1a.Objectives (from AD-416):
Potato virus Y (PVY) is a serious disease problem in the seed potato crop. The seed potato industry set goals to reduce PVY incidence and to eliminate where possible the new tuber necrotic isolates. Our objectives are to assist seed certification agencies in methods for detecting and eliminating PVY from seed stocks, assist breeding programs in identifying PVY resistance, and to assist growers in developing cost effective, on-farm virus control strategies.
1b.Approach (from AD-416):
Training materials will be developed to help inspectors better identify virus infections. Improvements to post harvest test procedures will focus on lighting systems that may allow operations to move out of the field and into controlled environments that would allow more uniform growth and faster testing. An economic analysis of various post harvest test methods will provide certification agencies with cost savings projections if they choose to implement new testing procedures. Field and greenhouse evaluations of existing cultivars and breeding lines for their susceptibility to tuber necrosis and their reactions to all PVY strains will provide valuable risk assessment information. Regional trials of material should also identify new sources of resistance to PVY that can be introduced into breeding populations. Cost-benefit analyses will be conducted for each of the scientific recommendations in order to assist agencies in evaluating any proposed changes to the National PVY Management Plan. Proposal Co-Investigators will meet annually with stakeholders to ensure the research continues to address relevant issues and to discuss research findings and potential recommendations to modify the current PVY Management Plan.
The first year (2011) of national PVY trials using breeding lines from U.S. potato breeding programs was conducted in Idaho, New York, and Wisconsin. Results from New York and Idaho were analyzed through the winter and spring (2012) and show four breeding lines with high resistance (0-5% PVY) to all three strains of PVY. Wisconsin results have not yet been analyzed. The second year (2012) of this study has been planted and inoculated with PVY strains at all three locations. Breeders have been notified and are preparing a new set of minitubers for the 2013 and 2014 plantings. In the USDA-ARS Aberdeen Potato Breeding Program, a total of 56 parental lines and breeding lines with either Solanum tuberosum ssp. andigena or S. stoloniferum backgrounds have been sampled for molecular marker testing for the presence of Ryadg and Rysto PVY resistance genes. Test results will to add to the potato breeding database. This testing will also help with identifying additional breeding clones for PVY resistance bioassays. For development of training materials, leaf samples and photos were taken from post-harvest test plots and represent major varieties grown in the Pacific Northwest. The leaf samples were saved for and will be typed to PVY strain by use of a diagnostic RT-PCR test. The information collected will be posted to the grant project’s online picture gallery which can be used as a training manual. The research conducted contributes to Objective 4 of the in-house project.