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. Replacing 5366-21000-023-00D 01/2008
3. Progress Report
Three new potato varieties were released with collaborators of the Pacific Northwest (Tri-State) Potato Variety Development Program: Purple Pelisse, Crimson Red, and AmaRosa. Purple Pelisse is a unique fingerling potato variety having purple skin and dark purple flesh and is suitable for fresh market as well as for the production of chips having a bright purple color. Crimson Red is a variety with potatoes having bright-red skin and white flesh, few internal or external defects, and good culinary merit and is suitable for fresh market use. AmaRosa is a fingerling variety with red skin and flesh, and high culinary qualities, making it very suitable for fresh market usage. It also can be fried with a good retention of its red flesh color following processing. Additional research during FY 2010 included further fine-mapping of potato leafroll virus (PLRV) resistance from the potato wild species, Solanum etuberosum in collaboration with a researcher at the University of Idaho, Moscow, Idaho. Resistance to PLRV, a primary virus pathogen of potato, has been shown by our program to be highly heritable across four generations of backcrossing to cultivated potato, making it useful for the genetic enhancement of potato. A set of clones with Solanum stoloniferum background was also sent to a collaborator at Oregon State University to screen for SMT003, a marker closely linked to the potato virus Y (PVY) resistance gene, Rysto. This gene is reported to confer extreme PVY resistance, i.e. resistance to all PVY strains. Progeny of those clones with SMT003 and the associated Rysto resistance gene will be field screened for PVY resistance under high pressure and multiple strain conditions and resistant breeding clones will be assayed to assess the correlative value of SMT003 with PVY resistance. Use of the PLRV and PVY molecular markers in the breeding program have the potential to decrease the amount of time necessary to identify virus resistance in parents and progeny and therefore increase selection efficiency in the program. In addition, field evaluations of a family segregating for traits were 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. Research also was initiated with ARS and University of California-Riverside researchers to assess unique germplasm from our breeding program for resistance to the bacterium responsible for Zebra Chip disease and the insect (psyllid) responsible for its transmission to potato.
1. Identification of Molecular Markers Linked with Potato Leafroll Virus (PLRV) Resistance. Potato leafroll virus (PLRV) is a major pathogen of potato resulting in yield and quality losses to the U.S. potato industry. Molecular markers were identified that are more closely associated than previous markers with a durable and highly heritable resistance to PLRV derived from the potato species, Solanum etuberosum. These molecular markers will aid in identifying PLRV resistant individuals early in the breeding process, thereby speeding the development of PLRV resistant potato cultivars. The markers were identified by a collaborating University of Idaho faculty member using data and germplasm from ARS researchers at Aberdeen, Idaho.
Haynes, K.G., Wanner, L.A., Thill, C.A., Bradeen, J.M., Miller, J., Novy, R.G., Whitworth, J.L., Corsini, D.L., Vinyard, B.T. 2010. Common Scab Trials of Potato Varieties and Advanced Selections at Three U.S. Locations. American Journal of Potato Research. 86:261-276.