Development of High Throughput SNPs for Host Plant Resistance in Wheat

Development and utilization of genetic markers play a crucial role in marker-assisted breeding of wheat cultivars with multiple stress tolerances. Arthropods and their transmitted viral diseases are major limiting factors for wheat production in the US Great Plains. The major biotic stresses include Greenbugs (GB), wheat curl mites (WCM) and its transmitted pathogen wheat streak mosaic virus (WSMV). However, available markers for these traits are not diagnostic across breeding populations. In this study, we used 90K single nucleotide polymorphism (SNP) array to identify new markers which are effective across different genetic backgrounds. Linked SNPs from the array were converted to Kompetetive Allele Specific PCR (KASP) markers. Here we report development and utilization of KASP assay for genotyping of these three resistance genes. Gb3 for GB resistance: Gb3 on chromosome 7DL shows a wide spectrum resistance to GB. This gene was identified from TAM112 and two closely linked flanking SNPs were identified and validated in a set of lines. Cmc_TAM112 for WCM resistance: In addition to the 1AL.1RS rye translocation in TAM 112 which confers resistance to WCM, a second WCM resistance gene from Ae. tauschii was mapped and two linked SNPs were validated with a set of lines. Wsm2 for WSMV resistance: Wsm2 was mapped on chromosome 3BS in CO960293-2 that is consistent with previous studies. A set of six closely linked SNPs that flank Wsm2 were validated in multiple breeding populations. Application of these closely linked markers allows breeders to increase selection efficiency.