Brief Summary of Minutes of Annual Meeting

2000: " Establish a low soil volume bioassay to evaluate nematode antagonistic crops. A low volume soil bioassay developed in PA was used to evaluate toxicity of green or freeze-dried plant extracts on plant parasitic nematodes in CT, MA, NY, and WV. " Conduct a workshop for all group members to present protocols for Pasteuria penetrans recognition, research and surveys. A workshop conducted in FL to taught members to recognize Pasteuria spp. on different species of nematodes with the goal that all members follow prescribed methods in working with Pasteuria. " Initiate collaborative rotation and cover crop system research in field plots and microplots in multiple states. Collaborative multi-state interdisciplinary competitive projects were awarded to NE171 scientists. Maryland participated in a grower-generated project on the use of cover crops, soil amendment, and tillage to manage root knot. A multidisciplinary project was funded to Michigan, Wisconsin, New Jersey and New York. Grower trials were conducted on rotation and cover crops, resistance, biological control, and natural products. The host status of nematode-suppressive rotation crops or green manures was investigated on nematodes in CT and PA. " Identify and evaluate nematode resistant or tolerant varieties for inclusion in an integrated management program. A number of crops were evaluated for resistance or tolerance to nematodes, including the USDA Capsicum germplasm collection for reaction to Meloidogyne (USDA-SC); strawberry cvs were evaluated against black root rot pathogens in CT; Onion germplasm (>50 accessions of Allium spp.) were evaluated against M. hapla (NY); carrot cvs were evaluated against M. hapla (NY); and selected soybean cvs were found to be hosts to P. penetrans. Bell pepper (Capsicum annuum) cvs near isogenic for the N gene for resistance to root knot were evaluated (USDA-ARS-SC); and C. colocynthis (21) and C. lanatus var. citroides (88) accessions, and C. lanatus var. lanatus (155) accessions from the U.S. Citrullus collection were evaluated against M. arenaria race I. Results demonstrated resistance, tolerance, or genetic variability within the cultivars or PI's tested. 2001: " Survey northern states for the presence of Pasteuria penetrans using protocols identified in 2000. Pasteuria penetrans or Pasteuria-like organisms were discovered attached to Heterodera iri from turf (CT). Pasteuria were detected in 77% of Long-Term Ecological Research plots in MI. Pasteuria spp. were associated with plant nematodes, fungivores and bacterivores. A New York survey detected Pasteuria from Tylenchorhynchus spp., Tylenchus spp., and Meloidogyne sp. Free-living Cephalobus sp. and Eucephalobus sp. were also found with endospores. Samples from putting greens in MA all had Pasteuria-infected Tylenchorhynchus. Other nematodes with Pasteuria included Helicotylenchus, Hoplolaimus and Meloidogyne. Conditions were defined for detection of Pasteuria spp endospores using a monoclonal antibody against an epitope of the parasporal fibers that cover mature endospores. An amplification ELISA using biotinylated secondary antibody quantified a minimum of 300 endospores per g soil, and may also quantify endospores in roots. FL developed DNA probes for detection of vegetative stages of Pasteuria using published genome sequences for Bacillus subtilis and B. halodurans, free-living endospore-forming bacteria, as a basis for designing primers for PCR amplification of orthologous genes from Pasteuria. Degenerate primers and anealing conditions were used to amplify PCR products using DNA templates obtained from P. penetrans P20 endospores. Using Real-Time PCR, M. arenaria infection level by vegetative cells of P. penetrans was determined. The assay selectivity was confirmed as primers did not detect DNA in uninfected M. arenaria. This work identified gene sequences unique to P. penetrans. Using these primers, the level of infection by P. penetrans may be determined before sporulation. This will be complementary to the immunoassay recognizing an epitope present on mature spores. " Evaluate crops and greenhouse or growth chamber systems for the production of large numbers of Pasteuria penetrans endospores. Rutgers tomato and PA136 Bell pepper were selected as hosts for culture of Meloidogyne incognita based on root vigor and cultural manageability, and grown in a greenhouse soil moisture control system (Sardanelli and Kenworthy, 1997). Root-knot density and Nemacur treatment were evaluated in MA for impact on the incidence of infection by Pasteuria. There was an inverse relationship between nematode numbers and Pasteuria. Nematicide did not affect the incidence of Pasteuria infection. 2002: " Initiate research to determine the mechanism of nematode antagonism in rotation and cover crops. A bioassay developed in PA using freeze-dried plant material was used to detect the presence of potential nematicidal compounds. Xiphinema americanum were exposed to freeze-dried leaf and root tissue. Nematodes were not killed in sterile sand or water, and mortality increased with amounts of tissue. The LC50 ranged from 0.6 mg (Nasturtium) to 13.2 mg (Sunn hemp) per cc of sand. Nasturtium leaves showed potent nematicidal activity with an LC50 of 0.6 mg. (CT) In cooperation with PA, the host status of several rotation crops was evaluated against Pratylenchus penetrans and Meloidogyne hapla. Shoot incorporation indicated that plant breakdown products may be nematicidal. " Compare isolates of Pasteuria penetrans for host preference and biocontrol potential. The long-term persistence and suppression of Pasteuria penetrans against Meloidogyne arenaria were investigated over 9 years of crop cultivation and weed fallow in FL. FL developed a monoclonal to quantify Pasteuria endospores in soil. We also developed assays for DNA sequences unique to different species of Pasteuria to quantify host specificities. The incidence of the bacterium was related to the density of the peanut root knot nematode, but not M. javanica. (MA) The relationship of Pasteuria penetrans to Meloidogyne graminis and Tylenchorhynchus spp was investigated on golf greens. A correlation between percent Pasteuria- encumbered juveniles and the density of M. graminis and Tylenchorhynchus was found. " Evaluate the impact of rotation and cover crops and soil amendments on nematodes. Experiments were conducted combining an alkaline-stabilized biosolid (ASB) amendment with Streptomyces sp. for M. incognita control. Only ASB at the highest rate (3% wt/g soil) reduced M. incognita. No suppression was achieved by applying Streptomyces sp. to soil (USDA ARS Beltsville). (PA) Compost was evaluated for ability to suppress dagger nematodes in an apple orchard. Plots treated with five inches of mushroom compost consistently had the lowest nematodes, suggesting that mushroom compost is suppressive to dagger nematodes. (CT) Rotation and green manure crops resulted in lower lesion nematode densities. Incorporation of crop shoots further reduced nematodes. Rudbeckia and marigold controlled nematodes without incorporation. A single season of marigold controlled P. penetrans and increased tuber yields in potato plots. The effects of the organic butyric and propionic acids against Meloidogyne hapla on tomatoes and Pratylenchus penetrans on strawberries in RI indicated that Vydate and butyric acid treatments were similar. 2003: " Evaluate the winter survival of Pasteuria penetrans in northern states. (MA) Pasteuria penetrans on Meloidogyne graminis and Tylenchorhynchus has overwintered on turf in golf greens in Massachusetts. Pasteuria spores were present on the cuticles of M. hapla juveniles after exposure to winter conditions in CT. Pasteuria endospores appear to readily survive the winter in CT, MA, NY and MI. " Determine the sequence of events required for formation of endospore-associated proteins and adhesion to nematodes. (FL) Pasteuria penetrans cannot be grown in vitro or enumerated by bacteriological methods; therefore, an immunoassay was developed to quantify spores. A monoclonal antibody (MAb) produced against whole spores was shown to bind a putative glycan epitope present on the spore envelope. Following SDS-PAGE of cuticle extracts and immunoblotting with spore extracts and the MAb as probes, the glycopeptides were shown to bind to discrete polypeptides derived from the nematode cuticle. The MAb detects an epitope of adhesins that are involved in the attachment of Pasteuria endospores to the nematode cuticle. An indirect amplification ELISA was developed to quantify spore adhesins. Regression of spore concentration versus signal produced line fits of 0.98 and indicated a detection limit of 3000 spores/g soil. Western blot profiles of soil-extracted antigen were the same as those provided by extracts of purified endospores, confirming that the ELISA detects Pasteuria adhesins in soil. The MAb did not detect antigens on cells or endospores derived from other endospore-forming bacteria. This establishes the MAb as a definitive probe to detect adhesins as virulence determinants on Pasteuria endospores in soil. " Integrate plant resistance with rotation crops to predict nematode population decline under integrated management systems. Potato cvs were rated for root-galling severity in NY. All potatoes tested had galls on fine fibrous, but not coarse roots. Large numbers of eggs were recovered from all cvs, which were hosts of M. hapla. Carrot cvs were evaluated against M. hapla. All cultivars tested were hosts of M. hapla. Black root rot is a strawberry disease caused by Rhizoctonia fragariae and Pratylenchus penetrans. Cultivars that performed well in yield and vigor after 3 years in infested soils in CT were Latestar, Primetime, Annapolis, Lester, Idea, Winona and Earliglow. Results from USDA-ARS SC demonstrated genetic variability within the U.S. PI Citrullus germplasm collection for resistance to M. arenaria race 1. The C. lanatus var. citroides accessions are sources of resistance to M. arenaria race 1 in watermelon. Peppers with the N gene for resistance to southern root-knot nematode have been useful in management. A pepper PI with moderate resistance to M. hapla has been identified for use in the Northeast. 2004: " Evaluate rotation and cover crop effects on nematode community structure in soil. A workshop on identification of free-living nematodes at the 2002 Technical Committee Meeting was held to assist researchers evaluating the impact of nematode management on nematode community structure. Dr. Bird has prepared chapters on 'nematode biology and management' & 'nematodes and soil quality' in two interdisciplinary MSUE Bulletins. The effects of seasonal changes in nematode community structure were determined in long-term ecological plots in MI. " Determine the morphological and phylogenetic relations among Pasteuria penetrans isolates. Phylogenetic analysis of the sigE gene from gram-positive endospore-forming bacteria finds Pasteuria penetrans most closely related to Paenbacillus polymyxa. SigE is a sporulation gene with sequence diversity for species and biotype differentiation of Pasteuria. The development of a DNA library from Pasteuria represents a special case. The GenomiPhi process was evaluated from Bacillus subtilus cells and indicates that a complete Pasteuria library may be prepared from as little as 1000 bacterial genomes from single nematodes. " Develop an economic analysis of rotation and soil amendment tactics for nematode control. The analysis of nematode community structure in long-term ecological sites in MI has led to 5 proposed categories of soil health and quality based on disturbance, soil nutrient/amendment inputs, and system degradation. Within a category, rotation with nematode-resistant soybeans has shown an economic advantage of 9 to 26%.

Bird, G. W. 2003. Role of integrated pest management (in) Integrated pest management in the global arena, pp. 73-85 (in) Maredia, K. S., D. Dakouo and D. Mota-Sanchez (eds). CABI Publishing, Cambridge. 512.pp. Brito, J. A., J. F. Preston, D. W. Dickson, R. M. Giblin-Davis, D. S. Williams, H. C. Aldrich, and J. D. Rice. 2003. Temporal production and immunolocalization of an epitope during Pasteuria penetrans sporogenesis. J. Nematol. 35:278-288. Fery, R. L., J. A. Thies and A. G. Gillaspie. 2004. 'KnuckleHull-VNR', a crowder-type southernpea resistant to blackeye cowpea mosaic virus and root-knot nematode. HortScience 39:183-184. Halbrendt, J. M., and J. A. LaMondia. 2004. Crop rotation and other cultural practices. Pp.273-294 in, Nematology, Advances and Perspectives. Z. X. Chen, S. Y. Chen, and D. W. Dickson, eds. Kokalis-Burelle, N., and D. W. Dickson. 2004. Evaluation of Plantpro 45 and Plantpro 20EC as alternatives to methyl bromide soil fumigation for tomato production in Florida. Nematropica 33:171-178. Kratochvil, R. J., S. Sardanelli, K. E. Everts, and L. E. Gallagher. 2004. Evaluation of Crop Rotation and other Control Practices for Management of Root-knot and Lesion Nematodes. Agron. J. 2004; 96:1419-1428. LaMondia, J. A. 2004. Field performance of twenty-one strawberry cultivars in a black root rot-infested site. Journal of the American Pomological Society 58(4):226-232. Levi, A., C. E. Thomas, J. A. Thies, A. M. Simmons, Y. Xu, X. Zhang, O. U. K. Reddy, A. R. Davis, and T. Wehner. 2004. Developing a genetic linkage map for watermelon: polymorphism, segregation, and distribution of markers. Progress in Cucurbit Genetics and Breeding Research. A. Lebeda and H. S. Paris (Eds.) p. 515-523. Mervosh, T. L., and J. A. LaMondia. 2004. Strawberry black root rot and berry yield are not affected by use of terbacil herbicide. HortScience 39(6):1339-1342. Meyer, S.L.F., R.N. Huettel, X.-Z. Liu, R.A. Humber, J. Juba and J. Nitao. 2004. Activity of fungal culture filtrates against soybean cyst nematode and root-knot nematode egg hatch and juvenile motility. Nematology 6: 23-32. Padgham, J. L., J. M. Duxbury, A. M. Mazid, G. S. Abawi, and M. Hossain. 2004. Yield loss caused by Meloidogyne graminicola on lowland rainfed rice in Bangladesh. J. of Nematology 36: 42-48. Padgham, J. L., G. S. Abawi, and J. M. Duxbury. 2003. Survival and infectivity of Meloidogyne graminicola in flooded and non-flooded soils. Nematol. Medit. 31:225-230. Schmidt, L. M., J. F. Preston, G. Nong, D. W. Dickson, and H. C. Aldrich. 2004. Detection of Pasteuria penetrans infection in Meloidogyne aerenaria race 1 in planta by polymerase chain reaction. FEMS Microbiol. Ecol. 48:457-464. Smith. J. and G. W. Bird. 2003. Impact of physical and chemical and biological disturbances on nematode community structure. Journal of Nematology 35:364-365. Thies, J. A., R. L. Fery, J. D. Mueller, G. Miller, and J. Varne. 2003. Response of bell pepper cultivars near-isogenic for the N gene to Meloidogyne incognita in field trials. HortScience 38:1394-1396. Thies, J. A., R. F. Davis, J. D. Mueller, R. L. Fery, D. B. Langston, and G. Miller. 2004. Double cropping cucumbers and squash after resistant bell pepper for root-knot nematode management. Plant Disease 88:589-593. Thies, J. A. and A. Levi. 2003. Resistance of watermelon germplasm to the peanut root-knot nematode (Meloidogyne arenaria race 1). HortScience 38:1417-1421. Walia, R. K., T. E. Hewlett, and D. W. Dickson. 2004. Microwave treatment of Pasteuria penetrans parasite preparation for selective elimination of undesired microorganism. Nematologia Mediterranea 32:15-17.