Developing Kasp Markers for Biotic Stress Tolerances in Wheat.

Arthropods and their transmitted viral diseases are major limiting factors for wheat production in the U.S. Great Plains and many other areas in the world. Development and utilization of high throughput molecular markers are crucial in marker-assisted selection (MAS) to improve wheat tolerance to multiple stresses. These biotic stresses include Greenbug (GB), Hessain fly (HF), wheat curl mite (WCM) and wheat streak mosaic virus (WSMV). In this study, we used genotyping data from the 90,000 single nucleotide polymorphism (SNP) array or genotyping-by-sequencing to identify new diagnostic and effective markers across diverse germplasm lines. Linked SNPs were converted to Kompetitive Allele Specific PCR (KASP) array for high throughput screening. The KASP assays for five resistance genes were developed and evaluated in this study. Gb3 and Gb7 have the most widest spectrum resistance to GB. Both were mapped on chromosome 7DL. Cmc_TAM112 for WCM resistance from Ae. tauschii was mapped and linked flanking SNP markers were validated. Wsm2 for WSMV resistance was fine-mapped on chromosome 3BS, and H32 with HF resistance was mapped onto 3DL. Closely linked high throughput KASP SNPs were validated for MAS in different populations. Applications of these tightly linked KASP SNPs allow breeders to increase selection efficiency and accuracy.