Development of High Throughput Kasp SNP Markers for Wheat Curl Mite Resistance and Their Application in Marker-Assisted Breeding.

Viruses transmitted by the wheat curl mite (Aceria tosichella Keifer, WCM) have been a persistent concern to farmers and researchers for at least six decades. Yield loss caused by mite-virus complexes has been reported up to 100% at field level and up to 7% state wide. Texas A&M University developed hard red winter wheat variety TAM 112 has resistance to WCM. This study was conducted to map the WCM-resistant gene in TAM 112. The experiment tested 124 F5:7 recombinant inbreed lines (RILs) along with TAM 112, TAM 111, and susceptible check Karl 92. All of the wheat cultivars and lines were infested with WCM at the two-leaf stage and scored the first and second week after infestation of WCM. For genotyping data, DNA of RILs and parents were extracted and subjected to marker analysis. A total of 90,900 markers including SNPs, DArT, SSR, and STS were screened. Valid genotype data were utilized to construct the genetic map. All lines having the rye translocation 1AL.1RS showed resistance to WCM. In addition to 1AL.1RS, another WCM-resistant gene in TAM 112 was mapped on the short arm of chromosome 6D. The resistance gene was designated as CmcTAM112. Further study is necessary to differentiate CmcTAM112 from known curl mite colonization resistance genes, Cmc1 and Cmc4. Two closely linked array SNPs were converted into Kompetitive allele specific PCR (KASP) SNP for high throughput screening. These SNPs are promising for marker-assisted breeding as wheat curl mite screening is very time and money consuming.