Brief Summary of Minutes of Annual Meeting

NCERA-200 met October 30-31 in conjunction with the Sixth North Central Virus Conference at Iowa State University, Ames. The first day was dedicated to a Virus Symposium entitled Seed Transmitted Viruses in Soybean: Perspectives from Epidemiology, Industry. NCERA 200 Vice President, Les Domier, welcomed the group and presented an overview the meeting program. David Wright, Iowa Soybean Promotion Board and North Central Soybean Research Program, provided perspectives of the soybean industry and commodity boards. He presented an overview of how the NCSRP distributes research funds. He indicated that NCSRP distributes 8% of its funds for virus research and 17% for aphid research. He forecasted that funding for soybean rust will decline and funding will be increased for SCN and SDS. There is support to increase funding for soybean viruses. Sue Tolin, Dept. Plant Pathology, Physiology & Weed Science; Virginia Polytechnic Institute& State University, delivered a presentation entitled Experiences Testing Seed Transmissibility of SMV and BPMV in Southern Soybean Cultivars. She described how Soybean mosaic virus (SMV) continues to be readily seed transmitted and is present in soybean germplasm. Even so, the incidence of seed coat mottling was not related to seed transmission of SMV. The incidence and severity of seed coat mottling caused by Bean pod mottle virus (BPMV) was strain-specific and declined when infection occurred at later growth stages. BPMV had a significant negative effect on seed germination. Transmission of BPMV through seed was not shown conclusively. Gary Munkvold, Department of Plant Pathology, Iowa State University discussed Approaches to Assessing the Risks Associated with Seed-borne Viruses in Soybean. He presented an over view of his role in the Seed Science Center and the Center. He reviewed seed transmission for soybean viruses, focusing on Alfalfa mosaic virus (AMV), BPMV, and SMV. He stressed the importance of understanding seed-borne viruses as they relate to risk of economic loss, phytosanitary regulations, biosecurity, and liability for seed companies. He showed that proper vector management can reduce incidence of mottled seed for both infected and noninfected seeds. Temperature was discussed as a variable important to the presence or absence of SMV seed transmission. The effect of temperature on SMV seed transmission has potential implications on seed testing and epidemiology of yield-limiting viruses. The need for embryo-specific detection methods and the need to determine effects of environment and virus genotype on seed transmission frequency were discussed. Gregory Lamka, Quality Supply Technical Manager; Pioneer Hi-Bred, Johnston, IA, addressed the group on Industry Practices Concerning Seed Transmitted Viruses in Soybean. He noted that the number one complaint from growers is seed appearance. Seed from virus infected plants can have reduced germination, alterations in oil and protein content, and serve as an inoculum source for coming seasons leading to liability issues. Seed producers need to conform to phytosanitary restrictions in the international movement of seed. Because off-season soybean research nurseries are usually located in tropical environment and often use supplemental light, which attracts insects, field plots are frequently sprayed to reduce insect populations. Similarly in the U.S., breeding populations and small seed lots are rigorously observed and monitored for virus infection. Pioneer Hi-Bred has a small effort for virus resistance. More emphasis is placed on vector control by host genetics and insecticides. Recent changes in management practices, i.e., tillage and planting date, are of concern because of potential alterations in vector-virus relationships. Anwar Rizvi, USDA-APHIS-PPQ-PHP; Riverdale, MD, presented a talk entitled Seed Transmitted Viruses in Soybean: A Regulatory View. He described the phytosanitary certification requirements for the movement of seed in and out of the U.S. Small seed lots (50 seeds or 10 grams per taxon and maximum of 50 packets) do not require phytosanitary certification. Exempt are genera not listed Federal Seed Act 7 CFR 361. Larger seed lots are inspected visually for diseases and by x-ray for insects. No biochemical or molecular tests are in place for viruses. Region-specific regulations have been implemented for the importation of seed. For example, peanut seeds can not be imported from India because of the prevalence of Peanut stunt virus in India. New initiatives are under development in consultation with the National Plant Board to revise the list of regulated non-quarantine pests and tolerances. Kitty F. Cardwell, National Program Leader, Plant Pathology, CSREES, USDA; Washington, DC, described the Incorporation of Legume Viruses into the 2007 Pest Information Platform for Extension (PIPE). She demonstrated the National SBR website and described the transition to include the soybean aphid. She explained how the existing model/system could be modified to add viruses and other pathogens. Of virus pathogens of soybean, AMV, BPMV, Cucumber mosaic virus (CMV), Soybean dwarf virus (SbDV) and SMV were considered to be the most important and likely would be added to PIPE. The goal is to establish a baseline of the incidences of the viruses in soybean and Phaseolus beans and other legumes. Inputs, outputs and potential users were discussed. Public sector researchers are expected to be major contributors, but industry representatives stressed importance of including the private sector. Sample management and movement protocols were discussed and are in developmental phases for each target pathogen. NCERA 200 Business Meeting Loren Giesler was elected secretary for 2007. The location, Ames, IA, and dates, October 29  30, 2007, were set for the 2007 meeting. 2007 Symposium: The three officers will constitute a Symposium Committee and elicit potential topics. See attachment for full Annual Report.

During 2006, the NCERA200 project facilitated the collaboration of scientists in the North Central region in the analysis of soybean-virus-vector bilateral and trilateral interactions. For example, the structure established by NCERA200 allowed M. R. Hajimorad (University of Tennessee) to quickly assemble a large set of AMV isolates that included isolates from Illinois, Indiana, Ohio, Wisconsin, Tennessee and Virginia. The AMV isolates will be used to test and develop diagnostic reagents that will be used by other scientist in the region. In addition, the structure afforded by NCERA200 facilitated writing of a grant that was funded by the North Central Soybean Research Program (described below). As part of the outreach of the project, a symposium on seed transmitted soybean viruses was held in Ames, IA in conjunction with the NCERA200 meeting. The symposium was attended by researchers, members of commodity boards, representatives of soybean seed companies and soybean producers. Plans for coming year: The date and location of the meeting for 2007 have been set. A committee has been formed to select a topic for a soybean virus-related symposium. Efforts will be made to publicize the symposium among a wider range of potential attendees. The NCERA200 committee will continue to coordinate research on virus and their vectors in the management in the North Central region. Where appropriate, the committee will work to develop consistent information sets for distribution through print and electronic media.

Hajimorad, M.R., Eggenberger, A.L., and Hill, J.H. 2006. Strain-specific P3 of Soybean mosaic virus elicits Rsv1-mediated extreme resistance, but absence of P3 elicitor function alone is insufficient for virulence on Rsv1-genotype soybean. Virology 345:156-166. Hill, C.B., G.L. Hartman, R. Esgar, and H.A. Hobbs. 2006. Field evaluation of green stem disorder in soybean cultivars. Crop Science 46:879-885. Hill, C.B., Y. Li, and G.L. Hartman. 2006. A single dominant gene for resistance to the soybean aphid in the soybean cultivar Dowling. Crop Science 46:1601-1605. Hill, C.B., Y. Li, and G.L. Hartman. 2006. Soybean aphid resistance in soybean Jackson is controlled by a single dominant gene. Crop Science 46:1606-1608. Hill, J.H., Koval, N.C., Gaska, J.M., and Grau, C.R. 2006. Identification of field tolerance to Bean pod mottle and Soybean mosaic viruses in soybean. Crop Science. in press. Hobbs, H.A., Hill, C.B., Grau, C.R., Koval, N.C., Wang, Y., Pedersen, W.L., Domier, L.L., and Hartman, G.L. 2006. Green stem disorder of soybean. Plant Disease 90:513-518 Koval, N., Grau, C., and Cullen, E. 2006. Understanding virus potential in commercial soybean fields. Wisconsin Fertilizer, Aglime, and Pest Management Conference Vol 45:115-121. Mueller, E.E., and Grau, C.R. 2006. Seasonal progression, symptom development, and yield effects of Alfalfa mosaic virus epidemics on soybean in Wisconsin. Plant Disease In press Wang, L., Eggenberger, A., Hill, J., and Bogdanove, A.J. 2006. Pseudomonas syringae effector avrB confers soybean cultivar-specific avirulence on Soybean mosaic virus adapted for transgene expression but effector avrPto does not. Molecular Plant-Microbe Interactions 19(3):304-312. Wang, R.Y., Kritzman, A., Hershman, D.E. and Ghabrial, S.A. 2006, Aphis glycines as a vector of persistently and nonpersistently transmitted viruses and potential risks for soybean and other crops. Plant Disease 90:920-926. Zhang, C.Q., and Ghabrial, S.A. 2006. Development of Bean pod mottle virus-based vectors for stable protein expression and sequence-specific virus-induced gene silencing in soybean. Virology 344:401-411.