Wheat Curl Mite Resistance in Hard Winter Wheat in the US Great Plains

Abstract

Viral diseases transmitted by wheat curl mite (WCM, Aceria tosichella Keifer) have been a persistent concern to farmers and researchers for at least six decades. Yield losses caused by mite–virus complexes up to 100% at the field level have been reported in several states of the Great Plains. This study was conducted to evaluate the level of resistance of hard winter wheat (Triticum aestivum L.) germplasm lines and cultivars to WCM. Four sets of wheat lines from 2014 trials were screened, including 40 lines from the Northern Regional Performance Nursery, 40 lines from the Southern Regional Performance Nursery, 40 Texas elite wheat lines, and 52 cultivars and elite breeding lines. Two different mite collections, Texas WCM collection 1 (TWCMC1) and Texas WCM collection 2 (TWCMC2), were used to screen wheat lines. All cultivars and lines were infested with WCM at the two‐leaf stage and scored on the first and second week after the second infestation. A total of 43 wheat lines and cultivars showed resistance to TWCMC1, but only 18 of them consistently exhibited resistance to TWCMC2, which is virulent to wheat‐rye translocation 1AL.1RS. All the lines having the ‘Amigo’ 1AL.1RS translocation (Cmc3) across the four tests showed resistance to TWCMC1 but not to TWCMC2. Among the 22 lines with ‘TAM 112’ in their pedigree, 19 lines were resistant to TWCMC1, but only a subset of 12 showed resistance to TWCMC2. TWCMC2 and mite collections from Kansas and Nebraska were differentiated based on the high‐resolution melting curves and sequence analysis of mite DNA. Results from this study will help wheat breeders and geneticists to select WCM‐resistant parental lines for their breeding programs.