commercial bananas in the Canary Islands. Arbuscular mycorrhizal fungi (AMF) are obligate symbionts that colonise the roots of most cultivated plant species. It has been demonstrated that early mycorrhizal inoculation promotes plant growth and increases the tolerance of banana to attack by nematodes. However, most interaction studies between both microorganisms have been developed during the nursery phase where most conditions are under control. In this trial we study the effect of the interaction between the AMF Glomus manihotis and Pratylenchus goodeyi on micropropagated banana Grande Naine, under microplot conditions. This experimental method is the nearest to eld conditions. Several samples were taken at different times to evaluate mycorrhizal effect and nematode infection. Six months after transplanting to microplots there was still a positive effect of AMF. This effect decreased at the end of trial, after 18 months in the microplots. At nal harvest, plants showed important levels of nematode infection and the consequent damage. 290 Nematology</p>
<p>Poster sessions 479 The elaboration of biological control methods of nematode-, virus-, fungi-, bacteria-complex infections on leguminous plants N.D. R OMANENKO 1 ; ¤ , B.F. T ARAVALLI 2 and V.G. Z AEC 2 1 Institute of Parasitology of Russian Academy of Sciences, Moscow 117071, Leninskii prosp. 33, Russia 2 Russian University of Friendship of Peoples, Moscow, Russia ¤ nd_romanenko@mail.ru Nematodes, virus, fungi and bacteria and their associ- ations were studied in different type phytocenoses of Moscow on leguminous plants. The complex seed infec- tions included two to ve species, mainly of fungi and bacteria. The root and abovegroundplant organ-infections included,as a rule, ve more pathogens,consisting mainly of nematodes, fungi, bacteria and viruses. The meth- ods, dates and ef ciency of Russian biological pesticides (planrhiz, trichodermin) and nematicidal strains of bac- teria antagonists ( Bacillus , Pseudomonas ) and bacteria which secrete antibiotic substances ( B. polymixa, Enter- obacter spp.) were studied as ecologically safe methods to restrict the quantity and harmful in uence of complex infections (nematodes, viruses, fungi, bacteria) on legu- minous plants grown under the conditions of the Moscow region. The in uence of different species of plant prede- cessors on number and species of nematodes of different ecological and trophical groups in the process of growing leguminous plants in seven- eld crop-rotation were stud- ied. 480 Biocontrol of plant-parasitic nematodes by Tricoderma harzianum – possible role of proteases Edna S HARON 1 ; ¤ , Alfredo H ERERA -E STRELLA 2 , Ilan C HET 3 and Yitzhak S PIEGEL 1 1 Department of Nematology, Agricultural Research Organization (ARO), The Volcani Center, P.O.B. 6, Bet-Dagan 50250, Israel 2 Centro de Investigación y Estudios Avanzados, Plant Biotechnology and Genetic Engineering Unit, Apartado, Mexico 3 Otto Warburg Center for Agricultural Biotechnology, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Israel ¤ vpshedna@volcani.agri.gov.il Strains of the fungal biocontrol agent Tricoderma harzianum can affect the root-knot nematode Meloido- gyne javanica by various modes: i ) direct parasitism on second-stage juveniles (J2) and eggs; ii ) metabolites pro- duced by the fungus affect the J2 viability and egg hatch- ing. In vitro parasitism ability was presented, to different extents, by all the strains tested: IMI206040 (designated WT) and its transgenic strain P-2 which contains multi- ple copies of the proteinase gene prb1 , strains T-203(Y), T-44, T-35 and T-315. A transgenic strain of IMI206040 carrying a fusion of the prb1 promoter with the green uorescent protein (GFP) gene was used to demonstrate that this gene is turned on during the interaction between the fungus and the nematode. Culture ltrates of WT and P-2 paralysed and killed the M. javanica J2, as well as other plant-parasitic nematodes. The activity on M. java- nica J2 was heat sensitive and restricted to the low mole- cular weight fraction (less than 3 kDa). The higher mole- cular weight fraction, which contained the proteases, did not directly affect the J2. However, a ladder of proteases between 20-31 KDa, which presented optimal proteolytic activity at low pH range, was positively correlated to the nematicide activity of the various strains ltrates. 481 Evaluation of Polish isolates of nematophagous fungi for the control of the root-knot nematode ( Meloidogyne arenaria (Neal) Chitwood) in vitro and in glasshouse conditions Danuta S OSNOWSKA Institute of Plant Protection, Department of Biocontrol & Quarantine, ul. Miczurina 20, 60-318 Poznan, Poland D.Sosnowska@ior.poznan.pl The effects of different species of nematophagous fungi: Ponchonia chlamydosporia var. chlamydosporia , Paecilomyces lilacinus and Cylindrocarpon destructans on Meloidogyne arenaria eggs and juveniles were tested in vitro . All species of fungi were isolated from eggs of sugar beet nematode ( Heterodera schachtii ) and controlled M. arenaria population in vitro . Isolates Vc- 1 of P. chlamydosporia and P. lilacinus parasitised 90% of eggs, while C. destructans parasitised only 50%. C. destructans infected more than 19% of juveniles at a temperature of 25 o C, while P. chlamydosporia infected 3- 10% and none was infected by P. lilacinus . The potential of C. destructans as a biological control agent against M. arenaria in glasshouse conditions is under investigation and results will be presented. Vol. 4(2), 2002 291</p>
<p>Biological control (449-488) 482 Endotoxin activity of lipopolysaccharide produced by Moraxella osloensis , a bacterium associated with the nematode Phasmarhabditis hermaphrodita , against the slug Deroceras reticulatum Li T AN ¤ and Parwinder S. G REWAL Department of Entomology, The Ohio State University, Wooster, Ohio 44691, USA ¤ tan.100@osu.edu Moraxella osloensis is a gram-negative bacterium as- sociated with Phasmarhabditis hermaphrodita , a slug- parasitic nematode that has prospects for the biological control of mollusc pests, especially the grey garden slug Deroceras reticulatum . This bacteria-feeding nematode acts as a vector to transport M. osloensis into the shell cav- ity of the slug where the bacteria multiply and kill the slug within 1 to 2 weeks. We discovered that M. osloensis pro- duces endotoxin(s) highly toxic to the slug when injected into the shell cavity. Injection of puri ed lipopolysaccha- ride (LPS) from M. osloensis cultures into the shell cavity caused slug death with an estimated LD 50 of 48 ¹ g per slug. No contact or oral toxicity of the LPS to the slug was detected. Isolated lipid A portion from the LPS was toxic to the slug after injection into the shell cavity, but the polysaccharide portion of the LPS was not. Further, we semi-quantitated the LPS as 6 £ 10 7 endotoxin units per mg and detected endotoxin activity in the lipid A portion but not in the polysaccharide portion by limulus amoebo- cyte lysate assays. This appears to be the rst report of an active biological toxin against molluscs. 483 Research on the in uence of ve plant steroid substances on plant-nematode relationships (tomato – Meloidogyne incognita ) Z.V. U DALOVA 1 ; ¤ , S.V. Z INOVIEVA 1 , I.S. V ASILIEVA 2 and V.A. P ASESHNICHENCO 2 1 Institute of Parasitology, Russian Academy of Sciences, Leninskii pr., 33, Moscow, 119071, Russia 2 Bakh Institute of Biochemistry, RAS, Leninskii pr., 33, Moscow, 119071, Russia ¤ zudalova@mail.ru It is known that plant steroids, with various chemical structures, can in uence the growth and moult of parasitic nematodes and their hatch from eggs. The estimation of ve plant steroid substances (solasonine, eñdisone, solamargine, tomatosid and furostanol glycosides) on nematode and plant in the host-parasitic system (tomato – root-knot nematode Meloidogyne incognita ) was carried out. The data have shown that the treatment of seeds of tomatoes with water solutions (0.5 mg/ml) of the substances stimulated development of plants and suppressed nematodes. The size of galls and females of nematodes in tested plants were much less than in control plants. The treatment by eñdisone stimulated formation of males in a population. The most effective were the furostanol glycosides, solamargine and tomatosid. These reduced infestation of roots by nematodes and increased duration of development of the parasites 1.5-2 times. The combinations in the concentration used did not affect nematodes in vitro . It is possible that the action of some steroids (in particular eñdisone) is caused by their participation in biosynthesis and metabolism of moult and sexual hormones of nematodes, as it resulted in change of their age quali cation-sexual structure. 484 Effect of cultural practices on the management of Meloidogyne spp. on glasshouse crops by the nematophagous fungus Verticillium chlamydosporium Veerle V AN D AMME ¤ , Annemie H OEDEKIE , Wouter V ANHOVE and Nicole V IAENE Agricultural Research Centre, Crop Protection Department, Burg. Van Gansberghelaan 96, 9820 Merelbeke, Belgium ¤ v.vandamme@clo.fgov.be Several isolates of Verticillium chlamydosporium , an egg- parasitising fungus of Meloidogyne spp., were selected for application in commercial vegetable production in glasshouses. For this purpose, the fungus must be compatible with cultural practices such as fertiliser use, soil type and pesticide application. Glasshouse experiments in pots were performed to study the effects of those practices on the ef cacy of the biocontrol agent. Second-stage juveniles (J2) of Meloidogyne spp. were used as inoculum and tomato was the host plant. Fertilisers did not have negative effects on the ef cacy of V. chlamydosporium . Addition of the fungus together with inorganic, organic-mineraland pure organic fertiliser caused up to 75, 76 and 86% reduction in the number of J2 per 100 cm 3 soil, respectively. Without fertiliser, the effect of V. chlamydosporium on the nematode population was not signi cant. Of the four soil types tested, organic heat-sterilised soil had a negative in uence on the performance of V. chlamydosporium . In contrast, addition of V. chlamydosporium to organic untreated soil, mineral untreated soil and mineral heat-sterilised soil reduced between 71 and 82% of the numbers of J2 292 Nematology</p>
<p>Poster sessions per 100 cm 3 soil. The in uence of pesticide use on the performance of V. chlamydosporium will be discussed. 485 Compatibility of Corynebacterium paurometabolum strain C-924 with Nemacur and other chemical pesticides Ramón P. V ÁZQUEZ 1 ; ¤ , Jesús M ENA 1 , Liuven V ELOZ 1 , Yamilka R AMÍREZ 1 , Gilda J IMÉNEZ 2 , Victor M. P ICO 2 , Licette L EÓN 1 and Eulogio P IMENTEL 1 1 Centro de Ingeniería Genética y Biotecnología de Camagü, P.O. Box 387, CP 70100, Camagüey, Cuba 2 Laboratorio Provincial de Sanidad Vegetal de Camagüey, Cuba ¤ jesus.mena@cigbcam.cigb.edu.cu Interactions with chemical pesticides are required dur- ing the registration process of biological products. Bac- terium Corynebacterium paurometabolum strain C-924 is a representative case, which has been reported pre- viously as a new nematicidal agent (patent application PCT/NL95/00271). A selection of the eleven chemical pesticides, more widely used in agriculture, were tested in vitro . Pot experiments to con rm in vitro assays are shown, and positive results were obtained speci cally for Nemacur (phenamiphos). Interaction tests with chemical pesticides were developed under controlled conditions, growth inhibition zones of C-924 appear when interac- tions with different chemical products were performed. Three test concentrations of chemical pesticides were used for in vitro assays: work- eld, higher and lower con- centrations, so irregularities in eld conditionwhen chem- icals are used were taken into account. Different results were observed when using different chemical agents, so broad sensitivity range and resistance degrees are shown. Pot results and in vitro tests showed the possibility of us- ing both C. paurometabolum strain C-924 as a bionemati- cidal formulation and Nemacur in combination,for nema- tode control in Integrated Pest Management. 486 Evaluating the effect of TerraPy Ag ® on densities of Meloidogyne javanica and yield of tomato in a plastic house Soledad V ERDEJO -L UCAS ¤ and Magda G ALEANO IRTA, Ctra. de Cabrils s/n. 08348 Cabrils, Barcelona, Spain ¤ Soledad.Verdejo@irta.es TerraPy Ag ® stimulates microbial activity in the soil and promotes growth of bene cial plant organisms. The effect of TerraPy Ag ® on nematode densities, gall rating, and yield was evaluated in a plastic house. Tomato cv. Durinta was planted in March and harvested in July 2001. TerraPy Ag ® was applied at a total dose of 20 ml/m 2 per plot, split and applied in two ways: i ) monthly applications at a rate of 5 ml/m 2 for 4 months starting at planting, and ii ) application at a rate of 10 ml/m 2 in the 2nd and 3rd month after planting. Untreated plots served as control. Final densities, egg production,and gall rating were lower ( P < 0 : 05 / in plots treated monthly with 5 ml/m 2 of TerraPy Ag ® than in those left untreated. Densities in soil and root, and gall rating were unaffected by TerraPy Ag ® in the 2nd and 3rd month after planting. The number of fruits and their average fruit weight were higher ( P < 0 : 05 / in plots treated monthly with 5 ml/m 2 of TerraPy Ag ® than in those untreated. Percent yield increase in those plots was 30% with respect to untreated ones which provided a pro t of 18 030 euros/ha. 487 Observations on the life cycle of in vitro cultures of Pasteuria penetrans James H. W HITE 1 ; ¤ , John F. G ERBER 2 , Thomas E. H EWLETT 1 , Kelly S. S MITH 1 , Judith S. P HILLIPS 1 , Susan T. G RISWOLD 1 and Amanda K. M ORRIS 1 1 Entomos LLC, 445 SW 35 th Terr., Suite 310, Gainesville, FL 32608, USA 2 CDG Laboratories, Inc., Gainesville, FL, USA ¤ jim@entomos.com Studies of the life cycle of Pasteuria penetrans in Meloidogyne spp. have employed light microscopy, scanning electron microscopy and transmission electron microscopy. These studies used P. penetrans infected juveniles that were inoculated on plants, sequentially and temporally retrieved from roots and destructively sampled. The close association between P. penetrans cells and nematode tissue allows for observations of only large structures, i.e. , mycelial balls, thalli, and endospores. Development of in vitro culture techniques allows detailed observations of early, small growth structures of this bacterium. Early growth stages of this bacterium were recorded using light and scanning electron microscopy. These early growth stages progressed in in vitro cultures to classic P. penetrans structures, similar in size and shape to those reported from in vivo studies. Vol. 4(2), 2002 293</p>
<p>Biological control (449-488) 488 Sensitivity of Meloidogyne javanica and Tylenchulus semipenetrans to isothiocyanates in laboratory bioassays Inga Z ASADA ¤ and Howard F ERRIS Department of Nematology, University of California, Davis, CA 95616, USA ¤ iazasada@ucdavis.edu Isothiocyanates (ITC) are released upon enzymatic degra- dation of glucosinolates of Brassicaceae. Glucosinolate pro les differ among plant species and the associated ITC differ in toxicity to organisms. Control of plant-parasitic nematodes in soil by ITC from incorporated plant ma- terial has been unpredictable but might be improved by using species of Brassicaceae based upon chemical com- position. Laboratory assays were conducted to determine LC 50 values in sand of seven commercially-availableITC against second stage juveniles of Meloidogyne javanica and Tylenchulus semipenetrans . The relative toxicity of ITC (in ascending order) was: phenyl < ethyl < butyl < allyl < 4-(methylsul nyl)butyl < benzyl < phenylethyl for T. semipenetrans , and butyl < phenyl < ethyl < 4-(methylsul nyl)butyl < allyl < benzyl < phenylethyl for M. javanica . The LC 50 values ranged from 3.0 and 13.0 nmole/ml for phenylethyl ITC to 174.0 and 149.0 nmole/ml for phenyl ITC for T. semipenetrans and M. javanica , respectively. The broader context of this research is the development of approaches for consistent and reliable use of plant-derived chemicals for nematode management. The strategy is to select plants in the Brassicaceae based upon their glucosinolate pro les and the sensitivity of the target plant-parasitic nematode species to the associated ITC. 294 Nematology</p>
<p>Poster sessions 489 Effect of Oxycom on growth of tomato and reproduction of Meloidogyne incognita Safdar A. A NWAR ¤ and M.V. M C K ENRY ¤¤ University of California, Riverside CA 92521, USA ¤ anwar@uckac.edu ¤¤ mckenry@uckac.edu Single or multiple applications of Oxycom, peroxyacetic acid plus various biocontrol agents, were compared on 15- day-old susceptible tomato inoculated with 1500 second stage juveniles (J2) M. incognita. Forty pots were dipped into 2500 ppm (v/v) Oxycom, and 20 in water. Twenty of the 40 pots received four additional Oxycom applications at 10-day intervals. Plants were harvested at 60 days after inoculation to assess the effect of treatments on plant growth, nematode development and reproduction. A single treatment of Oxycom just prior to nematode inoculation signi cantly increased tomato top weight but not other growth parameters. Associated with plant growth bene t was a signi cant increase in the number of root-knot females. Multiple treatments of Oxycom signi cantly reduced leaf area, top weight and root weight while signi cantly increasing the number of galls, females and J2 per plant or per g of root. This study demonstrates that Oxycom stimulates plant growth and earlier fruiting while hastening nematode development. Proper timing and frequency of applications is important. No treatment reduced nematode population levels in this 60-day trial. 490 Dichloropropene with chloropicrin soil disinfection for nematode control in sweet pepper crops P. G UIRAO 1 , M.M. G UERRERO 2 , A. L ACASA 2 ; ¤ , C. R OS 1 , M. O NCINA 2 , M.C. M ARTÍNEZ 2 , M.A. M ARTÍNEZ 2 , C. B ELTRAN 2 and J. T ORRES 2 1 FECOAM-Consejería de Agricultura, Agua y Medio Ambiente, C/ Caballero 13, 30003 Murcia, Spain 2 Protección Vegetal, CIDA, Consejería de Agricultura, Agua y Medio Ambiente, c/Mayor s/n, 30.150 La Alberca, Spain ¤ Alfredo.Lacasa@carm.es In pepper glasshouses of the Southeast of Spain, Meloidogyne incognita and Phytophthora capsici are the main soil pathogens. Methyl bromide (MB 98:2) has been used for soil-borne pathogens in the last 17 years. The mixture 1,3-dichloropropene (60.5%) and chloropicrin (33.3%) (Telopic EC) applied with PE plastic at 50 g/m 2 by drip irrigation was assayed as an alternative to methyl bromide nematode control. In nine of the assays carried out since 1998 no signi cant differences were found Telopic EC and methyl bromide in M. incognita average root-knot index (Telopic: root-knot index D 0.5. MB: root-knot index D 0.5), marketable yield (Telopic: 9.4 kg/m 2 . MB D 9.3 kg/m 2 / or plant growth (Telopic D 137.3 cm. MB D 143.5 cm). However, the proportion of M. incognita infested plants (21.1%) on the mixture treatments was signi cantly higher than that of MB (5.1%). When application was repeated, marketable yield and plant growth at the 3rd year were similar but root-knot index was signi cantly higher on Telopic (21.1%) than on MB treatments (0.6). 491 Chemical options for the management of Heterodera schachtii in sugar beet under eld conditions Saad L. H AFEZ ¤ and Sundararaj P ALANISAMY University of Idaho, Parma Research and Extension Center, 29603 U of I Lane, Parma, Idaho 83660, USA ¤ shafez@uidaho.edu A eld experiment was conducted at the Parma Research and Extension Center, Parma, Idaho, to evaluate the ef cacy of Temik at different rates and timing on the sugar beet cyst nematode management in sugar beet. The experiment was laid out in a randomised block design with seven treatments each of ve replications. Temik was applied at planting on 31 May and Counter was applied at planting to individual plots (6 rows £ 50 ft). Sugar beet seeds were planted on 3 March in rows 22” apart. Application of Temik at planting of sugar beet or 3 months after planting signi cantly increased the beet yield as compared to the untreated control. In all treatments, application of Temik @ 33 lb/acre at planting increased the beet yield and beet vigour. Percent sugar yield was maximum at the rate of Temik 14 lb/acre at planting or the split application (at planting 20 lb/acre + post application 13 lb/acre). Temik performed better than Counter in terms of beet yield, percent sugar and beet vigour. 492 Evaluation of nematicides for the management of Meloidogyne chitwoodi on potato in Idaho Saad L. H AFEZ ¤ and Sundararaj P ALANISAMY University of Idaho, Parma Research and Extension Center, 29603 U of I Lane, Parma, Idaho 83660, USA ¤ shafez@uidaho.edu Vol. 4(2), 2002 295</p>
<p>Chemical control (489-499) A eld experiment was conducted at the Parma Research and Extension Center, Parma, Idaho, to study the ef cacy of Mocap and Temik in combination with Vapam and fosthiazate or Vydate for control of Columbia root-knot nematode in potato. Fosthiazate and Mocap treatments were surface broadcast on 4 May 2001 and Telone II and Vapam were applied on 27 March and 2 April, respectively. Potato cv. Russet Burbank seed pieces were planted on 18 April in rows 3 ft apart. Five months after planting, the tubers were hand-harvested from 15 ft of the middle two rows of each plot and weighed. Yield of tubers under different treatments indicated that there is an increase in market yield and total yield in different combinationsof Temik and Mocap as compared to control plot. Percent of nematode infected tubers in treated plots ranged from 3.9 to 13.4. Lowest level of nematode infection was observed in the treatment of 37.5 gal Vapam (3 tier shanks) + 2 gal Mocap. 493 Comparative ef cacy of Fosthiazate formulations for the management of Meloidogyne chitwoodi Saad L. H AFEZ ¤ and Sundararaj P ALANISAMY University of Idaho, Parma Research and Extension Center, 29603 U of I Lane, Parma, Idaho 83660, USA ¤ shafez@uidaho.edu Two eld experiments were conducted to study the ef cacy of Fosthiazate formulations along with Vapam on the control of Columbia root knot nematode ( Meloidogyne chitwoodi ) in a potato eld. Fosthiazate was applied at the rate of 8.6 or 11.5 pt/acre in the autumn of 1999 or spring of 2000 alone or along with Vapam (37.5 gal). Potato cv. Russet Burbank was planted on 21 March 2000. In the rst experiment, maximum marketable yield was recorded in the plots where Vapam was applied in autumn 1999 and fosthiazate in the spring 2000. In the second experiment, maximum marketable and total yield was observed in the plot treated with Vapam and Fosthiazate in spring 2000 before planting. Among all treatments, Fosthiazate with Vapam increased the marketable yield and total yield with the lowest nematode infection. Percent of nematode infection ranged from 0-1.9 and 0-17.4 in the rst and second experiments, respectively. 494 Ef cacy of dichloropropene with chloropicrin to control Meloidogyne incognita on pepper crops: rate of application and effect of plastic setting A. L ACASA 1 ; ¤ , M.M. G UERRERO 1 , C. R OS 2 , P. G UIRAO 3 , P. B IELZA 3 , J. T ORRES 1 , T. DE P ACO 3 , J. C ONTRERAS 3 , R. M OLINA 4 and M. T ORNÉ 4 1 Protección Vegetal, Centro de Investigación y Desarrollo Agroalimentario, CAAMA, c/Mayor s/n, 30.150 La Alberca (Murcia), Spain 2 FECOAM-Consejería de Agricultura, Agua y Medio Ambiente, C/Caballero, 13, 30003 Murcia, Spain 3 Producción Agraria, ETSIA, Universidad Politécnica de Cartagena. Paseo Alfonso XIII, s/n, 30.203 Cartagena-Murcia, Spain 4 Dow AgroSciences Iberica, S.A., c/Cerro de Castañar, 72B, 28034 Madrid, Spain ¤ Alfredo.Lacasa@carm,es The ef cacy of 1, 3 dichloropropene (60.5%) plus chloropicrin (33.3%) (Telopic EC) applied by drip irrigation has been evaluated in commercial pepper glasshouses in the southeast of Spain as an alternative to methyl bromide (BM 98:2 at 60 g/m 2 / Meloidogyne incognita control. The following treatments were assayed: 500, 400 and 300 l/ha with polyethylene plastic (PE); 300 and 200 l/ha with VIF plastic (Virtually Impermeable Film). Plastic set transversally and perpendicularly to the drip lines were assayed at 500 and 400 l/ha rates. All treatments were compared to MB 98:2 at 60 g/m 2 applied with PE and a non-treated control. The best results were obtained with 400 and 500 l/ha applied with PE. No signi cant differences were found in the percentage of infested plant, M. incognita root-knot average index, plant height and commercial yield. The use of VIF enhanced disinfection ef cacy and allowed rate reductions. No signi cant differences were found between transversal and longitudinal settings. Longitudinal plastic setting makes easier commercial Telopic EC application and reduces cost. 495 Effect of nematicides on Pratylenchus zeae Graham 1951 in sugar cane in Goias, Brazil V.O.F. M ACHADO 1 ; ¤ , P.M. F ERNANDES 1 , R.A.B. S OARES 2 , P.F.M. O LIVEIRA 2 and M.R. R OCHA 1 1 Escola de Agronomia/UFG, Campus Samambaia, Caixa Postal 131, CEP 74001-970, Goiânia-GO, Brazil 2 Jalles Machado S/A, Fazenda São Pedro s/n, Rodovia GO-080, km 71,5, Zona Rural, Caixa Postal 04, CEP 76380-000, Goianésia-GO, Brazil ¤ vmachado@agro.ufg.br 296 Nematology</p>
<p>Poster sessions Nematicides were applied in the elds pertaining to Jalles Machado S/A, municipality of Goianésia-GO, infested with Pratylenchus zeae Graham, 1951. The experiment was conducted during the period 03/1999 to 09/2000, utilising the randomised complete block design with four repetitions. The treatments utilised were as follows: i ) Check; ii ) Terbufos 50G 60 kg/ha; iii ) Terbufos 150G 20 kg/ha; iv ) Aldicarb 150G 10 kg/ha; v ) Carbofuran 50G 60 kg/ha; vi ) Thiamethoxam 250WG 20 kg/ha. The parameters of evaluation were the population density of nematodes (specimen/10 g of roots and specimen/100 g of soil) determined at 3, 6 and 9 months after planting and yield data of the variety RB72454, determined after 18 months. The nematicides showed ef ciency in reducing population level of plant nematode up to 6 months after their application and differed from the check and thiamethoxam treatment. The grain yield increase was signi cant as a result of plant nematode population reduction. The highest yield gains of 8.72 and 8.58 t/ha were obtained for Terbufos 150G and Carbofuran 50G treatments, respectively. 496 Evaluation of Messenger in combination with aldicarb or thiamethoxam for management of Rotylenchulus reniformis on cotton K.S. M C L EAN 1 ; ¤ and G.W. L AWRENCE 2 1 Department of Entomology and Plant Pathology, 209 Life Science, Auburn University, Auburn, AL 36849, USA 2 Department of Entomology and Plant Pathology, 103 Clay Lyle. Mississippi State University, Mississippi State, MS 39762, USA ¤ kmclean@acesag.auburn Messenger, a hairpin protein, was examined in Alabama and Mississippi for its effect on R. reniformis population development and cotton yields. Tests were established in locations which were in cotton production and had a history of reniform nematode infestation. Messenger was applied with a CO 2 charged backpack eld plot spray system as a broadcast spray using a 6 ft boom with 8002E at fan tip nozzles calibrated to deliver 95 l/ha. In Test 1, Messenger was applied at the two leaf stage (2LF), pin head square (PHS), full bloom (FB), and/or 3 weeks after full bloom (FB C 3) in combination with aldicarb (0.85 kg a.i./ha). In Test 2, Messenger was applied at 2LF, PHS, FB, and/or FB C 3 in combination with thiamethoxam (300 g a.i./100 kg seed) treated seed or aldicarb (0.59 or 1.2 kg a.i./ha) applied in-furrow at planting. In Test 1, in Mississippi, seed cotton yields were increased an average of 227 kg/ha in all Messenger and aldicarb combinations compared to aldicarb alone. However, in Alabama, Messenger did not increase cotton yields over aldicarb. In Test 2 in Mississippi and Alabama, the applications of Messenger C aldicarb (0.59 kg a.i./ha) averaged an increased seed cotton yield of 69.9 kg/ha over aldicarb (0.59 kg/ha) alone. Messenger did not increase cotton yields in either location when applied in combination with aldicarb at 1.2 kg a.i./ha. Messenger in combination with thiamethoxam treated seed increased yield in Alabama but not in Mississippi. 497 Abamectin effect on root-knot nematode population in melon hybrids W.A. M OREIRA ¤ and F.R. B ARBOSA Embrapa Semi-Arido, C.P. 23, CEP 56.300-970, Petrolina, PE, Brazil ¤ wmoreira@cpatsa.embrapa.br The ef ciency of abamectin on root-knot nematode populations was evaluated in three melon hybrids, Rochedo, Gold Mine and AF 646. The experiment was carried out in glasshouse conditions with two completely randomised factors and two independent treatments, with four replicates, each replicate comprising a plastic pot with two plants. Three levels of abamectin, equivalent to 27, 36 and 45 l of a.i./ha, were used. Naturally nematode infested soil, with initial populations determined as 30 second stage juveniles (J2)/cm 3 , was used. Variables root-knot index (0-4) and nematode reproductive factor ( Rf D Pf=P i/ , in the soil were evaluated. Root-knot index was signi cantly lower in chemical treatments, with highest reductions in population development of J2 being obtained with 45 l/ha. The highest nematode population incidence was observed in Gold Mine hybrid. 498 Controlling parasitic nematodes in an established vineyard in Cyprus John P HILIS Spyros Stavrinides Chemicals Ltd, P.O. Box 21278, Nicosia 1505, Cyprus johnphil@cytanet.com.cy Xiphinema index, Mesocriconema xenoplax and Paraty- lenchus hamatus are all pathogenic to grapevine ( Vitis vinifera L.). A trial in an established vineyard (cv. Sultan- ina) during 1999-2001has shown that the organophospho- rus contact nematicide cadusafos (as Rugby ® ) can effec- Vol. 4(2), 2002 297</p>
<p>Chemical control (489-499) tively control these nematodes whereas yields were also increased. It was applied as granules and in liquid for- mulation (microcapsules) in spring 1999 and 2000, at the rate of 3.5 g a.i. per sq. m. of actually treated area. Gran- ules were applied in 8 cm wide bands, near and at both sides of the plants (incorporated) while microcapsules were applied through irrigation in small basins around each plant. Carbofuran (as Furadan ® ) at the rate of 5.5 g a.i. per sq. m. was also applied using the same method. There were four treatments, including the control, repli- cated three times. The soil type was clay loam. Total num- ber of plants was 144. Nematode control performance of cadusafos, on an overall mean of 3 years, was high, whereas yields were signi cantly increased between 20.7- 21.9%. The pro t:treatment cost ratio for this nematicide reached four while no chemical residues were found in the fruit. Carbofuran was less effective than cadusafos in controlling the nematodes or increasing yields, under the conditions of this trial. 499 Economic impact of resistant tomato cultivars as an alternative to methyl bromide to control Meloidogyne javanica Francesco Xavier S ORRIBAS 1 ; ¤ , César O RNAT 2 , Soledad V ERDEJO -L UCAS 3 and Magda G ALEANO 3 1 ESAB 2 UPC, Comte d’Urgell, 187. 08036 Barcelona, Spain 3 IRTA, crta. Cabrils s/n, 08348 Cabrils, Barcelona, Spain ¤ francesc.xavier.sorribas@upc.es The economic impact of resistant tomato was evaluated in a plastic house infested with the nematode for three consecutive growing seasons starting in 1999. Treatments included susceptible (cv. Durinta) and resistant (cv. Monika) tomato cultivated in methyl bromide fumigated soil or in soil infested with Meloidogyne javanica . Methyl bromide was applied at a rate of 75 g/m 2 in October 1998 at a cost of 2.44 euros/m 2 . Tomatoes were cultivated from March to July, and there were 2.9 plants/m 2 . Each treatment was replicated four times. Nematode densities were determined at the beginning and end of each crop. Yield was assessed in eight plants/plot weekly for 6 weeks. Initial densities were 480 and 660 second stage juveniles (J2)/250 cm 3 soil, and changed to 10 356 and 190 J2/250 cm 3 soil after growing susceptible and resistant tomato, respectively, for three consecutive seasons. The average net pro t of cropping resistant tomato in infested plots was 30 000 euros/ha per season with respect to the susceptible cultivar in nematode infested plots, and 10 600 euros/ha per season with respect to the resistant cultivar in fumigated plots. The average net loss by cropping susceptible tomato in infested plots was 21,200 euros/ha with respect to those cropped in fumigated plots. 298 Nematology</p>
<p>Poster sessions 500 The effect of some legumes on stimulating egg-hatch to reduce densities of soybean cyst nematode Satoshi A IBA National Agricultural Research Center Nematology Laboratory, 3-1-1 Kannondai, Tsukuba, Ibaraki, 305-8666, Japan aiba@affrc.go.jp Hatching of soybean cyst nematode, Heterodera glycines , is stimulated by legume root-exudates. Non-host legumes also secrete these substances and can be used to decrease soil egg-densities. Root exudates of soybean, azuki bean, kidney bean, peas, two red clovers, white clover, alfalfa, sun hemp, Chinese milk vetch, sweet pea, lupine and mimosa were tested for stimulating egg-hatch. Kidney bean was the most effective legume and stimulated hatching of 66% of eggs assayed. The nematode reproduced on soybean, azuki bean, kidney bean and Chinese milk vetch. The non-host sun hemp stimulated 58.8% egg-hatch and was the most effective in reducing soil egg-densities. Alfalfa, mimosa and pea did not stimulate hatching. In eld plots the cultivation of sun hemp ( Crotalaria juncea and C. spectabilis ) or red clover decreased soil egg-densities by 57-64% compared to fallow control plots. Parasitic fungi attacked 14.9-18.1% of eggs present in susceptible or resistant soybean eld plots and 30.6-43.6% in egg-hatch stimulating legume eld plots. 501 Comparison of physical and chemical methods of controlling Ditylenchus dipsaci in garlic crops M. Fe A NDRES 1 ; ¤ and Javier C ABRERA 2 1 Dpto Protección Vegetal, Centro de Ciencias Medioambientales, CSIC, Serrano 115, Madrid 28006, Spain 2 Dpto Producción Vegetal, E.U.I.T.A. Universidad de Castilla-la Mancha Ronda de Calatrava s/n, 13004 Ciudad Real, Spain ¤ mafay@ccma.csic.es The effectiveness of soil solarisation and oxamyl applications against Ditylenchus dipsaci on garlic crops were evaluated under eld conditions in Central Spain. Oxamyl treatments were: dipping garlic cloves in water solution of Vydate at 3 ml/kg and at 1.5 ml/kg doses, and Vydate added in granule formulation (0.8 g/m) to the furrows at planting time. All treatments achieved a signi cant reduction in the rate of disease progress and the nal incidence of plant death by D. dipsaci , which resulted in a signi cant improvement of garlic yields. Soil solarisation for 8 weeks resulted in the reduction to undetectable levels of the nematode in the upper 20 cm layer of soil, even in heavily infested soils. Rates of disease progress were greatly reduced in solarised plots, with yield increments of 50-140% over the unsolarised control plots. Soil solarisation was also highly effective in a second consecutive crop of garlic, with signi cant improvements in yield and garlic quality. 502 Hot water drench treatments for the control of Radopholus similis in Rhapis and Fishtail palms Albert A RCINAS 1 ; ¤ , Brent S IPES 2 , Arnold H ARA 3 and Marcel T SANG 4 1 University of Hawaii at Manoa, Dept of Plant and Environmental Protection Sciences, 3190 Maile Way, St John Lab 313, Honolulu, HI 96826, USA 2 CTAHR, Dept of Plant and Environmental Protection Sciences, 3190 Maile Way, Honolulu, HI 96826, USA 3 Beaumont Agricultural Research Center, 461 W. Lanikaula Street, Hilo, HI 96720, USA 4 CANFRM, University of Hawaii, Hilo, 200 W. Kawili Street, Hilo, HI 96720, USA ¤ arcinas@hawaii.edu Exporters of potted nursery stock face strict quarantine regulations against Radopholus similis , the burrowing nematode (BN). Currently no quarantine treatments to disinfest plants of BN are approved. Therefore, hot water drench treatments were investigated for possible quarantine utility. Rhapis excelsa and Caryota mitis palms were inoculated with 5000 mixed life stages of BN 14 weeks prior to treatment. Hot water drench treatments were applied at 50 ± C for 0-16 min. In Rhapis palms, a moderately good host, a 16 min hot water drench achieved 99.6% mortality of BN. In Fishtail palms, a poor host, all treatments longer than 10 min at 50 ± C achieved 100% nematode mortality. Probit regression estimates were used to estimate LT 99 , resulting in 16.9 and 10.3 min for Rhapis and Fishtail, respectively. However  2 goodness-of- t tests for deviation from observed data was signi cant (  2 D 21 : 136, df D 3, P < : 0001 / for Rhapis. The high ef cacy of hot water drenches for the control of BN is approaching the Probit 9 standard of 99.9968% mortality required for United States Department of Agriculture approval as a quarantine treatment. 503 Forage pearl millet for the control of Pratylenchus penetrans and potato early dying disease Vol. 4(2), 2002 299</p>
<p>Integrated management (500-534) Guy B ÉLAIR ¤ , Yvon F OURNIER , Nathalie D AUPHINAIS and O.P. D ANGI Agriculture and Agri-Food Canada, 430 Gouin Blvd., St-Jean-sur-Richelieu(Quebec), J3B 3E6, Canada ¤ belairg@em.agr.ca Root-lesion nematode Pratylenchus penetrans causes yield losses in potato elds in Quebec. In some areas, it has been found associated with Verticillium dahliae and the potato early dying disease (PED). Under eld conditions, we evaluated forage pearl millet (FPM) as a rotation crop for controlling nematode populations, reducing PED symptoms and potato yield losses. In 1999, a 1-year crop rotation experiment was established on three commercial elds and where potato cv. Superior was grown the following year. FPM signi cantly reduced by 89% the number of P. penetrans in the soil and increased by 11% the subsequent potato yield when compared to oats. In 2000, again on a commercial potato eld, we assessed the usefulness of combining FPM rotation with preplant soil fumigation (fall in-furrow application of metham sodium 148 l/ha). The three following treatments were made: 1/rye C fumigation, 2/FPM alone, 3/FPM C fumigation. FPM alone performed as good as the rye C fumigation treatment. FPM C fumigation treatment reduced by 98% P. penetrans soil populations, reduced by 69% PED symptoms and increased by 31% the subsequent potato yields when compared to rye C fumigation. 504 Integrated and ecological nematode management in Canary Island crops Antonio B ELLO 1 ; ¤ , María A RIAS 1 , Miguel E SCUER 1 , J. Antonio L ÓPEZ -P ÉREZ 1 , Avelino G ARCÍA -Á LVAREZ 1 , Javier L ÓPEZ -C EPERO 2 , Ildefonso A COSTA 1 and Rafael S ANZ 1 1 Dpto Agroecología, CCMA, CSI, Serrano 115 dpdo, 28006 Madrid, Spain; 2 Cooperativa Nuestra Señora de Abona, 38589 Arico, Santa Cruz de Tenerife, Spain ¤ antonio.bello@ccma.csic.es The Canary Islands are characterised by Mediterranean and subtropical climatic conditions, its seasonal nature with hot summers and mild winters represents an eco- tone between temperate and tropical regions. Integrated and ecological nematode management are analysed. For the most part, Mediterranean agrosystems are represented by potato, vegetables, citrus and fruit trees and vineyards. Coastal environments are largely represented by bananas (‘plátanos’) and horticultural crops under cover. The main nematological problems in order of their economical im- portance are: root-knot ( Meloidogyneincognita and M. ja- vanica ), cyst ( Globodera pallida and G. rostochiensis ), virus vector ( Longidorus, Paratrichodorus, Trichodorus and Xiphinema ), endoparasitic ( Pratylenchus goodeyi ), citrus ( Tylenchulus semipenetrans ) and ectoparasitic ne- matodes (Criconematidae, Hoplolaimidae and Tylenchi- dae). It is also indicated that the environmental charac- teristics of the Canary Islands climate and soil conditions permit the design of integrated and ecological production systems based fundamentally on the use of non-chemical alternatives such as crop rotation and fallow, soil amend- ments, biofumigation, plantation date and other cultural practices, sanitation, plants grown on natural substrates, the use of resistant varieties, grafting, biological control agents and solarisation. These alternatives prevent pest and diseases from becoming serious problems and obtain high quality agricultural products. 505 Non-chemical alternatives for the control of Meloidogyne incognita in Uruguay Leonardo DE L EÓN 1 ; ¤ , J. Antonio L ÓPEZ -P ÉREZ 2 and Antonio B ELLO 2 1 Dpto Agricultura, Rel-UITA, W. Ferreira Aldunate, 1229, C.P. 11.100, Montevideo, Uruguay 2 Dpto Agroecología, CCMA, CSIC, Serrano 115 dpdo, Madrid, Spain ¤ leonardo@rel-uita.org Among other problems caused by soil-borne pathogens, losses are greatest from the root-knot nematode Meloi- dogyne incognita in Uruguay intensive horticulture. Sev- eral non-chemical alternative control methods have been tested: biofumigation, using various organic amendments and green manures, resistant varieties, plant covers, trap crops and other crop techniques, all within a programme of integrated production. Resistant varieties are used in tomato crops; however, we must take into account that re- sistance can be inef cient when soil temperature is higher than 27 ± C and particularly when virulent nematode po- pulations exist. These alternatives are being applied to several crops and production zones in Uruguay, gener- ally with similar, and sometimes even better, effective- ness than conventionalphytosanitary products. Moreover, farmers nd no dif culty in applying these alternatives since they have been developed through a participative re- search process. 300 Nematology</p>
<p>Poster sessions 506 Reaction of bacterial-feeding nematodes to pig manure with antibiotic and manure without antibiotic Ewa D MOWSKA ¤ and Krassimira I LIEVA -M AKULEC Institute of Ecology, Polish Academy of Sciences, Dziekanow Lesny, 05-092 Lomianki, Poland ¤ edmowska@.poczta.onet.pl The study was carried out in three experimental plots in grassland (10 m 2 each) treated in three different ways: i ) 100 l of water, ii ) 100 l of manure from pigs fed on forage with antibiotic ZnBacitracin, iii ) 100 l of manure from pigs fed on forage without antibiotic. Nematode communities were studied 6 and 12 weeks, and 10 months after the treatment. In our study, bacterial-feeding nematodes belonged to ve orders: Areolaimida, Dorylaimida, Monhysterida,Rhabditidaand Teratocephalida. In every treatment, on all sampling occasions nematodes belonging to the order Rhabditida visibly dominated. The following parameters were used for evaluation of the effect of two kinds of manure on bacteriovores: i ) total abundance of bacterial-feeding nematodes, ii ) Diversity index (H 0 gen), iii ) Maturity index (MI), iv ) number of genera in order Rhabditida. Abundance and dominance of particular genera belonging to Rhabditida in three plots were also analysed. Obtained results showed that the values of analysed parameters as well as the response of particular genera of Rhabditida differed in three plots: untreated, and treated with two kinds of manure, from pigs fed on forage with and without antibiotic. 507 Heterodera glycines distribution within a eld in no-till production over time Patricia A. D ONALD ¤ , Kenneth A. S UDDUT H and Newell R. K ITCHEN USDA ARS 605 Airways Blvd, Jackson, TN 38301 and USDA ARS 269 Ag Engineering Bldg, University of Missouri, Columbia, MO 65211, USA ¤ pdonald@ars.usda.gov Heterodera glycines (SCN) is a major pest of soybean causing signi cant yield losses when present and when management techniques to reduce egg population density are not used. A study investigated the distribution of SCN at planting and harvest in a claypan soil eld in central Missouri under no-till soybean production. Comparisons were made of the nematode distribution in 1999 and 2001, years of soybean production. Nematode distribution in the 2 years was compared to yield, topsoil thickness, elevation, and soil nutrient maps. Nematode distribution was most closely correlated with topsoil thickness ( i.e ., depth to the claypan). Lower H. glycines population density occurred in areas with shallow topsoil thickness. 508 Computer modeling of integrated control of potato cyst nematodes Martin J. E LLIOTT 1 ; ¤ , James W. M CNICOL 2 , David L. T RUDGILL 1 and Mark S. P HILLIPS 1 1 Scottish Crop Research Institute, Dundee, DD2 5DA, Scotland, UK 2 Bioinformatics and Statistics Scotland, Scottish Crop Research Institute, Dundee, DD2 5DA, Scotland, UK ¤ mellio@scri.sari.ac.uk A computer program modelling the integrated manage- ment of PCN has been developed based on equations cali- brated and validated with eld trial data. Population trends and damage are presented for up to six rotations, and the control measures can be varied for each potato crop. Cur- rently, it is an effective educational tool for demonstrating the effects of soil type and of varying rotation length, ne- maticide effectiveness and the resistance and/or tolerance of the cultivar being grown. To develop its predictive po- tential, the relationship between PCN population density, damage and multiplication rates are being calibrated for speci c elds. Nematicide effectiveness and rates of PCN population decline between potato crops are also being determined. Slider controls are used to vary the parameter estimates to produce a least squares ‘best t’ line and the new parameters are inserted into the main management program. The advantage of this approach is that relatively crude/variable data, based on a small number of samples, can be used to calibrate the models and avoid ’conver- gence’ problems. 509 The interaction between an arbuscular mycorrhizal fungus and migratory endoparasitic nematodes in Musa genotypes differing in host plant response Annemie E LSEN ¤ , Rony S WENNEN and Dirk D E W AELE Laboratory of Tropical Crop Improvement, K.U.Leuven, Kasteelpark Arenberg 13, 3001, Leuven, Belgium ¤ annemie.elsen@agr.kuleuven.ac.be Vol. 4(2), 2002 301</p>
<p>Integrated management (500-534) Arbuscular mycorrhizal fungi (AMF) are obligate sym- bionts of plants that biotrophically colonise the root cor- tex and develop an extramatrical mycelium which helps the plant acquire water and mineral nutrients from the soil. AMF also may protect plants against soil-borne pathogens, including nematodes. Two Musa genotypes, i.e. , Grande Naine as susceptible genotype and Pisang Jari Buaya as resistant genotype, were selected for their known host plant response to two nematode species. The migratory endoparasites, Radopholus similis and Praty- lenchus coffeae , are important pests in Musa . The AMF can protect both Grande Naine and Pisang Jari Buaya against these nematodes, since nematode reproduction was signi cantly suppressed by the AMF. In the case of P. coffeae the AMF was able to reduce the damage in the roots, caused by the nematodes. For R. similis , no reduc- tion of damage was observed. It appears that the nema- todes reduced the frequency of mycorrhizationwithout re- ducing the intensity of the mycorrhizal association. Myc- orrhization resulted in a signi cant better plant growth, even in the presence of R. similis and P. coffeae. 510 The challenge towards integrated control of root-knot nematodes for developing agriculture in South Africa Hendrika F OURIE ¤ , Michael Jacobus S CHOEMAN , Mbaliyethu Benedicta M TSHALI , Caroline Makgabo L ESWIFI , Hendrik Frederik R IEKERT and Alexander Henrique M C D ONALD ARC-Grain Crops Institute, Private Bag X1251, Potchefstroom, 2520, South Africa ¤ driekie@igg2.agric.za Root-knot nematodes are omnipresent in most resource- poor areas of South Africa. A survey conducted in ve provinces con rmed the extent of this problem, while demonstrations of signi cant crop yield losses also accentuated an urgent need for development and application of integrated, effective nematode management strategies to enable sustainable food production. On- farm trials, where alternative, low-cost nematode control strategies were evaluated, revealed treatments with a fair potential for implementation by resource-poor farmers to reduce root-knot nematode numbers signi cantly. A signi cant reduction of root-knot nematodes by means of crop rotation, using crops popular to small-scale farmers in a particular cropping sequence was established in a multi-seasonal microplot trial. Resistance screening of dry bean and cowpea genotypes supplied additional, valuable information on the application of increased resistance for the prevention of root-knot nematode population build-up in cropping systems. Finally, use of a cover crop such as Vetiver grass can contribute signi cantly to root-knot nematode control, particularly where livestock forms an integral part of a farming system. Integration of some or all of these control strategies that are currently available can already contribute signi cantly to household food security of developing farmers with minimal additional input costs and effort. 511 Grapevine management, virus vector nematode populations and GFLV: an approach to disease epidemiology Jesús F RESNO 1 ; ¤ , María A RIAS 2 and Antonio B ELLO 2 1 INIA-SGIT, Dpto Biotecnología, Ctra de la Coruña Km 7.5, 28040 Madrid, Spain 2 Dpto Agroecología, CCMA, CSIC, Serrano 115 dpdo 28006 Madrid, Spain ¤ jfresno@inia.es Factors affecting GFLV transmission in vineyards from the Canary Islands have been studied for more than 10 years. The special agricultural characteristic of grape crops in Lanzarote, La Palma, El Hierro and southern Tenerife, which use traditional methods of grapevine selection, have prevented the dispersal of the virus by nematodes. Moreover, no problems occur with nematodes in those vineyards growing on volcanic substrates except in Gran Canaria, because there vineyards are localised in the Laurisilva where high humidity exits. However, new crop techniques could contribute to an increase in infection, especially irrigation and non-controlled plants introduced in new plantations. Xiphinema index and X. italiae populations are increasing. Moisture in the soil and the steady year-round temperature on the island increase the viral infection. Besides, lm water is a good vehicle for nematode and viral dispersal, especially on slope farms with irrigation. Both vectors and GFLV are widespread in the whole archipelago, disseminated mainly in new plantations through infected rootstocks, as a consequence of the introduction of non-certi ed plants. The greatest focal points for both pathogens appeared in irrigated vineyards or areas with the highest soil moisture, where the viral infection is maintained over the years. 302 Nematology</p>
<p>Poster sessions 512 Meloidogyne incognita control by biofumigation plus solarisation on glasshouse pepper crops in the southeast of Spain M.M. G UERRERO 1 , A. L ACASA 1 ; ¤ , C. R OS 2 , P. G UIRAO 2 , A. B ELLO , J.A. L ÓPEZ -P EREZ 3 , M.A. M ARTÍNEZ 1 , M.C. M ARTÍNEZ 1 , N. B ARCELÓ 1 and J. T ORRES 1 1 Protección Vegetal, Centro de Investigación y Desarrollo Agroalimentario, CAAMA, c/Mayor s/n, 30.150 La Alberca – Murcia, Spain 2 FECOAM – Consejería de Agricultura, Agua y Medio Ambiente, C/Caballero, 13, 30.002 Murcia, Spain 3 Dpto de Agroecología, Centro de Ciencias Medioambientales, CSIC, C/Serrano 115 apdo 28.006 Madrid, Spain ¤ Alfredo.Lacasa@carm.es Meloidogyne incognita is one of the main soil borne pathogens in pepper glasshouses of the southeast of Spain. In this area pepper may be considered a monoculture grown over more than 90% of the 1800 ha total crop surface. Timing of the biofumigation-solarisation application as a nematode control method was assayed in commercial and experimental greenhouses. Ef cacy was evaluated by measuring the percentage of infected plants, average root-knot index and marketable yield in relation to methyl bromide (MB). When a mixture of fresh sheep manure (FSM) at 7 kg/m 2 and chicken manure at 3 kg/m 2 was used as an organic amendment applied from the end of August to the beginningof September, marketable yield (9.4 kg/m 2 in August and 12.0 kg/m 2 in September) was similar to that of MB (9.9 kg/m 2 in August and 12.2 kg/m 2 in September). However, the percentage of M. incognita infected plant was lower in biofumigation treatments. When applications were initiated at the beginning of October and November, biofumigationtreatments differed signi cantly from MB treatments in all the parameters measured. 513 Changes in nematode faunas under different short- and long-term management regimes Mike H ODDA 1 ; ¤ and Emma B ROOS 2 1 CSIRO Entomology, GPO Box 1700, Canberra ACT 2601, Australia 2 Farming Systems Research Centre, University of Western Sydney-Hawkesbury, Richmond NSW 2753, Australia ¤ mike.hodda@csiro.au Different trophic groups of soil nematodes were affected by both short-term and long-term agronomic practices in replicated trials at several sites in eastern Australia. In the short-term (2-3 years), tillage and residue management affected plant-parasitic nematodes ( Pratylenchus , Tylen- chorhynchus , Paratrichodorus , Paratylenchus ). Microbial feeding, substrate ingesting and certain predatory ne- matodes were more abundant and diverse in less cul- tivated soils, while fungivorous nematodes were more abundant and diverse in cultivated soils. Omnivorous nematodes showed few differences with cultivation but were less abundant where more organic residues were re- tained. There were more microbivores and they were con- centrated closer to the surface where residues were re- tained; fungivores, by contrast, were deeper in the soil. There were no differences in the Maturity Index. Over longer-terms (5-10 years), rotation from wheat to pas- ture decreased the abundance of most plant-parasitic ne- matodes ( Pratylenchus , Tylenchorhynchus , Criconemati- dae, Tylenchidae), but not Ditylenchus or Dorylaimoides , which increased. Helicotylenchus populations were un- changed. Fungivores, predators, omnivores and substrate ingesters were more abundant in continuouscropping;mi- crobivores and algal feeders more abundant after rotation. Short-term management practices such as cultivation and residue retention affect soil nematodes, and by implication the energy pathways in the soil, in different ways from longer term practices such as rotation. 514 Effect of hot-water treatment on nematode species composition and densities in plantain roots in short and long fallow (Central Province, Cameroun) Kim J ACOBSEN 1,§,* Stefan H AUSER 1 and Dirk De W AELE 2 1 IITA HFC, BP. 2008, Yaoundé (Messa), Cameroun § present address: INIBAP/CARBAP, BP. 12438, Douala, Cameroun 2 Laboratory of Tropical Crop Improvement, Catholic University of Leuven (K.U.Leuven), Kasteelpark Arenberg 13, 3001 Leuven, Belgium ¤ kimsarahjacobsen@hotmail.com Root nematodes were identi ed as a major cause of yield loss in plantains. The objective of this study was to determine the effects of plantain variety, fertiliser application, hot-water treatment (20 min at 52 ± C) of suckers before planting and fallow length, on the root damage parameters and nematode numbers in plantain roots. The experiment was set up on-farm as a randomised complete block design with 64 plots, each of 25 plants. Roots of ve plants per plot were sampled at 15 months Vol. 4(2), 2002 303</p>
<p>Integrated management (500-534) after planting. Preliminary results indicate that variety and fertiliser application had no signi cant effect on nematode numbers or root damage parameters. Hot-water treatment signi cantly reduced total nematode numbers in both fallow types, although fallow length had no signi cant effect on nematode numbers. Signi cantly higher root necrosis indices (RNI) were observed in plants in long fallow plots compared to plants in the short fallow plots. However, the total number of functional roots was signi cantly more in the long fallow plots, giving an overall signi cantly better health of the root system, as indicated by the non-damaged root index (NDRI D number of functional roots £ (100-RNI)). Hot-water treatment did not signi cantly reduce the RNI in the short fallow, although it did signi cantly increase the NDRI in both fallow types. 515 Sanitation ef cacy of a combined thermal lter press and vacuum dryer on potato cyst nematode and wild oat in the production of VEAS-Biosolids Christer M AGNUSSON 1 , Paul S AGBERG 2 and Bonsak H AMMERAAS 1 1 The Norwegian Crop Research Institute, Plant Protection Centre, Department of Entomology and Nematology, Høgskoleveien 7, N-1432 Aas, Norway 2 Vestfjordens Avløpsselskap (VEAS), Bjerkåsholmen 125, N-3470 Slemmestad, Norway The soil conditioner, VEAS-Biosolids, is produced through compression, heating and vacuum drying of sewage sludge at the VEAS wastewater treatment plant in Slemmestad, Norway. The sanitation ef cacy for potato cyst nematode (PCN), Globodera rostochiensis and wild oat, Avena fatua , was evaluated for the nal production step, the combined thermal lter press and vacuum dryer. Germ carriers, each carrying three nylon bags with 20 nematode cysts and one bag with 100 seeds of wild oat, were placed in three lter presses. Germ carriers were either exposed to sludge for 4 days, or kept dry before the test. The test pathogens were exposed to pressures of up to seven bars at 35 o C, followed by heating to 80 o C and vacuum at ¡ 0 : 92 bar during continued heating. Nematode vitality was studied by recording juvenile hatch, by vitality staining with New Blue R, and by recording nematode developmenton susceptible potato. Viability of wild oat was examined by tetrazolium test. There was a 100% ef cacy in the sanitation of PCN and wild oat. For both organisms pre-exposure to sludge seemed to reduce vitality and viability. The mechanism of sanitation may rely on an interaction between sludge toxicity, and the changes in temperature and pressure. 516 Nematode management in subsistence farming in Mexico Rosa H. M ANZANILLA -L ÓPEZ 16 Coleswood Road, Harpenden, Herts, AL5 1EQ, UK rosa.manzanilla-lopez@bbsrc.ac.uk Factors such as geography, climate, vegetation, biogeog- raphy and human settlement have contributed in de n- ing Mexican rural and socio-economic scenarios. Mexi- can agriculture has two main approaches: the campesino and the agro-industrial, both with contrasting character- istics related to production and management strategies against pests and diseases. In campesino and subsistence systems, low external-inputstrategies that have proved ef- fective in the management of the most common and im- portant plant-pathogenic species of nematodes in Mexico ( i.e ., Meloidogyne spp., Nacobbus aberrans , Pratylenchus spp. and Punctodera chalcoensis ), include production of plant and tree seedlings free of nematodes, physical con- trol methods, rotations, organic amendments, antagonis- tic plants, suppressive soils and maintenance of biodiver- sity. Most of these practices are considered to be envi- ronmentally friendly but, although subsistence agriculture can produce enough food to feed families or small com- munities, it may be adversely affected by socio-economic factors such as availability of good land, adequate water, migration, pressures on land use, shortened rotations, crop value and changes in cultural patterns, thus compromising sustainability. 517 Interactions between vinyl house tomato IPM measures for control of Meloidogyne incognita and Fusarium oxysporum f. sp. lycopersici Takayuki M IZUKUBO ¤ , T. T AKEHARA , K. I TO , S. A IBA and T. N AKAYAMA Nematology Laboratory, Department of Entomology and Nematology, National Agricultural Research Center, National Agricultural Research Organization, Tsukuba 305-8666, Ibaraki, Japan ¤ mizu@affrc.go.jp Hot water (HW), Pasteuria penetrans (PP), Glomus sp. R10 (Arbuscular mycorrhiza, AM) and an avirulent Fusarium oxysporum (AF) were applied to 2 m 2 vinyl house plots where Meloidogyne incognita and Fusarium 304 Nematology</p>
<p>Poster sessions oxysporum f. sp. lycopersici were present. The experiment used a 2 3 factorial design with three replicates to identify interactions between IPM measures. Untreated plots and fumigated (D-D 52% C chloropicrin 40%) plots were the controls. Tomato seedlings were planted and grown from March to July 2001 (15 weeks). HW completely suppressed Fusarium wilt of tomato. HW and PP-AM suppressed root galling and juvenile population ( P < 0 : 01 / , with synergistic interactions between HW and PP- AM ( P < 0 : 05 / . When applied together HW £ PP-AM root galling was similar to that of the fumigated plots. AF applied with HW was associated with increased galling; however, this effect diminished when AF, HW, and PP- AM were applied together. HW and PP-AM yielded the most fruit ( P < 0 : 01 / without an interaction between the two measures. When applied together, HW £ PP-AM and HW £ AF £ PP-AM had yields 28 and 39% greater than the untreated controls, respectively. The interaction between HW and PP-AM, as well as increased galling associated with AF and HW, will be discussed. 518 Mechanisation has added bene ts in nematode management in tea Keerthi M OHOTTI 1 ; ¤ , Maithri L IYANAGE 2 and Nissanka N AVARATNE 1 1 Tea Research Institute of Sri Lanka, Talawakele, 22100, Sri Lanka 2 Great Western Estate, Talawakele, 22100, Sri Lanka ¤ mohottik@yahoo.com Replanting has paramount importance in sustaining the productivity of tea. This involves uprooting old tea followed by rehabilitation of soils using grasses. Mechanical uprooting of old tea bushes has recently been introduced to the industry owing to shortage of workers, cost factor and timing of replanting operation etc ., over conventional manual uprooting. The present exercise compared the effect of mechanical and manual uprooting on management of populations of the root lesion nematode, Pratylenchus loosi in old tea elds. Mechanical uprooting left signi cantly low amounts of root fragments and the soils possessed low residual populations of P. loosi compared to that in manually uprooted soils. The growth of rehabilitation grasses was superior in mechanically uprooted eld. It resulted in a greater proportion of organic matter addition and signi cant elevation of densities, activation and establishment of nematode biocontrol agents, especially free-living nematodes, in the soil. Improvements in soil biological and chemical properties were also seen. The newly planted tea in mechanically uprooted elds exhibited signi cantly greater root biomass. 519 The effect of crop rotation and tillage systems on soil nematode trophic structure Eduardo M ONDINO , Eliseo C HAVES and Guillermo S TUDDER Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata, C. Correo 276, 7620 Balcarce, Argentina mendo@scientist.com The effect of the use of crop – pasture rotation and tillage systems (conventional tillage – CT and no-tillage – NT) on soil nematode communities was studied during 1 year in a long-term crop rotation and tillage system eld experiment on a Typic Argiudoll at Balcarce, Argentina. Four seasonal samplings were done and nematodes were extracted from soil using the centrifugation- otation technique. The trophic structure was dominated by bacteria feeder and plant feeder nematodes and the highest nematode abundance was found in winter. The highest plant feeder nematode abundance was shown in pasture in autumn ( P < 0 : 05 / , followed by crop – pasture rotation. Tillage system did not signi cantly affect the abundance of such trophic group. The fungivores abundance was lowest in crop rotation under NT in autumn. The bacteriovores were lowest in the pasture in spring and were not affected by the tillage system. The maturity index (MI) was affected by treatments in spring ( P < 0 : 05 / . The pasture and crop – pasture rotation under CT showed the highest MI value. The diversity index (H 0 ) was affected by the treatments in winter and spring ( P < 0 : 05 / . The H 0 was lowest for crop – pasture rotation under CT in winter. The H 0 was lowest under pasture in spring. A higher nematode diversity richness was detected in comparison to previous reports from this region. 520 The harmful in uence of associations of nematodes and mono- and complex virus infections on potato plants and the effectiveness of ecological safe control methods of these pathogens S. N ASROLLANEJAD 1 , O.O. B ELOSHAPKINA 1 and N.D. R OMANENKO 2,* 1 K.A. Timiriyaziev Agricultural Academy, Moscow 2 Institute of Parasitology of Russian Academy of Sciences, Leninskii prosp. 33, Moscow, Russia Vol. 4(2), 2002 305</p>
<p>Integrated management (500-534) ¤ nd_romanenko@mail.ru The harmful in uence of associations of longidorid and trichodorid nematodes and four viruses (TRV, X, S, M) and associations from two to six virus and nematode components exercised considerable and reliable in uence on the dynamics of growth (height and number of shoots) and yield of tubers of potato plants. The largest synergetic in uence of complex trichodorid and longidoridnematodes and virus infections was found in cases of four, ve and six virus and nematode components. The antivirus action of two biopesticides (planrhiz and trichodermin) and six physiological active agents (narciss, immunocytophyt, F- 760, F-1153, immunal, and nikfan) by spraying above- ground organs of potato plants in eld conditions in comparison with untreated control were studied. Different nematicidal and antivirus actions were found in most bioagents that exercised positive in uence on yield of potato tubers and dynamic growth of potato plants. 521 Population growth rates of two fungal-feeding nematodes, Filenchus misellus (Tylenchdiae) and Aphelenchus avenae (Aphelenchidae), on ten fungal isolates Hiroaki O KADA ¤ and Ikuo K ADOTA National Agricultural Research Center for Tohoku Region, Arai, Fukushima City, 960-2156, Japan ¤ hokada@affrc.go.jp To clarify differences in reproduction characteristics be- tween Filenchus misellus (family Tylenchidae) and Aphe- lenchus avenae (Aphelenchidae), their population growth rates were measured after 40 days incubation at 25 o C on ten isolates of fungi representing nine species. Fi- lenchus misellus growth rates were large on Agaricus bis- porus, Chaetomium cochlioides, Chaetomium globosum , Chaetomium funicola , Coprinus cinereus, Pleurotus os- treatus and Rhizoctonia solani , and small on Pythium ulti- mum , Fusarium oxysporum f. sp . conglutinans and Fusar- ium oxysporum f. sp . cucumerinum . In contrast, A. ave- nae growth rates were large on P. ultimum , R. solani , F. oxysporum f. sp. conglutinans, F. oxysporum f. sp. cuc- umerinum and A. bisporus , and small on C. cochlioides, C. globosum, C. funicola , C. cinereus and P. ostreatus . These results suggest that F. misellus , which reproduces well on saprophyticfungi and mushrooms, may occupy an ecological niche different from that of A. avenae , which reproduces well on plant-pathogenic fungi, although both nematode species did well on R. solani and A. bisporus. 522 Soil solarisation, nematicide and chicken compost for root-knot nematode control in carrot in Brazil Claudio M.G. O LIVEIRA 1 ; ¤ , Roberto K. K UBO 1 , Mario M. I NOMOTO 2 , Flávia R.A. P ATRÍCIO 1 , Osvaldo C ABRAL 3 and Benedito C. B ARROS 1 1 Instituto Biológico, Caixa Postal 70, Campinas, SP, 13001-970 Brazil 2 Universidade de São Paulo, Escola Superior de Agricultura ‘Luiz de Queiroz’, Caixa Postal 09, Piracicaba, SP, 13418-900 Brazil 3 EMBRAPA Meio Ambiente, Caixa Postal 69, Jaguariúna, SP, 13820-000 Brazil ¤ colive@scri.sari.ac.uk A eld experiment was performed in sandy soil, naturally infested with Meloidogyne incognita and M. javanica , in Piracicaba, SP, Brazil, to assess the effectiveness of soil solarisation, chicken compost (20 t/ha), carbofuran 100G (40 kg/ha), and combinations of these treatments for the control of root-knot nematodes in carrot cv. Aline. Soil solarisation was performed over 69 days during the warmest months of summer of 2000/2001, using a 100 ¹ m polyethylene plastic lm as soil covering. The soil temperature in solarised plots was 8-12 ± C higher than in the nonsolarised. Maximum soil temperatures were recorded in solarised soil combined with chicken compost and reached 77, 56 and 46 ± C, at depths of 5, 10 and 20 cm. Population densities of M. incognita and M. javanica were controlled by both soil solarisation alone and combined with chicken compost or carbofuran. Carrot cv. Aline yield was signi cantly increased by combination of solarisation and chicken compost plus nematicide application before planting. 523 Current management strategies employed against the reniform nematode ( Rotylenchulus reniformis ) in cotton production in Louisiana, USA Charles O VERSTREET 1 , Edward C. M C G AWLEY 2 and Boyd P ADGETT 3 1 LSU AgCenter Research and Extension, Department of Plant Pathology and Crop Physiology, 302 Life Sciences Building, Baton Rouge, LA 70803, USA 2 Department of Plant Pathology and Crop Physiology, 302 Life Science Building, Baton Rouge, LA 70803, USA 306 Nematology</p>
<p>Poster sessions 3 Northeast Research Station, 212 Macon Ridge Road, Winnsboro, LA 71295, USA ¤ coverstreet@agctr.lsu.edu Reniform nematode has become a major pest of cotton in Louisiana during the past decade. Since 1990, 40% of the 18 477 samples processed by the Nematode Advisory Service revealed detectable levels of reniform nematode. Nematicides and crop rotation are the primary methods of management. In-furrow application of aldicarb at 0.59 kg/ha has been a producer standard since the 1980s. Based on 35 eld trials, plots receiving an in-furrow application of aldicarb (0.59 kg/ha) produced an average 262 kg/ha more seed cotton than non-treated plots. The addition of 1,3 dichloropropene at 28 l/ha to the producer standard rate of aldicarb increased yields over the grower standard by 326 kg/ha in six eld trials. Approximately 25-30% of the cotton crop is rotated to a non-host or resistant crop such as corn, grain sorghum, or soybean. Only ve of the 69 soybean varieties recommended for Louisiana have been reported as resistant against this nematode. Populations of reniform nematode averaged 2682 per 500 cm 3 of soil in 217 elds in Rapides Parish after cotton followed by 1 year of corn. Populations of reniform nematode averaged 9558 per 500 cm 3 in 158 elds after corn followed by 1 year of cotton. 524 Biological and chemical control of Meloidogyne incognita and its effect on soil micro ora and growth of Psidium guajava seedlings in Zulia State, Venezuela Evelyn P ÉREZ -P ÉREZ 1 ; ¤ , Ana Maria C ASASSA -P ADRÓN 2 ; 3 , Merylin M ARIN 3 , Casilda G ONZÁLEZ 1 , Dubia C HIRINOS 1 and Luis S ANDOVAL 2 1 Centro Frutícola del Zulia-CORPOZULIA, Maracaibo, Venezuela 2 Universidad del Zulia, Facultad de Agronomía, Instituto de Investigaciones Agronómicas 3 Departamento de Botánica, Maracaibo, Apto 15205, Venezuela ¤ evelyncpp@cantv.net The effects of Trichoderma harzianum , Paecilomyces lilacinus and carbofuran on Meloidogyne incognita and fungal and bacterial populations in the rhizosphere, rhizoplane, roots and soil were studied on Psidium guajava seedlings. The effects of the nematode on fresh root weight (FRW), fresh aerial weight (FAW) and dried aerial weight (DAW) were also evaluated at the Centro Frutícola del Zulia-CORPOZULIA. Sixty-day-old seedlings were transplanted to 2.5 dm 3 bags of sterilised sandy loam inoculated with two eggs C second stage juveniles/cm 3 soil. Samples were collected at 30 and 60 days. We found statistically signi cant differences between treatments in all variables studied except for fungi in root samples and bacteria in rhizosphere and roots. The lowest nal population level and multiplication rates were recorded from the carbofuran treatment, as well as the highest values for FRW, FAW and DAW. However, this treatment also caused the least development of fungal and bacterial colonies in the rhizosphere, rhizoplane and roots. The treatments studied showed a low capacity for controlling M. incognita on guava seedlings. 525 Distribution of Globodera rostochiensis in the central region of Russia and new control methods I.O. P OPOV and N.D. R OMANENKO ¤ Institute of Parasitology, Russian Academy of Sciences, Leninskii pr. 33, Moscow, 117071, Russia ¤ nd_romanenko@mail.ru Considerable infection of potato plantation by Globodera rostochiensis was found in industrial and scienti c elds in different regions of Russia (Karelia, Moscow, Vladimir and Voronezh regions). Cysts of G. rostochiensis were found at seven of 20 investigated potato crops. The in uence of biological agents and bioactive substances ( i.e. , biologicalpesticides, planrhiz and trichodermin;new biologically active strains of Bacillus , Pseudomonas and others; chitin containing substances narciss and agrochyt; and new Russian physiologically active substances, oligophurostanozid, immunocytophyt, compactin and lovastatin) on number and life activity of G. rostochiensis cysts in soil and on potato plants growth and yield, after treating tubers and plants with these biologically active agents, was studied. Nematicidal activity of three physiologically active substances (two inhibitors, compactin and lovastatin, and one resistance stimulator, immunocytophyt) was studied in experiments in vitro . Inhibitors of plant growth (compactin and lovastatin) demonstrated stimulating in uence on the release of the infective juveniles from G. rostochiensis cysts. 526 Development and transfer of technology for bio-intensive nematode management in Southern India M.S. R AO and P. Parvatha R EDDY Vol. 4(2), 2002 307</p>
<p>Integrated management (500-534) Division of Entomology and Nematology, Indian Institute of Horticultural Research, Bangalore, India Increased demand in the domestic and international mar- ket for the horticultural produce has led to intensive culti- vation of horticultural crops in various states of India. This has resulted in the increase of root-knot nematodes ( Me- loidogyne spp.) to an alarming extent affecting adversely the crop growth and productivity. No single method of control of nematodes and no single component of man- agement of nematodes was effective in the management of nematodes on any horticultural crop on a sustainable ba- sis. Biocontrol agents such as Paecilomyces lilacinus , Tri- choderma harzianum , Verticillium chlamydosporium and Pasteuria penetrans are not effective individually in the management of nematodes under eld conditions. Simi- larly, endomycorrhiza ( Glomus mosseae or G. fascicula- tum ), botanicals (neem or castor or pongamia cakes) or any trap crop, antagonistic plant or any cultural practice is not effective individually in the eld. Hence, we in- vestigated the possibilities of integration of these compo- nents for the management of the nematodes on horticul- tural crops on a sustainable basis. The investigationshave resulted in the development of integrated nematode man- agement strategies of economically important nematodes of this region by integrating biocontrol agents, botanicals and endomycorrhizaeunder eld conditions by exploiting the synergistic interaction between P. lilacinus C neem cake C G. mosseae ; P. lilacinus C castor cake C G. fas- ciculatum ; T. harzianum C neem cake C G. mosseae ; V. chlamydosporium C neem cake C G. mosseae combina- tions. The data on the adoption of the technology, percent increase in the yield and the reduction in the use of chem- icals is presented. 527 In uence of tillage on soybean pathogens in Illinois John R USSIN ¤ and Jason B OND Plant, Soil and General Agriculture, Southern Illinois University, Mailcode 4415, Carbondale, IL 62901-4415, USA ¤ jrussin@siu.edu Fusarium solani f. sp. glycines (FSG), the causal agent of soybean sudden death syndrome (SDS), and Heterodera glycines are the two most important soybean pathogens in Illinois. Sudden death syndrome is generally more severe in areas with greater soil compaction and/or waterlogged conditions. At two locations, the effects of three tillage practices on pathogen populations and foliar severity of SDS were evaluated. Treatments were fall subsoiling (depth of 46 cm), convention tillage, and no tillage. In each treatment, 16 varieties were planted in 2000 and 32 varieties were planted in 2001. The varieties varied with regards to SCN and SDS resistance. In both years, SCN reproduction was higher on SCN-susceptible varieties. Egg densities of SCN were higher in plots receiving subsoiling treatments at one site in 2000 and at both sites in 2001. Across varieties, subsoiling reduced the severity of SDS at both locations in 2000 and 2001. Root colonisation by FSG differed among varieties but was not affected by the tillage practices. In 2000 and 2001, soybean yield was higher in plots receiving the subsoiling treatment. 528 Crop rotation options for management of Pratylenchus neglectus in cereal-based production systems in Western Australia Shashi S HARMA ¤ , Sean K ELLY and Robert L OUGHMAN Department of Agriculture, Baron Hay Court, South Perth WA 6151, Australia ¤ ssharma@agric.wa.gov.au Pratylenchus neglectus is a key nematode parasite of cereals in Western Australia. To identify crop rotation options for nematode management, cultivars of barley (Stirling), oat (Dalyup), wheat (Nyabing), canola (Dunkeld and Karoo), chickpea (Heera), faba bean (Fiord), eld pea (Dundale) and lupin (Merrit) were sown in 1999 in 40 £ 1.8 m plots in a randomised block design with six replications in a nematode-infested eld. Nematode numbers in soil before planting and in roots after 10 weeks were assessed. Wheat cv. Machete was the highly susceptible check. All the plots in 2000 were sown with wheat cv. Cunderdin, and in 2001 with the same crop as in 1999. Nematode data were log-transformed for analysis. Field pea and faba bean supported signi cantly fewer nematodes than other crops. Previous year crops signi cantly in uenced nematode infestation and the fewest were extracted from plants in plots previously planted to faba bean and most in plots previously planted to wheat. In 2001, infestations were least in faba bean and eld pea and greatest in chickpea, oats and canola cv. Karoo. Faba bean and eld pea were identi ed as suitable crop options to aid in the rotational management of P. neglectus . 308 Nematology</p>
<p>Poster sessions 529 Trap cropping of potato cyst nematodes using resistant Solanaceae potato clones Susan J. T URNER ¤ and Trevor J.G. M ARTIN Applied Plant Science Division, Department of Agriculture and Rural Development for Northern Ireland, Newforge Lane, Belfast BT9 5PX, UK ¤ Sue.Turner@dardni.gov.uk In recent years the levels of Globodera pallida in potato land has been steadily increasing, such that some land is now considered unproductive for continued commercial potato production. The concept of using Solanaceae potato clones as biological control agents for PCN was investigated. The criteria for such clones were that they have full resistance to all known PCN pathotypes (both G. rostochiensis and G. pallida ), have the ability to stimulate high levels of PCN hatch, and be tolerant to high levels of PCN invasion. A 3-year eld trial was undertaken that evaluated clones that ful lled these criteria. These clones included wild potato species from South America, advanced breeders lines and potato cultivars. Overall, the test clones signi cantly enhanced the annual natural decline rate of ca 19% under Northern Ireland conditions, with a range from 26 to 54%. Comparison of yield, when nematicides were applied, con rmed that several clones could tolerate extremely high levels of PCN (up to 1000 eggs g ¡ 1 soil). These trials have con rmed that the basic principle of using such material is a sound way of enhancing PCN decline, and may be an attractive alternative for cleaning up land under the ‘set aside’ scheme, or for organic potato production. 530 Effect of applied phosphorus on population density of root lesion nematode ( Pratylenchus neglectus ) Vivien A. V ANSTONE 1 ; ¤ , Michelle H. R USS 1 ; 2 , Alison F RISCHKE 3 and Sharyn P. T AYLOR 2 1 University of Adelaide, Department of Plant Science, PMB 1, Glen Osmond, 5064, South Australia, Australia 2 South Australian Research and Development Institute, GPO Box 397, Adelaide, 5001, South Australia, Australia 3 Minnipa Agricultural Centre, Box 31, Minnipa, 5654, South Australia, Australia ¤ vivien.vanstone@adelaide.edu.au Trials at two sites on the Eyre Peninsula of South Aus- tralia were sampled in 1999 and in 2000 to determine ef- fect of phosphorus application on density of Pratylenchus neglectus in trial plots of the susceptible wheat cv. Frame. Initial nematode density ( Pi ) immediately after sowing in 1999 was 5-11 P. neglectus /g dry soil at Miltaburra and 1-3/g at Yandra. In 2000, Pi at Miltaburra was 8-25/g and at Yandra 1-3/g. Final nematode numbers ( Pf ) were de- termined during grain development in spring (September- October). In both years at both sites, Pf decreased as rate of applied phosphorus increased. In 1999, phospho- rus rates of 20-30 kg P/ha reduced P. neglectus density by 30% compared to plots with no added phosphorus. Sim- ilarly, in 2000, nematode levels at Miltaburra were 37% lower and at Yandra 32% lower with 20 kg P/ha compared to control plots. The cropping soils of the Eyre Peninsula are inherently nutrient de cient, and the rainfall low (av- erage annual rainfall 275 mm at Miltaburra and 400 mm at Yandra, with 200 mm and 320 mm, respectively, falling during the growing season). Pratylenchusneglectus in this region is a signi cant impediment to cereal production, and nutrition can play a role in the management of these nematodes. 531 Nematodes on strawberries in Southern Spain: effects on yield and control of Meloidogyne hapla J.M. V EGA 1 ; ¤ , J.I. P ÁEZ 1 , J.M. L ÓPEZ -A RANDA 2 , J.J. M EDINA 3 , L. M IRANDA 3 and F. M ONTES 1 1 Laboratorio de Sanidad Vegetal, CAP-Junta de Andalucía, 41089 Montequinto (Sevilla), Spain 2 CIFA Málaga, CAP-Junta de Andalucía, 29140 Churriana (Málaga), Spain 3 CIFA Las Torres-Tomejil, CAP-Junta de Andalucía, 21800 Moguer (Huelva), Spain ¤ patlbsv.dpse@cap.junta-andalucia.es The province of Huelva, with more than 7500 Has, is the strawberry largest producer area of Spain and one of the largest of Europe. The Laboratorio de Sanidad Vegetal of Seville has been receiving disease strawberry plants from this region during the last fteen years, and the parasitic nematode species detected were Meloidogyne incognita , M. arenaria , M. hapla , Pratylenchuspenetrans , Ditylenchus dipsaci and Aphelenchoides fragariae . Until now a systematic survey on incidence and severity of nematode problem was not made in this area, but during a four years (1998-2001) assays made on two localities (Cartaya and Moguer) on chemicals and non chemicals alternatives to Methyl Bromide, M. hapla was the most important phytopathological problem. Its presence was explained by the use of plantlets from high elevation nurseries located on Castile-Leon (Central Spain). The incidence and severity of root knotted plants and the Vol. 4(2), 2002 309</p>
<p>Integrated management (500-534) number of nematodes present were negatively correlated with some agronomic traits and effect of M. hapla on crop production and fruit quality was studied. Although Solarization, helped with some chemicals or associated to Biofumigation, exerted some nematode population control, only Chloropicrin alone or with DD proved similar ef ciency to Methyl Bromide. 532 Effect of inorganic phosphate fertilisers on the ef cacy of an arbuscular mycorrhiza fungus against a root-knot nematode on pyrethrum J.W. W ACEKE 1 ; ¤ , S.W. W AUDO 1 and R. S IKORA 2 1 Botany Department, Kenyatta University, P.O. Box 43844, Nairobi, Kenya 2 Institute of Plant Diseases, University of Bonn, Nussallee 9, D-53153, Germany ¤ lwanjohi@iconnect.co.ke Effects of triple super phosphate (TSP) and single super phosphate (SSP) fertilisers on ef cacy of a Glomus sp. (isolate KS 14) against Meloidogyne hapla were determined. The fertilisers were applied at the rate of 1 and 2 ¹ g/g soil at the time of fungus inoculation. Two months later, plants were inoculated with the nematodes. Plant growth and nematode disease parameters were determined 2 months after nematode inoculation. The fertilisers at both levels improved plant growth in all treatments. The fungus, in general, improved plant growth on its own or in the presence of nematodes but not in the presence of fertilisers. Both fertilisers at both levels were more effective in improving plant growth than the fungus. The fungus suppressed nematode disease severity unlike the fertilisers. The suppressive effects of the fungus on the nematodes were, in most cases, reduced by the fertilisers. In addition, the fertilisers signi cantly reduced root colonisationof pyrethrum by the fungus. The nematodes, on the other hand, did not have any signi cant effects on root colonisation by the fungus or on its ability to improve pyrethrum growth. The presence of nematodes in fertiliser or fertiliser-fungus-treated plants, however, signi cantly reduced pyrethrum growth. 533 To assess the long-term effects of selected cropping sequences to control Meloidogyne incognita and increase the yield of cotton C.F. W EAVER ¤ , R. R ODRÍGUEZ -K ÁBANA and D.G. R OBERTSON Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama 36849-5409, USA ¤ cweaver@acesag.auburn.edu A 3-year eld study was initiated in central Alabama in a cotton eld infested with Meloidogyneincognita to assess the long-term effects of selected cropping sequences on nematode populations and yields of cotton. In the rst year, six blocks were set up, each containing 24 rows on 4 00 centers. The six blocks were planted with cotton (CT), soybean (SB), pearl millet (PM), corn + velvetbean (CR+VB) and pearl millet + velvetbean (PM+VB). In the 2nd year the rst two blocks were maintained with cotton and soybean monoculture. The remaining four blocks were split with 12 rows of cotton and 12 rows of soybean. In the 3rd year, each block was planted with three cotton cultivars (SG125, SG747, DP458) both non-treated and treated with 2.0 lb a.i./A of aldicarb in two row plots. This setup allowed for the following cropping sequences: (CT-CT-CT), (SB-SB-CT), (PM-SB- CT), (PM-CT-CT), (CR+VB-SB-CT), (CR+VB-CT-CT), (SG+VB-SB-CT), (SG+VB-CT-CT), (PM+VB-SB-CT), and (PM+VB-CT-CT). Treatment with alcicarb across all cropping sequences resulted in a 34% reduction in M. incognita and a 64% increase in yield compared to non- treated cotton monoculture. Most non-treated rotation sequences did not show a reduction in M. incognita compared to non-treated cotton monoculture except for (SB-SB-CT) and (SG+VB-SB-CT) which showed 30 and 41% reductions, respectively. All non-treated rotation sequences averaged a 20% increase in yield compared to non-treated cotton monoculture. The best performing treated rotation sequences were (PM-SB-CT), (PM-CT- CT), (PM+VB-SB-CT) and (PM+VB-CT-CT) resulting in 26, 21, 26 and 21% increases in yield, respectively, over and above what was obtained with treated cotton monoculture. 534 Induced resistance of plants to root-knot nematode S.V. Z INOVIEVA ¤ , N.I. V ASYUKOVA , N.G. G ERASIMOVA , Zh.V. U DALOVA , G.I. C HALENKO and O.L. O ZERETSKOVSKAYA Institute of Parasitology RAS and Bach Institute of Biochemistry RAS, Moscow, Russia, 119071 Moscow, Leninsky prospect, 33 ¤ zinovievas@mail.ru In current investigations the mechanisms of induced plant resistance to parasitic nematode were studied. The activation of protective mechanisms in plants, in- 310 Nematology</p>
<p>Poster sessions hibiting the growth of parasitic nematodes, was stud- ied in the system tomato – Meloidogyne incognita . The biogenic elicitors (arachidonic acid and water- soluble chitosan) stimulated the development of in- vaded tomato plants. Arachidonic acid and chitosan in- duced the accumulation of phytoalexins in the tissues of host plants; decreased the total content of free sterols and changed their composition, producing adverse ef- fects on infesters; activated the chitinase, -glucanase, lipoxigenase, peroxidase, phenylalanine ammonia lyase; and stimulated the generation of reactive oxygen species. The mixture of elicitors with signal molecules (salicylic acid and methyl ether of jasmonic acid) caused more signi cant immunostimulation effect in tomato. The treatment of tomato seeds by elicitors and mixture of elicitors and signal molecules signi cantly suppressed the number of galls and eggs produced and increased duration of nematode development. The data obtained suggest that the natural mechanisms and those induced by biogenic elicitors in tomato to the nematode have the same origin. Vol. 4(2), 2002 311</p>
<p>Animal parasitic nematodes (535-543) 535 Nematodes parasites of some freshwater shes in Zimbabwe Ben N. D UBE ¤ and N.A.G. M OYO University of Zimbabwe, Dept of Biological Sciences, P.O. Box MP 167, Mt. Pleasant, Harare, Zimbabwe ¤ bdube@science.uz.ac.zw The objective of this study was to survey and docu- ment the various nematode parasites that infect some freshwater sh species of economic importance in Zim- babwe. Various species of fresh water sh Tilapia ( Ore- ochromis macrochir , O. mossambicus , O. niloticus ), Trout ( Salvellinus fontanalis) , Green Happy ( Sargochromis co- dringtonii ) and African cat sh ( Clarius gariapinus ) were among some sh specimens collected from the lakes (Chivero, Manyame and Kariba). Fish collections were made during the 12 months of January to December 2001. Freshly collected sh specimens were taken to the labora- tory and all gastrointestinal tracts, liver, vascular system and sh gill contents were removed and examined for the presence of nematode parasites. Excised nematode speci- mens were rst preserved and sent to South Africa marine laboratories for expert taxonomic examination and iden- ti cation. Preliminary results indicate that the most com- mon nematode parasites associated with the gastrointesti- nal tracts and liver from almost all sh species collected are Capillaria spp., Camallanus spp., Contracaecum spp. and Ascaris spp. The Acanthocephalus group of parasites were also encountered and identi ed. It was also noted that in some sh species, nematode parasite counts cor- related with the level of pollution in the respective water bodies. 536 Comparative study of Haemonchus species of different ruminants of Iran A. E SLAMI 1 ; ¤ , S. B OKAIE 2 and S. M ESHGI 1 1 Department of Parasitology 2 Division of Epidemiology, Tehran University, Veterinary Faculty, P.O. Box 14155-6453, Tehran, Iran ¤ aislami@chamran.ut.ac.ir Haemonchus species is reported from sheep, goats, cattle, camel and wild sheep, as well as man in Iran. Identi cation of Haemonchus species in domestic ruminants might be very useful in the study of natural population, especially when two (or three) species are sympatric. In the recent investigation, ten males and ten females of Haemonchus spp. collected from sheep, goat, cattle and camel were examined for total worm length, character of vulval ap in female, length of spicules, and distance from their tip to the tip of the barbs in males. Data were subjected to statistical analysis. Our ndings revealed the presence of three species: Haemonchus longistipes in camel, H. contortus in sheep and H. placei in goats and cattle. Statistical ndings based on one way ANOVA and Tukey post hoc showed that the length of spicules of worms collected from sheep is signi cantly different with those of goats and cattle ( P < 0 : 05 / . Meanwhile, as far as the left and right hook distance from the tip of the spicule is concerned, there was also a signi cant difference between H. placei of goats and cattle with that of sheep ( P < 0 : 05 / . The discriminant function analysis demonstrated further that the three groups of worm could be considered as three different strains. 537 Nematodes of wild cavicorns in the fauna of Uzbekistan A.E. K UCHBAEV , F.D. A KRAMOVA , D.A. A ZIMOV , A. P AZILOV and B. R UZIEV Institute of Zoology Uzbek Academy of Sciences, Tashkent, Republic of Uzbekistan Helminths of the class Nematoda are widespread in the biogeocenoses of Uzbekistan, parasitising all vertebrate species inhabiting aquatic and terrestrial ecosystems. Wild cavicorns in the fauna of Uzbekistan comprise six species, namely, Gazella subgutturosa Guldenstaedt, 1780, Saiga tatarica Linnaeus 1766, Capra falconeri Wagner, 1839, C. ibex Linnaeus, 1758, Ovis ammon karelini Severtzov, 1873 and O. orientalis Gmelin, 1774. The above species inhabit deserts, semi-deserts and are important components of the corresponding biogeocenoses. As a result of a study on parasitic worms of wild cavicorns, 54 nematodes were recorded, of which six are rst records in Uzbekistan. Diversity of helminth fauna in wild cavicorns is as follows: O. ammon , 43; O. orientalis , 41; G. subgutturoza , 35; C. sibirica , 33; C. falconeri , 29; and S. tatarica , 22. Under natural conditions, cavicorn species show, between themselves and domestic animals, close biocenotic links. This promotes circulation of helminths in wild animals. Wild animals play a certain role in epidemiology of a number of helminthoses and take part in distribution of diseases among domestic animals and humans. 312 Nematology</p>
<p>Poster sessions 538 Populatiom ecology of the family Protostrongylidae, Leiper 1926, parasites of animals A.E. K UCHBAEV , F.D. A KRAMOVA and R.R. K ARIMOVA Institute of Zoology, Uzbek Academy of Sciences, Tashkent, Republic of Uzbekistan Nematodes of the family Protostrongylids are adapted to the respiratory system of animals inhabiting mountain ecosystems. They are widely represented in ruminants of the Palaearctic. Fifteen species of Protostrongylids inhabit mountain ecosystems of Uzbekistan, which are the habitats of cavicorns. Dominant species of proto- strongylids of cavicorns are representatives of the genera Protostrongylus , Cyctocaulus and Muellerius . The eco- logical niche for the recorded species of nematodes is the respiratory system, which witnesses high adaptive po- tential of the helminths. Terrestrial molluscs of genera Xeropicta, Pseudonapaeus, Bradybaena , Macrochlamys , Pupilla , Deroceras etc. , participate in life cycles of pro- tostrongylids, in which the 2-3 stage larvae populations develop. Helminths parasitise animals within the system parasite-host. Availability of certain helminth complexes is mainly predetermined by the availability of correspond- ing host groups and microclimatic conditions in the given biogeocenosis which provide the development of all the phases of the parasitic worm ontogeny. 539 Population dynamics of sheep digestive tract strongyloses in Estonian climate conditions E. M ÄGI and A. K AARMA Estonian Agricultural University, Kreutzwaldi 62, Tartu 5104, Estonia parasit@eau.ee The objective of this study was to investigate population dynamics and viability of strongyle larvae on pastures in natural conditions. According to our data, strongyloses of sheep digestive tract are the most widespread parasitic diseases in Estonia. Our observations have shown that pastures contaminated with parasites the previous year are the main sources of invasion. In order to estimate the viability of strongyle larvae on sheep pastures, ve trials with lambs were carried out in different pasture regimes. All lambs were submitted to faecal examinations for numbers of parasite eggs once a week. Our observations have shown that although most strongyle larvae did not survive during the winter period, some of them remained viable up to next grazing period. According to our results, strongyle larvae can be transferred to deep soil layers by earthworms and can remain viable during the whole winter period. To avoid sheep infections, the main prophylactic principle is separate grazing of lambs from ewes because they are the main infection sources in spring. 540 Histology of the anterior intestine of Chabertia ovina G. H OV N ANYAN ¤ and S. M AKARYAN Institute of Zoology, 4 Sevak Street, Yerevan, 375014, Armenia ¤ gurgenh@yahoo.com Histological studies of Chabetia ovina widespread in sheep have never been conducted in Armenia. Chabertia ovina were obtained from large intestines of freshly slaughtered sheep and xed in Barbagallo solution before histological preparation. After azan staining the cuticle of the buccal capsule (BC) and pharyngeal funnel (PF) turn bright red while other tissues in the anterior end turn blue. The pharyngeal gland duct is clearly visible on transverse sections. Haematoxylin-eosin stains all tissues into various shades of red: the lightest are BC and PF cuticles. Clearly outlined are the structure and tissue borders of the pharyngeal musculature and dorsal pharyngeal gland. After ferrous hematoxylin staining the cuticle of the BC and PF turn black, while other tissues in the apical part take various shades of brown. Longitudinal sections clearly show the lamellar structure of the BC cuticle, which is not mentioned in the drawings or textual description of Chabertia ovina . Thus methods used provided new histological results for Strongylidae and complemented each other. 541 Changes in prepatent periods and species composition of Oesophagostomum spp. isolates over time H. T ALVIK 1 ; ¤ , A. J OACHIM 2 and A. K ARIS 3 1 Estonian Agricultural University, Kreutzwaldi 62, Tartu 51014, Estonia 2 Universität Leipzig, An den Tierkliniken 33, Leipzig, Germany 3 University of Tartu, Vanemuise 46, Tartu, Estonia ¤ heta@ph.eau.ee Four eld isolates of Oesophagostomum spp. were collected from Estonian pig farms in 1997 and used for inoculation of eight piglets (2000 L 3 larvae per pig). Four Vol. 4(2), 2002 313</p>
<p>Animal parasitic nematodes (535-543) new pigs were inoculated with the second generation larvae of one isolate kept in the fridge for 3 years. One extra pig was inoculated with 5000 L 3 larvae from the primary eld isolate to follow the egg excretion of the two species by PCR analysis. All four Estonian eld isolates contained Oesophagostomum dentatum and O. quadrispinulatum . Prepatent periods of both nodular worm species varied from 18 to 43 days. Fairly constant egg excretion of both species was demonstrated from day 19 to day 82 post inoculation by PCR analysis. Second generation worms showed shortened prepatent periods and shift towards predomination of O. dentatum (80-85% vs 38% in the rst experiment). It is unclear whether this phenomenon is the consequence of the long storage of larvae in the fridge or some kind of host response. 542 The behaviour of the infective third-stage larvae of the animal-parasitic nematode, Strongyloides ratti H. T OBATA -K UDO 1 ; ¤ , H. K UDO 2 and I. T ADA 1 1 Department of Parasitology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan 2 Department of Anatomy, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan ¤ hi-kudo@par.odn.ne.jp We are analysing the behaviour of Strongyloides ratti infective larvae (L3), a parasite of a rodent, for studying the mechanism of the amphid functions using in vitro agarose tracking assay method. In the present study, we show the behaviours of S. ratti L3, both on a sodium chloride (NaCl) gradient and on a temperature gradient. On a NaCl gradient, two types of chemokinetic behavior were seen: a unidirectionalavoidance movement in unfavourable conditions ( ca 80 mM NaCl) and a random dispersal movement in favourable conditions. Track patterns were straight in the avoidance movement but included multiple changes of direction and loops in the dispersal movement. On a temperature gradient, the direction of thermokinetic behaviour depended on prior experience of environmental temperature. L3 cultured at 25 ± C tended to move towards higher temperatures from releasing points between 22 ± C and 29 ± C. At releasing points of 30 ± C or above, most L3 moved little and showed no directional response. At 20 ± C or below, few or no L3 moved towards the zone of higher temperature. L3 cultured at 20 ± C tended to migrate to a high temperature area regardless of temperature, and those cultured at 30 ± C did not respond to the temperature gradient. 543 Mono- and mixed infection of rats with larvae of Trichinella spiralis Owen, 1835 and T. pseudospiralis Garkavi, 1972 H. Z ANGINYAN ¤ , A. A SATRIAN and M. H ARUTUNYAN Institute of Zoology, NAS RA, Yerevan, P. Sevak 7, Armenia ¤ zang@cornet.am The experiment was undertaken to test male rats of Vistar line. Animals were split up into three groups of ve animals each. Groups I and II were treated as control and infected with larvae of Trichinella spiralis and T. pseudospiralis in a dose of 20 larvae/g body weight of the rat. Group III was treated as trial group and infected with a combination of two Trichinella species in a dose of ten larvae from each species per g body weight. The autopsy was done on day 35 post infection. It was estimated that the formation of larvae in control animals was complete. Trichinella spiralis larvae were encapsulated and those of T. pseudospiralis had their ends twisted or curved. The stage of infection in control animals was 15-20 larvae/g body weight and eight larvae/g body weight in trial animals. These ndings suggest that mixed infection of rats holds back the development of Trichinella and lowers their survival rates. The reason is obviously an interspeci c competition of Trichinella species. 314 Nematology</p>
</body></article></istex:document></istex:metadataXml><mods version="3.6"><titleInfo><title>Symposium</title></titleInfo><titleInfo type="alternative" contentType="CDATA"><title>Symposium</title></titleInfo><typeOfResource>text</typeOfResource><genre type="research-article" displayLabel="research-article"></genre><originInfo><publisher>BRILL</publisher><place><placeTerm type="text">The Netherlands</placeTerm></place><dateIssued encoding="w3cdtf">2002</dateIssued><dateCreated encoding="w3cdtf">2002</dateCreated><copyrightDate encoding="w3cdtf">2002</copyrightDate></originInfo><language><languageTerm type="code" authority="iso639-2b">eng</languageTerm><languageTerm type="code" authority="rfc3066">en</languageTerm></language><physicalDescription><internetMediaType>text/html</internetMediaType></physicalDescription><relatedItem type="host"><titleInfo><title>Nematology</title><subTitle>International Journal of Fundamental and Applied Nematological Research</subTitle></titleInfo><titleInfo type="abbreviated"><title>NEMY</title></titleInfo><genre type="journal">journal</genre><identifier type="ISSN">1388-5545</identifier><identifier type="eISSN">1568-5411</identifier><part><date>2002</date><detail type="volume"><caption>vol.</caption><number>4</number></detail><detail type="issue"><caption>no.</caption><number>2</number></detail><extent unit="pages"><start>123</start><end>314</end></extent></part></relatedItem><identifier type="istex">0BD3A8C6C218D3B6635974A3ACF56C3CBAEC4EBD</identifier><identifier type="DOI">10.1163/15685410260099833</identifier><identifier type="href">15685411_004_02_s005_text.pdf</identifier><accessCondition type="use and reproduction" contentType="copyright">© 2002 Koninklijke Brill NV, Leiden, The Netherlands</accessCondition><recordInfo><recordContentSource>BRILL Journals</recordContentSource><recordOrigin>Koninklijke Brill NV, Leiden, The Netherlands</recordOrigin></recordInfo></mods></metadata><author></author><serie></serie></istex></record>Pour manipuler ce document sous Unix (Dilib)
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