Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/27/2006
Publication Date: 1/1/2007
Citation: Novy, R.G., Miller, J.S., Porter, L., Whitworth, J.L., Lozoya-Saldana, H. 2007. Segregation of progeny of Solanum tuberosum subsp. andigena for foliar and tuber resistance to late blight.. American Journal of Potato Research. 84(1): 106-107
Technical Abstract: Breeding solely for foliar resistance to late blight without emphasis on tuber resistance has the potential to exacerbate tuber infection. Wild potato species are valuable sources of foliar and tuber blight resistance. However, most species are difficult to sexually hybridize with cultivated potato and require the use of 2n gametes or ploidy manipulations. Solanum tuberosum subsp. andigena is closely related to and hybridizes readily with cultivated potato (S. tuberosum subsp. tuberosum). Clones of andigena were identified having combined resistance to both foliar and tuber infection by late blight following evaluations using detached leaf and tuber inoculation assays. Field evaluations in the U.S. confirmed their resistances. Two late blight resistant clones of andigena were hybridized with cultivated potato. Four hybrid families, representing 400 clonal individuals, were concurrently screened for foliar resistance at Bonners Ferry, Idaho and in the Toluca Valley of Mexico in 2005. Tuber blight resistance of these hybrid progeny also were assessed using inoculation assays. Segregation for foliar late blight resistance was observed in all four families at Bonners Ferry, Idaho. However, three of these four families did not have useful levels of foliar late blight resistance at the Toluca Valley site. The three susceptible families had a Mexican-derived andigena parent, whereas the remaining resistant family originated from the use of an andigena accession from Colombia. Our results point to the need for breeders to screen in Toluca Valley, with its complex pathotypes of Phytopthora infestans, to ensure that late blight resistance being used in a breeding program will be durable.