Development and Validation of Kasp Markers for Marker-Assisted Selection of Wsm2 in Wheat.

Wheat Streak Mosaic Virus (WSMV: Tritimovirus. Potyviridae) is a devastating disease in wheat (Triticum aestivum L.) in the Great Plains of North America. A recently identified WSMV resistance gene, Wsm2, mapped to the short arm of chromosome 3B in germplasm line CO960293-2, confers a high level of resistance. Breeding for wheat cultivars with resistance provides a cost effective and environmentally safe approach for combating the disease. Marker-assisted selection (MAS) is a powerful genetic tool for breeding for a trait like WSMV resistance that is difficult to phenotype. The availability of markers for Wsm2 will serve to facilitate selection of lines for cultivar development. The aim of this study was to develop closely linked high-throughput single nucleotide polymorphism (SNP) markers for Wsm2 in wheat. This was achieved via high density mapping using the 90K Infinium iSelect SNP assay in a recombinant inbred line (RIL) population derived from the cross CO960293-2/TAM 111. A set of six converted Kompetitive Allele Specific PCR (KASP) markers from SNPs flanking Wsm2 were mapped within 2 cM on chromosome 3BS. Genetic map of Wsm2 and two flanking SNPs were confirmed in two other breeding populations. The KASP markers identified in this study can be utilized in future genetic studies of Wsm2 and will be useful in MAS for germplasm and cultivar development.