Brief Summary of Minutes of Annual Meeting

Chair John Hill called the meeting to order, and introductions of all members and quests were made. The first order of business was to elect new officers. Marie Langham was nominated and elected by majority vote to serve as Secretary for the committee. Les Lane was nominated and unanimously elected to serve as Vice Chair and to become the next chair. A suggestion was made to have two e-mail listings: one with official members only and a second one with members and other interested parties.

Chair Hill (Iowa) started the meeting by discussing the two principal soybean viruses, bean pod mottle virus (BPMV) and soybean mosaic virus (SMV). BPMV, an approach for a short-term control measure, may be found by looking for reduced antigen load in the seed as opposed to looking at the foliar antigen load. Craig Grau (Wisconsin) and Chair Hill have been studying an approach to determine the antigen load in the seed. Companies favor selection of high yielding and low mottling soybean lines. However, this could favor the selection of a Typhoid Mary. Development of a virus index number might prevent this. For SMV, the RSV1 resistance gene is affective; however, this gene has a two tiered mode of action of with extreme resistance and hypersensitive reaction. Selection pressure on virus isolates has produced isolates with modified responses to this resistance. Les Domier (Illinois) inquired about experiments that were underway on BPMV transgenic resistance. Some research that was effective against BPMV (#2) was cited as being done at Pioneer and Monsanto. However, the history of companies dropping projects was cited as a problem to the control of these viruses. Chair Hill stated that the companies would have to play a role in the control of these viruses due to the problem of seed infection or contamination.

Les Domier began his report by reminding everyone of Glen Hartmans presentation the previous day and their collaboration with the Illinois Natural History Survey. Through this program, they surveyed for bean leaf beetles and soybean aphids and collected plant samples for testing. Samples taken from every county with high BPMV incidence had not demonstrated a connection between Green stem and BPMV. Crosses are being done with low and high green stem incidence lines. Cage studies to evaluate the soybean aphid resistance of soybean cultivars are underway. Surveys were also done for Luetoviruses in soybean and legumes, but soybean dwarf virus (SbDV) has not been found. Discussion of the vectors for SbDV in the US and Japan followed. Les continued with a summary of their work with tobacco ringspot virus (TRSV) including seed to seed passage to promote seed transmissibility. Les Lane (Nebraska) inquired about old varieties with green stem. Was the rate the same or is this the result of a new susceptibility, cultural practices, or chemicals? Would older varieties that seemed to have lower green stem have the same level of green stem if they were planted today under todays practices? Discussion followed on the impact of environmental stresses on virus and on the publication of data from environmental stresses research in on-line journals where the publication of climate-based research could be received favorably.

Les Lane discussed the research in Nebraska that Loren Geisler and he had in progress. Lorens research included date of planting studies, field-testing of common soybean breeding lines and the top ten commercial varieties, and levels of insecticide. Les had been focusing on TRSV that had been found in Nebraska. Its symptomalogy varied from the classical bud blight. It will skip local lesions and become systemic. He intends to inoculate this strain to different soybean varieties. Chair Hill reminded everyone of the Plant Health Initiative website that would have space for the posting of evaluation research and the ability to indicate how it was done.

Berlin Nelson (North Dakota) contributed that during the past two years, they had surveyed 150 fields for BPMV, SMV, alfalfa mosaic virus (AMV), and tobacco streak virus (TSV). There were no positives found.

Roberto Micheletti (Canada) reported that this was the second year of a continuing survey for plant viruses in soybean. SMV, BPMV, TRSV, and AMV were found. SMV, BPMV, and TRSV had been found previously in soybean in Canada, but this is the first identification of AMV. TRSV was found in sixteen samples, SMV was diagnosed in thirteen samples, and twenty plants were positive for BPMV. Seed testing for BPMV and SMV from various soybean lines found only one positive test for SMV. Ninety-three bean leaf beetles tested for BPMV were found not to be positive. Discussion on the location of BPMV, SMV, and TRSV in the seed suggested varied locations for the different viruses and in different plants.

Jim Schoelz (Missouri) discussed the work done with Laura Sweets. All soybean samples positive for virus this year were BPMV with the exception of one that was positive for TRSV. Heavy beetle populations were present. One sample of AMV-infected Medicago was found. Sue Tolin (Virginia) commented that inoculating clovers were different and sometimes difficult. Marie Langham (South Dakota) commented about spreader rows.

Sue Tolin (Virginia) reported on genes that were introduced into Essex, resistance breaking in Hutchinson, field inoculations of SMV and BPMV, and dual inoculations.

Marie Langham (South Dakota) summarized studies on trials of inoculation techniques, insecticide trials for control of BPMV through control of the bean leaf beetle, and evaluations of soybean experimental lines and cultivars.

Steve Slack (Ohio) joined the group to discuss the websites, requirements of the committee, mailing lists, Appendix E, and members. He also addressed his role as administrator of the committee. His e-mail address is oardc@osu.edu.

Suggestions were made about soliciting the contributions of others, and the meeting was closed.

Viral diseases have rapidly developed into major threats to soybean production in the North Central Region. The predominant viruses found in the North Central Region are: Bean pod mottle virus (BPMV), Soybean mosaic virus (SMV), Tobacco ringspot virus (TRSV), Tobacco streak virus (TSV) and Alfalfa mosaic virus (AMV). Variation in the virus incidence and the predominant virus changes across the region. For example, BPMV occurs at higher incidence in Nebraska and South Dakota than in Wisconsin. Virus incidence across the region also directly varies with the vector population required for transmission of the virus. For example, higher populations of bean leaf beetle in Wisconsin during this period led to a higher than average incidence of BPMV. Research continues on elucidating field epidemiology, determining seed transmission, increasing basic knowledge of the viruses, and developing methods of increasing host plant resistance through evaluation or transformation.
State reports are available as additional attachmenets in NIMSS.

Giesler, L. J., Ghabrial, S. A., Hunt, T. E., and Hill, J. H. 2002. Bean pod mottle virus. A threat to U.S. soybean production. Plant Disease 86:1280-1289.

Gu. H., Clark, A. J., de Sa, P. B., Pfeiffer, T. W., and Ghabrial, S. A. (2002). Genetic diversity among isolates of Bean pod mottle virus. Phytopathology 92:446-452.

Koning, G., TeKrony, D. M., Ghabrial, S. A., and Pfeiffer, T. W. (2002). Soybean mosaic virus (SMV) and the SMV resistance gene (Rsv1): influence on Phomopsis Spp. seed infection in an aphid-free environment. Crop Sci. 42:178-185.

Giesler, L. J., Ghabrial, S. A., Hunt, T. E., and Hill, J. H. (2002). Bean pod mottle virus: A threat to U.S. soybean production. Plant Disease 86:in press. Feature Article

Wang, R. Y., and Ghabrial, S. A. (2002). Effect of aphid behavior on efficiency of transmission of Soybean mosaic virus by the soybean- colonizing aphid, Aphis glycines. Plant Disease 86: 1260-1264.