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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Genetic Improvement for Fruits & Vegetables Laboratory » Research » Publications at this Location » Publication #292287

Title: Two cycles of recurrent maternal half-sib selection reduce foliar late blight in a diploid hybrid Solanum phureja-S. stenotomum population by two-thirds

item Haynes, Kathleen
item QU, XINSHUN - Pennsylvania State University
item CHRIST, BARBARA - Pennsylvania State University

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/29/2013
Publication Date: 5/1/2014
Publication URL:
Citation: Haynes, K.G., Qu, X., Christ, B.J. 2014. Two cycles of recurrent maternal half-sib selection reduce foliar late blight in a diploid hybrid Solanum phureja-S. stenotomum population by two-thirds. American Journal of Potato Research. 91:254-259.

Interpretive Summary: Late blight is a serious disease of potatoes worldwide. Under conditions favorable to disease development, fungicides must be applied at five-day intervals. Late blight resistance has been identified in potato species closely related to the cultivated potato but additional knowledge is required to effectively transfer that resistance to cultivated potato. We selected late blight resistant plants over a six year period in the breeding program. Breeding to improve late blight resistance in these species has resulted in a two-thirds reduction in the amount of late blight present under high disease pressure after two cycles of selection for resistance. Additional improvements in the levels of late blight resistance are expected with additional breeding. This information will benefit potato breeders working to develop late blight resistant varieties. The development of late blight resistant varieties would greatly benefit the environment and producers economic return.

Technical Abstract: Foliar late blight, caused by Phytophthora infestans, is an important disease problem worldwide. Foliar resistance to late blight was found in a hybrid population of the cultivated diploid species Solanum phureja-S. stenotomum (phu-stn). The objective of this study was to determine if resistance to late blight could be improved by recurrent maternal half-sib selection in the phu-stn population. Four clones from each of 72 maternal half-sib families plus the check cultivar ‘Atlantic’ were evaluated for late blight resistance in replicated field trials in Pennsylvania. The most late blight resistant clone from each of the 72 families was randomly intermated to advance the population. The cycle 1, 2, and 3 populations were evaluated in 1996-1997, 2003-2004, and 2009-2010, respectively. Percent infected foliage was recorded several times towards the end of the growing season and used to compute area under the disease progress curve (AUDPC). Mean AUDPC was 652 (cycle 1), 556 (cycle 2), and 276 (cycle 3), whereas the mean AUDPC of ‘Atlantic’ ranged from 775-863 each cycle. Narrow-sense heritability for resistance was estimated as 0.78, 0.77, and 0.80 in cycles 1, 2, and 3, respectively. Recurrent maternal half-sib selection continues to improve the levels of resistance to late blight in this diploid population with no adverse effect on the amount of additive genetic variance. Additional improvements for late blight resistance are likely to occur if this approach is continued.