Alvarez, Juan Manuel(jalvarez@uidaho.edu)-University of Idaho;
Batchelor, Dallas(dbatchelor2b@charter.net)-Lamb Weston;
Bateman, Melinda(melindab@uidaho.edu)-University of Idaho;
Berger, Phil(Philip.h.berger@aphis.usda.gov)-USDA/APHIS;
Bohach, Greg(gbohach@uidaho.edu)-University of Idaho;
Brown, Chuck(cbrown@pars.ars.usda.gov)-USDA/ARS;
Crosslin, Jim(jcrosslin@pars.ars.usda.gov)-USDA/ARS;
Davis, Jeff, (davis271@umn.edu)-University of Minnesota;
Gray, Stewart (smg3@cornell.edu)-USDA-ARS;
Guzman, Pablo (pguzman@ucdavis.edu)-California Department of Agriculture-Davis;
Hall, Darren (dhall@uidaho.edu)-USDA-ARS;
Hamm, Phil (phillip.b.hamm@oregonstate.edu)-Oregon State University;
Hane, Dan (dan.hane@oregonstate.edu)-Oregon State University;
Franc, Gary (francg@uwyo.edu)-University of Wyoming;
French, Allan (Allan.French@simplot.com)-Simplot;
Laug, Sherry(slaug@idahocrop.com)-Idaho Crop Improvement Association;
Lorenzen, Jim (jiml@uidaho.edu)-University of Idaho;
Malik, Ved (Vedpal.s.malik@usda.gov)-USDA-APHIS;
Marquardt, Steve (smarquardt@state-seed.ndsu.nodak.edu)-North Dakota State Seed Department;
Munyaneza, Joe (munyaneza@yarl.ars.usda.gov)-USDA/ARS;
Navarre, Roy (rnavarre@pars.ars.usda.gov)-USDA/ARS;
Nolte, Phil (pnolte@uidaho.edu)-University of Idaho;
Pappu, Hanu (hrp@wsu.edu)-Washington State University;
Piche, Lisa (Lisa.Piche@ndsu.nodak.edu)-North Dakota State University;
Sather, Kent(ksather@lamar.colostate.edu)-Colorado State University;
Srinivasan, Babu (srin8536@uidaho.edu)-University of Idaho;
Thompson, Colleen (cthompson@idahocrop.com)-Idaho Crop Improvement Association;
Whitworth, Jonathan(jwhit@uidaho.edu)-USDA-ARS
The full minutes are included in the attached file. The following is a brief summary.
Discussions surrounding PVY (effects on seed industry, difficulties in dealing with newer strains, effects on seed programs and international movement of potatoes, management schemes, insect involvement, variety response differentials, detection and strain differentiation, genetic resistance, reviews of current research) dominated this meeting session, indicating the importance and difficulties in dealing with this virus. The following motion was formulated from those discussions:
A motion was made: C. Brown proposed that the WERA-89 should form a committee that would formulate a statement on PVY management at a national level by July 1, 2005. S. Gray seconded the motion and it was unanimously approved. C. Brown will chair the committee and Gray, Whitworth, Hamm, and Thompson will be also part of the committee.
Additionally, it was reported that evidence indicates an increase in the incidence of Tobacco Rattle Virus and Alfalfa Mosaic Virus as well as in PVY strains.
Discussions on PLRV covered genetic resistance, inoculum sources, and alternate hosts.
Molecular and biochemical resistance to Tobacco Mosaic Virus (TMV) were presented. Finding a local lesion host for TMV would be useful in screening for this virus. Induced resistance to pests by potato was also discussed.
Identification of the casual agent of Purple Top (Columbia Basin Potato Purple Top Phytoplasma) in the Columbia basin provided evidence that this was not in the aster yellows phytoplasma group. This beet leafhopper transmitted viralescence agent (BLTVA) can cause 15% yield losses in potato.
Jim Crosslin was unanimously elected to the position of secretary. Juan Alvarez will move into the position of vice-chair, and Hanu Pappu acquires the chair position for the coming year.
WERA-089 input provided the expertise required to establish a necrotic virus management plan between the U.S. and Canada which was signed and funding for a national survey portion was secured. Criteria for describing the PVY complex was developed which was included in this virus management plan. Some variety differentials were defined. Also, a tuber survey was completed indicating an increase in PVY in general.
Methods for identifying PVY strains with ELISA and PCR have been refined.
Facilitated the proper testing for seed certification agencies to accurately assess the PVY strain diversity in the potato seed industry.
Assessing new testing technology options so that seed certification agencies can properly evaluate technology upgrades.
Establishing resolutions to guide policymakers on identifying and establishing priority research areas to solve virus problems in potato.
Facilitated the assessment of the potato mop top threat.
Facilitating a multistate cooperative team effort to establish the beet leafhopper as the sole vector of the phytoplasma that causes purple top diseases in the Columbia Basin.
Characterization and establishment of the etiology of purple top disease in the Columbia Basin and discovery of the insect vector and its phenology.
Up-dated participants on new and on-going research efforts directed at virus (& phytoplasma) problems in potatoes.
- Potato virus Y and Potato mop top virus threatened the potato seed and production industries in the U.S. and Canada and caused international trade barriers. Much of the new knowledge about this group of viral diseases was developed through investigations, conducted by this WERA. Our work helped develop an updated and a more effective virus management plan. The trade barriers between the U.S. and Canada were reduced and managed effectively.
- A severe outbreak of a previously unrecognized potato disease caused extensive crop losses in the Columbia basin from 2002-04. An interdisciplinary team was established and undertook extensive research and extension efforts and led to the identification of the causative agent, a new phytoplasma, and its insect vectors. Identification of the agent and determination of the phenology allowed the group to establish appropriate management practices resulting in complete control.
Alvarez, J.M. 2004. Potato insect pests. In J.L. Capinera (ed.), Encyclopedia of Entomology. Klower Academic Press, 1803-1816.
Alvarez, J.M. 2004. Nightshade plants are an aphid magnet and also harbor potato viruses. Potato Grower, 33: 44-46.
Alvarez, J.M. and R. Srinivasan. 2005. Evaluation of hairy nightshade as an inoculum source for the aphid-mediated transmission of potato leafroll virus. J. Economic Entomol. In press.
Alvarez, J.M. and R. Srinivasan. 2005. Evaluation of hairy nightshade as an inoculum source for the aphid-mediated transmission of potato leafroll virus. J. Economic Entomol. In press.
Boydston, R.A., H. Mojtahedi, J.M. Crosslin, P.E. Thomas, T. Anderson, E. Riga. 2004. Evidence for the influence of weeds on corky ringspot persistence in alfalfa and Scotch spearmint rotations. Am. J. Pot. Res. 81:215-225.
Crosslin, J.M., J.E. Munyaneza, A. Jensen, and P.B. Hamm. 2005. Association of beet leafhopper (Hemiptera: Cicadellidae) with a clover proliferation group phytoplasma in Columbia Basin of Washington and Oregon. J. Economic Entomol. 98:279-283.
Crosslin, J.M., P.B. Hamm, P.J. Shiel, D.C. Hane, C.R. Brown, and P.H. Berger. 2005. Serological and molecular detection of tobacco veinal necrosis isolates of Potato Virus Y (PVYN) from potatoes grown in the western United States. Am. J. Pot. Res. (in press; accepted Dec. 7, 2004).
Nolte, P., JL Whitworth, MK Thornton and CS McItosh. 2004. Effect of Seedborne Potato virus Y on Performance of Russet Burbank, Russet Norkotah and Shepody Potato. Plant Disease 88:248-252.
Novy, R.G., Alvarez, J.M., Corsini, D.L., Nasruddin, A., Radcliffe, E.B., and Ragsdale, D.W. 2004. Resistance to PVY, PLRV, PVX, green peach aphid, colorado potato beetle, and wireworm in the progeny of a tri-species somatic hybrid. Am. J. Pot. Res. 81 (1): 77-78.
Piche, L.M., R. P. Singh, X. Nie, and N. C. Gudmestad. 2004. Diversity Among Potato virus Y Isolates Obtained from Potatoes Grown in the United States. Phytopathology 94:1368-1375.