Assessing Virus Resistance in New York Grown Potato Varieties and Breeding Lines: Disease resistance as an integral part of pest management 2003
Project Leader: Keith Perry, Department of Plant Pathology
Cooperators: Stewart Gray, USDA-ARS & Department of Plant Pathology
Walter De Jong, Department of Plant Breeding
Type of Grant: Pest Resistant Crops
Project Locations: New York, Maine, and nationally
In 2002, two viruses that are part of an emerging potato disease complex (tuber necrosis) were first described in the US. Viruses can be difficult to score visually, compromising seed certification programs. The focus of this proposal is: i) the collection of Potato Virus Y (PVY) field isolates representative of those compromising potato production, and ii) testing commercial varieties and breeding lines to assess their resistance phenotypes. Plants from commercial production areas were analyzed to determine which of the common viruses are present, namely, Potato Virus A (PVA), Potato Virus M (PVM), Potato Virus S (PVS), Potato Virus X (PVX), PVY or Potato Leafroll Virus (PLRV). Of the 500 plants sampled, 386 contained PVY, most commonly with one or more other viruses. Twenty one of the commercial varieties can be inferred to be PVY susceptible. Five of the samples contained "necrotic isolates" of PVY that induced a veinal necrosis when inoculated onto tobacco. Two of these necrotic PVY isolates were not recognized by the diagnostic monoclonal antibody used in Foundation Seed programs, and three of the isolates were recognized by the diagnostic monoclonal antibody, but did not give rise to a veinal necrosis. These results emphasize shortcomings in the accepted methods of disease management. We now have in hand representative field isolates of PVY. This will allow us to assess the resistance phenotype of potato breeding lines and commercial varieties.