Molecular markers for late blight resistance breeding of potato: an update

Late blight is the most devastating disease of the potato crop that can be effectively managed by growing resistant cultivars. Introgression of resistance ( R ) genes/quantitative trait loci ( QTL s) from the S olanum germplasm into common potato is one of the plausible approaches to breed resistant cultivars. Although the conventional method of breeding will continue to play a primary role in potato improvement, molecular marker technology is becoming one of its integral components. To achieve rapid success, from the past to recent years, several R genes/ QTL s that originated from wild/cultivated S olanum species were mapped on the potato genome and a few genes were cloned using molecular approaches. As a result, molecular markers closely linked to resistance genes or QTL s offer a quicker potato breeding option through marker‐assisted selection ( MAS ). However, limited progress has been achieved so far through MAS in potato breeding. In near future, new resistance genes/ QTL s are expected to be discovered from wild S olanum gene pools and linked molecular markers would be available for MAS . This article presents an update on the development of molecular markers linked to late blight resistance genes or QTL s by utilization of S olanum species for MAS in potato.