1a. Objectives (from AD-416):
The goal of this proposal is to characterize Rlretb, a gene for resistance to potato leafroll virus (PLRV) from the potato species Solanum etuberosum, and identify molecular markers tightly linked to Rlretb that would be useful for marker-assisted selection and for the eventual cloning of the gene.
1b. Approach (from AD-416):
The ARS potato breeding and pathology program at Aberdeen, Idaho will conduct field screening for resistance to PLRV and greenhouse grafting studies evaluations that will elucidate the mechanisms of resistance to potato leafroll virus conferred by Rlretb. Research responsibilities also will include hybridization to synthesize diploid populations segregating for Rlretb, which would be useful for the fine mapping of this gene.
3. Progress Report:
The research conducted contributes to parent project Objective 1: "Develop enhanced potato germplasm and varieties for the most important market classes for the western United States, with emphasis on recurrent and emerging disease and pest resistance (late blight, Potato mop top virus, Potato leafroll virus, Potato virus Y, emerging cyst nematodes, and Zebra Chip), reduced sugar and acrylamide accumulation, reduced production inputs (nitrogen and water), and enhanced nutritional qualities (vitamin C and protein)" and 2: "Devise marker-assisted selection (MAS) protocols to accelerate breeding for resistance to recurrent and emerging pathogens and pests (Potato virus Y, Potato leafroll virus, and potato cyst nematode) that impact the western United States. Thirty-five breeding clones representing a family segregating for markers linked to the Rlretb gene for potato leafroll virus (PLRV) resistance are being maintained by our project. Clone response to PLRV infection, important for mapping of the Rlretb gene, was previously conducted by our project. Tubers of these 35 clones were sent from our program for establishment in tissue culture to provide pathogen-free plantlets and to ensure their long-term maintenance.