Association Mapping of Quantitative Trait Loci for Agronomic Traits in a Winter Wheat Collection Grown in Kazakhstan

Abstract

Central Asia is an important region for the growth of winter wheat, with a cultivation area of more than 15 million hectares (ha). However, the average yield is approximately 3 tons per ha, which is significantly lower than that in developed countries. Therefore, the development of new competitive high-yielding cultivars, including those based on the application of modern molecular genetics tools, is a key priority in winter wheat breeding projects. One of these tools is the result of the identification of new genes and quantitative trait loci (QTLs) for agronomic traits using diverse germplasm panels and genome-wide association studies (GWAS). In this work, a panel of winter wheat accessions was assembled using 115 accessions from Central Asia and 162 samples from other regions of the world. The GWAS, based on a two-year field evaluation of the collection in Kazakhstan’s southern and southeastern regions and 10,481 polymorphic SNP (single-nucleotide polymorphism) markers, allowed for the detection of 173 stable QTLs in nine studied agronomic traits. A survey of the published scientific literature suggests that 23 of these 173 stable QTLs have locations similar to those of previously reported QTLs, supporting the robustness of the research. In addition, 221 and 162 accessions surpassed local standards for grain yield at Kazakhstan’s southern and southeastern stations, respectively. Therefore, this study is an additional contribution to the identification of new QTLs for key agronomic traits and valuable genetic lines in winter wheat breeding projects.