ARS | Publication request: Examination of Early Blight Resistance Derived From S. Raphanifolium

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. Examination of Early Blight Resistance Derived From S. Raphanifolium [abstract]. Plant Breeding Conference Proceedings. p. 19.

Technical Abstract: Early blight of potato (Solanum tuberosum L.), caused by Alternaria solani is a major cause of economic losses in many potato growing regions. Growers and breeders are interested in the development of potato cultivars with resistance to early blight as a means to decrease usage of fungicide applications. Using wild species germplasm in breeding programs, which is diverse and accessible, makes it a desirable resource to examine disease resistance characteristics. The diploid wild species S. raphanifolium has shown increased levels of early blight resistance which could be incorporated into cultivated potato. Eight haploid-wild species hybrid families were created in a genetic study using US-W4, a diploid clone (2n=2x=24) of the cultivated potato and S. raphanifolium, a wild (2n=2x=24) Solanum species. Families were grown in a field setting for two years and rated for early blight resistance using the Horsfall-Barratt 0-11 scale. Preliminary results based on 2008 field data showed significant differences among families. Haploid-wild species hybrid families that were created by backcrosses to the wild species parent exhibited better field resistance to early blight than families created by backcrosses to the cultivated potato. Of the overall variability present in the field, 45% was caused by differences among S. raphanifolium families. No significant differences were observed between replications. Field data for 2009 are currently being collected and will be incorporated into the two year study at the end of the growing season.