Development of Kaspar SNP Markers for Host Plant Resistance to Biotic Stress in Wheat

Development and utilization of genetic markers is crucial to success in marker-assisted selection (MAS) for wheat cultivars tolerant to multiple stresses. Arthropods and their transmitted viral diseases are major limiting factors for wheat production in the U.S. Great Plains. These biotic stresses include Greenbugs (GB), wheat curl mites (WCM) and its transmitted disease wheat streak mosaic virus (WSMV). However, available markers for these traits are not diagnostic across breeding populations. In this study, we used genotyping data derived from 90,000 single nucleotide polymorphism (SNP) array to identify new diagnostic markers which are effective across diverse germplasm lines or cultivars and breeding populations. Linked SNP markers from the 90K array were converted to KASPar SNP markers for validation and application. The development and utilization of KASPar assay for three resistance genes was reported here. Gb3 for GB resistance: Gb3 has the most wide spectrum resistance to GB. This gene was mapped on chromosome 7DL in TAM 112 and linked flanking SNP markers were validated. Cmc_TAM112 for WCM resistance: In addition to the 1AL.1RS rye translocation in TAM 112, a second WCM resistance gene from Ae. tauschii was mapped and linked flanking SNP markers were validated. Wsm2 for WSMV resistance: Wsm2 was fine mapped on chromosome 3BS in CO960293-2. Closely linked high throughput SNP markers were validated for MAS of Wsm2 in different populations. Applications of these tightly linked markers allow breeders to increase selection efficiency and accelerate the breeding process, and thus quickly deliver improved cultivars to wheat producer.