Validation of quantitative trait loci for grain quality-related traits in a winter wheat mapping population

Abstract

Validating positions and effects of putative quantitative trait loci (QTL) is an important step before employing linked markers in marker-assisted selection (MAS) or conducting finer-scale mapping. Previously, QTL for grain quality traits were identified in a population of 185 doubled haploid (DH) winter wheat (Triticum aestivum L.) lines developed from the cross CO940610/’Platte’. Clusters of QTL for grain quality traits were detected on chromosomes 1B, 6B, and 7B. Our objectives were to (1) confirm the previously identified QTL, using recombinant inbred line (RIL, n = 186) and BC3F2:3 (n = 35) populations developed from the same parents; and (2) test the effects of combinations of alleles at three marker loci in the target chromosome regions. Field trials were conducted in two Colorado environments for the RIL population in 2009/10 and three environments for the BC3F2:3 population in 2012/13. Most QTL previously detected for grain quality traits on 1B, 6B, and 7B were repeated in either the RIL or BC3F2:3 populations, although these QTL were not robust across populations and environments. However, the QTL for grain ash concentration (Gac) on 7B was detected in all environments and populations, with Platte contributing the higher value allele. The BC3F2:3 lines with the allelic combination predicted to have higher grain protein concentration (Gpc) surpassed the lowest predicted combination in one of three environments investigated. Based on these evaluations, marker Bx7-MAR on 1B and the regions around markers Xwmc182a on 6B and Xwmc182b on 7B are recommended for further research for improving grain quality traits.