ARS | Publication request: Characterization of Early Blight Resistance in Interspecific Potato Hybrids

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 2, 2010
Publication Date: August 17, 2010
Citation: Haga, E., Jansky, S.H., Halterman, D.A. 2010. Characterization of Early Blight Resistance in Interspecific Potato Hybrids [abstract]. 4th Annual Plant Breeding Meeting.

Technical Abstract: Early blight, caused by the fungal pathogen Alternaria solani Sorauer, is a serious foliar disease of potato and tomato worldwide. It is characterized by severe defoliation resulting in significant losses in yield. Fungicides are the main method of control; however, they are undesirable due to their negative economic, environmental, and health effects. Host resistance is the most optimal solution, yet cultivated varieties offer only a few sources of moderate resistance, most of which are associated with late maturity. Strong levels of resistance have been identified in wild species, and breeding efforts to introgress this resistance into cultivated potato offer promise in controlling the disease more sustainably. In order to understand the genetic basis of resistance, the wild species Solanum berthaultii (2n = 2x = 24) was selected for the development of several breeding populations through interspecific hybridization to cultivated haploids (2n = 2x = 24) of Solanum tuberosum. These populations, as well as several F2 and backcross generations, were evaluated for early blight development under field conditions in a major potato production area without fungicides using natural inoculum. Analysis of the data has revealed significant variation among families, as well as segregation within families, indicating high levels of potential for resistance breeding using this species. From these results, recommendations can be made for an efficient assessment strategy that balances the need for accuracy with the limitations of resource allocation. The data gathered is also being used to estimate heritability and inheritance patterns of this trait, which will be useful to breeders in selecting the appropriate methods for further population improvement.