QTLs and candidate genes for downy mildew resistance conferred by interspecific grape (V. vinifera L. x V. amurensis Rupr.) crossing

Considering the economic importance of grape (Vitis spp.), breeding for downy mildew (P. viticola) resistance has made great progress in the last two decades. However, the genetic and genomic information of resistance against grape downy mildew remain largely unknown. In this study, we described the quantitative trait loci (QTL) and candidate genes for downy mildew resistance in susceptible V. vinifera cv. 'Red Globe' and V. amurensis Rupr. cv. 'Shuangyou'. Two novel QTLs for downy mildew resistance were mapped on linkage group (LG) 15, which have been named Rpv25 and Rpv26, respectively. Candidate gene analysis found that three cysteine-rich receptor protein kinase (CRK) near to two N genes in the Rpv25 locus, and a gene encoding LRR (leucine-rich repeat)-RLK (receptor-like protein kinases) family protein in Rpv26 locus may be associated to downy mildew resistance in current climatic conditions. The results of the present study provide useful information for grape downy mildew disease resistance breeding.