1a. Objectives (from AD-416)
Objectives of this research are the development of potato varieties and germplasm with disease and pest resistances, reduced sugar accumulation, reduced need for production inputs, and enhanced nutritional qualities. Targets for resistance breeding are the major diseases and pests affecting potato production in the western United States. Many of these diseases and pests are nationally important, with germplasm and varieties from our program also benefitting potato producers outside the western United States as well. Objective 1: Develop potato germplasm with beneficial traits and make available to the potato industry, breeders, and geneticists. Objective 2: Develop enhanced potato varieties that benefit U.S. potato producers and consumers, including russets (fresh market and processing), long whites (processing), round whites (chipping), and specialty (red-skinned and yellow-fleshed), with emphasis on disease and pest resistance, reduced sugar accumulation, reduced need for production inputs, and enhanced nutritional qualities. Objective 3: Develop marker-assisted selection (MAS) protocols for potato traits, with an emphasis on pathogen and pest resistances. Objective 4: Characterize foliar and tuber responses of potato varieties to infection by newly identified strains of potato virus Y (PVY), and identify new sources of resistances to these PVY strains useful to potato breeders.
1b. Approach (from AD-416)
This research, performed under institutional biosafety policies, will benefit the western U.S. potato industry by developing new potato varieties that will maintain the economic viability and competitiveness of this region in an age of expanding global competition. This will be accomplished by producing new potato varieties with improved agronomic characteristics, nutritional qualities, disease/pest resistances, and a reduced need for production inputs such as water and nitrogen. Desired traits will be acquired from wild relatives of the cultivated potato and from germplasm of other potato breeding programs within and outside of the U.S. Identified parental material will be hybridized with potato breeding clones and varieties adapted to the irrigated environments of the western U.S. Progeny of hybridizations will be evaluated, performance data collected, and superior individuals selected and advanced in the program for release as potato varieties with enhanced attributes. Newer technologies, such as marker-assisted selection, will be used to facilitate the development of enhanced potato varieties.
3. Progress Report
Potato cultivar ‘Palisade Russet’, notable for having resistance to late blight and for having desirable processing characteristics (low incidence of sugar ends), was released. Late blight is a devastating disease of potato with the potato varieties utilized by the U.S. industry being susceptible to the disease, with protection against late blight being conferred by the use of fungicides. Palisade Russet has shown high specific gravities (tuber starch content) in western production regions of the U.S. which may limit its acceptance by the western processing industry. However, in potato production regions with inherently low specific gravities, Palisade Russet could have potential as a processing cultivar. In addition, the disease resistances of Palisade Russet make it a good candidate for organic production, or for use by growers seeking reduced pesticide inputs. Additional research during FY 2011 included genetic mapping of potato leafroll virus (PLRV) resistance from the potato wild species, S. etuberosum in collaboration with a researcher at the University of Idaho. Resistance to PLRV is not present in potato varieties grown by the U.S. industry and the identification of molecular markers closely linked to PLRV resistance will be useful in accelerating the development of PLRV resistant varieties. Field evaluations of a family segregating for traits were also conducted as part of a national research effort termed “SolCAP” to link genes important in carbohydrate and vitamin biosynthesis in potato with molecular markers to aid in the incorporation of marker-assisted selection in potato breeding. This project also contributed advanced breeding clones and varieties for the National Fry Processing Trial (NFPT) which was initiated in 2011 to identify processing varieties having low acrylamide that could be rapidly adopted by the U.S. potato processing industry. Our project also oversaw the Idaho trial site of the 2011 NFPT. Research initiated with University of California-Riverside researchers identified several potato breeding clones from our program having psyllid resistance and putative resistance to the bacterium responsible for Zebra Chip disease. This is notable in that potato varieties currently utilized by industry have shown no or little resistance to Zebra Chip, making identified resistant clones useful for developing Zebra Chip resistant potato varieties. This research was accepted for publication in the Crop Protection Journal. Replicated trials also were initiated in Idaho with our program as well as in New York and Wisconsin to screen potato breeding lines for potato virus Y (PVY) resistance, with evaluations of foliar and tuber expression of infection with PVY being conducted. These trials, to be repeated over a four year period, are designed to evaluate three strains of PVY, one of which is known to cause tuber necrosis.
1. Release of Palisade Russet, a late blight resistant potato cultivar having a low incidence of tuber sugar ends and high specific gravity. Late blight is a devastating disease of potato with the major potato varieties grown in the U.S. being susceptible and requiring applications of fungicides to protect against the disease. Palisade Russet, a late blight resistant cultivar with high tuber starch content and a low incidence of sugar ends of tubers (important to the processing industry), originated from ARS' breeding program at Aberdeen, Idaho, and was developed and released in collaboration with university researchers in the states of Idaho, Oregon, and Washington. Palisade Russet can be grown in potato production regions of the U.S. where low starch content in tubers is problematic for the potato processing industry. The use of Palisade Russet as a cultivar can provide host plant resistance to late blight which can be a component of an integrated approach for controlling late blight and reducing pesticide usage for greater sustainability in potato production.
2. Publication of plant disease feature article on Potato virus Y (PVY). The appearance of PVY strains in the 1990's that can cause tuber necrosis is a prime concern of the industy. The strains cause not only a yield reduction, but the tuber necrosis from the new strains adds a quality effect as well. No pesticides exist that act quickly enough to stop the aphid vector from spreading these strains. Two ARS researchers at Aberdeen, ID, and Ithaca, NY, were instrumental in initiating the survey and securing grant funds from USDA-APHIS and the National Potato Council. An ARS scientist at Aberdeen, ID, was a co-author of the Plant Disease feature article which recommends fundamental changes to industry practices to combat the spread of these new PVY strains. This publication addresses the results from a U.S./Canada three year survey of PVY in seed potato lots. It was the first comprehensive survey conducted in seed or commercial potatoes.
Novy, R.G., Whitworth, J.L., Stark, J.C., Love, S.L., Corsini, D.L., Pavek, J.J., Vales, M.I., James, S.R., Hane, D.C., Shock, C.C., Charlton, B.A., Brown, C.R., Knowles, N.R., Pavek, M.J., Brandt, T.L., Gupta, S., Olsen, N. 2010. Clearwater Russet: A Dual-Purpose Potato Cultivar with Cold Sweetening Resistance, High Protein Content, and Low Incidence of External Defects and Sugar Ends. American Journal of Potato Research. 87:458-471.