Mining the stable quantitative trait loci for agronomic traits in wheat (Triticum aestivumL.) based on an introgression line population

Background Human demand for wheat will continue to increase together with the continuous global population growth. Agronomic traits in wheat are susceptible to environmental conditions. Therefore, in breeding practice, priority is given to QTLs of agronomic traits that can be stably detected across multiple environments and over many years. Results In this study, QTL analysis was conducted for eight agronomic traits using an introgression line population across eight environments (drought stressed and well-watered) for 5 years. In total, 44 additive QTLs for the above agronomic traits were detected on 15 chromosomes. Among these,qPH-6A,qHD-1A,qSL-2A,qHD-2DandqSL-6Awere detected across seven, six, five, five and four environments, respectively. The means in the phenotypic variation explained by these five QTLs were 12.26, 9.51, 7.77, 7.23, and 8.49%, respectively. Conclusions We identified five stable QTLs, which includesqPH-6A,qHD-1A,qSL-2A,qHD-2DandqSL-6A. They play a critical role in wheat agronomic traits. One of the dwarf genesRht14,Rht16,Rht18andRht25on chromosome 6A might be the candidate gene forqPH-6A. TheqHD-1AandqHD-2Dwere novel stable QTLs for heading date and they differed from known vernalization genes, photoperiod genes and earliness per se genes.