SNP-based identification of QTLs for thousand-grain weight and related traits in wheat 8762/Keyi 5214 DH lines

Abstract

As important yield-related traits, thousand-grain weight (TGW), grain number per spike (GNS) and grain weight per spike (GWS) are crucial components of wheat production. To dissect their underlying genetic basis, a double haploid (DH) population comprised of 198 lines derived from 8762/Keyi 5214 was constructed. We then used genechip to genotype the DH population and integrated the yield-related traits TGW, GNS and GWS for QTL mapping. Finally, we obtained a total of 18 942 polymorphic SNP markers and identified 41 crucial QTLs for these traits. Three stable QTLs for TGW were identified on chromosomes 2D (QTgw-2D.3 and QTgw-2D.4) and 6A (QTgw-6A.1), with additive alleles all from the parent 8762, explaining 4.81–18.67% of the phenotypic variations. Five stable QTLs for GNS on chromosomes 3D, 5B, 5D and 6A were identified. QGns-5D.1 was from parent 8762, while the other four QTLs were from parent Keyi 5214, explaining 5.89–7.08% of the GNS phenotypic variations. In addition, a stable GWS genetic locus QGws-4A.3 was detected from the parent 8762, which explained 6.08–6.14% of the phenotypic variations. To utilize the identified QTLs, we developed STARP markers for four important QTLs, Tgw2D.3-2, Tgw2D.4-1, Tgw6A.1 and Gns3D.1. Our results provide important basic resources and references for the identification and cloning of genes related to TGW, GNS and GWS in wheat.