1a. Objectives (from AD-416):
Improve levels of disease resistance to foliar and soil-borne pathogens in potatoes. Improve processing and nutritional quality in potatoes through breeding and selection of superior germplasm. Evaluate advanced selections through replicated field trials prior to naming and release to stakeholders.
1b. Approach (from AD-416):
Use recurrent selection to improve diploid populations for disease resistances and processing quality. Use parental line breeding to improve tetraploid populations for disease resistances, processing quality, nutritional quality. Transfer these traits from improved diploids to the tetraploid level via 4x-2x crosses. Develop markers to facilitate introgression of desirable genes or deletion of undesirable genes from related species into commercial germplasm.
3. Progress Report:
Crosses were made in the fall and the spring for enhanced nutritional content, nitrogen uptake efficiency, processing potential and late blight resistance. Open-pollinated seed were harvested from the field from the high specific gravity cycle four population and from doubled monoploid families. Second year field generation germplasm was distributed to FL, NC, PA, NY and ME for evaluation and selection. Potato germplasm incorporating late blight resistance from several genetically diverse sources was screened for resistance in the field. A fertility study was initiated to develop fertilizer recommendations for a recently released variety. The orange-flesh trait in potatoes was found to be due to high levels of zeaxanthin; the yellow-flesh trait to high levels of lutein and other carotenoids.
1. Heat tolerant potato released. Commercial potato cultivars are susceptible to tuber internal heat necrosis. ARS released ‘Elkton’, a new potato chipping variety for the southeast. In 19 trials over several years and locations in FL, marketable yield of Elkton was 113% of the standard chipping variety ‘Atlantic’. Elkton has high specific gravity, good chip color when processed directly from the field, and is resistant to internal heat necrosis, a major defect in Atlantic. It is also moderately resistant to common scab, early blight and Verticillium wilt. 'Elkton' will reduce grower losses to internal heat necrosis while maintaining yield potential.
2. Genetic variation for potato micronutrients. Micronutrients are crucial to healthy growth and development, yet a large proportion of the world’s population suffers from micronutrient deficiencies. Biofortification of staple foods has tremendous potential to alleviate these deficiencies. ARS and University scientists identified large genetic variation for copper, iron, manganese, and zinc in potatoes, suggesting that the micronutrient content of potatoes can be improved through breeding. Potato production in developing countries is increasing rapidly, and therefore, biofortification of potatoes for essential micronutrients may be feasible.
Haynes, K.G., Yencho, G.C., Clough, M.E., Henninger, M.R., Sterrett, S.B. 2012. Genetic variation for potato tuber micronutrient content and implications for biofortification of potatoes to reduce micronutrient malnutrition. American Journal of Potato Research. 89:192-198.