Genetic Mapping and Kasp Marker Development for Wheat Curl Mite Resistance in TAM112.

In the US Great plains, wheat curl mite (Aceria tosichella Keifer, WCM) and the transmitted wheat streak mosaic virus (WSMV) seriously decrease wheat production. Significant yield loss occurs at large geographic areas, while possible complete yield lost on field level. Breeding for wheat cultivar with genetic control of wheat curl mite and wheat streak mosaic virus is a viable and economically feasible way to reduce such yield loss. This study was conducted to map the WCM resistant genes in hard red winter wheat variety TAM 112 using the 90K Illumina Infinium iSelect single nucleotide polymorphism (SNP) assay. We tested 124 F5:7 recombinant inbreed lines (RIL) derived from the cross of TAM112/TAM111, along with TAM 112, TAM 111, and susceptible check Karl 92. All the lines were infested with WCM at the two-leaf stage and were scored on the first and second week after infestation of WCM. Linkage map was constructed with 4815 SNPs and 19 simple sequence repeat (SSR) and sequence-tagged site (STS) covering 21 chromosomes. In the present study, in addition to the rye translocation 1AL.1RS showing resistance to the TXWCM collection 1 (TXWCMC1), another WCM resistant gene in TAM 112 was derived from Ae. tauschii line PI 268120 that is resistant to a more virulent collection, TXWCMC2. However, all tested lines with 1AL.1RS were susceptible to TXWCMC2. A total of four SNPs flanking 6DS gene were mapped within 5 cM. The two tightly linked SNPs were converted into Kompetitive Allele Specific PCR (KASP) markers and validated in advanced wheat lines from Texas and other breeding programs. These tightly linked markers should be useful for marker-assisted selection for WCM resistance in many genetic backgrounds.