Submitted to: Plant Breeding Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: July 31, 2009
Publication Date: August 3, 2009
Citation: Haga, E., Jansky, S.H., Halterman, D.A. 2009. Genetic Characterization of Early Blight Resistance in Interspecific Potato Hybrids [abstract]. Plant Breeding Conference Proceedings. p. 9.
Early blight, caused by the fungal pathogen Alternaria solani Sorauer, is a serious foliar disease of potato and tomato worldwide. It is characterized by substantial yield loss resulting from severe defoliation, especially under hot, humid conditions. Fungicides are the main method of control, however they are undesirable due to their economic, environmental, and health consequences. 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, are being evaluated in a major potato production area for early blight development under field conditions without fungicides using natural inoculum. The data gathered will be used to estimate the heritability and inheritance patterns of early blight resistance derived from S. berthaultii. Preliminary data from 2008 show variation among families, as well as significant segregation within families, indicating high levels of potential for resistance breeding using this species.