The Exploitation Of Molecular Markers In The Potato Late Blight Resistance QTL Region

Potato (Solanum tuberosum L.), originated from Andean, is the fourth most important food crop which plays a very important role in food security in the world due to its high nutritional value and well-adaptation as well as high yield. However, it is infected by various pathogens. Late blight, caused by Phytophthora infestans, is the most devastating disease of potato. Late blight control currently relies on the application of chemical pesticides. Although this control method has played a significant role in prevention of late blight, but, at the same time, it also raises serious environment and human health concerns. In addition, the efficiency of chemical control is declining due to the evolution of Phytophthora infestans. Breeding for stable and sustained resistance has become a main strategy.In present research, based on the pervious study, we aim to complement and enrich markers in the QTL region that possess potato late blight resistance. The main results are as follows:1. Forty seven ESTs and candidate genes associated with late blight resistance were screened and14polymorphic bands in population B3C1HP were obtained.2. The resistant and susceptible pools to late blight were built by Using BSA. Meanwhile, the gene pools were also constructed according to the appearance or absence of the markers (DMC42144af and DMC42152bf), which were previously reported to link with the QTL regions. In total, four gene pools named R, S, A and B were developed. There were26polymorphic bands obtained through amplification with208pairs of AFLP markers in the four gene pools. Ten of these polymorphic bands appeared in both two gene pools, which were then retrieved and sequenced. Primers were designed according to the sequencing results to detect the polymorphism in the B3C1HP population.3. The original data about these polymorphic bands were integrated into the B3C1HP population. In total, eight tags were located in the Ⅰ、Ⅳ、Ⅵ、Ⅸ and Ⅻ chromosome of B3C1HP maternal linkage map, two of them were located on the dPI09a confidence interval of chromosome Ⅸ. The markers mapped could be applicable for fine-mapping the QTL regions.