Kernel length (KL) is one of the components determining grain weight (GW) in wheat. In this study, we firstly detected a putative locus on chromosome arm 2BL from a mutant BLS2 with long kernels using a Bulked Segregant Analysis (BSA) combined with a 60 K SNP array. This putative locus was then confirmed as a major and stable QTL based on linkage mapping. The locus, Qkl.sau-BC-2B.1, was mapped in an interval of 0.4 cM, and phenotypic variance explained by it varied from 17.01 to 30.53% across different environments. Effects of this locus was further verified in a second population. The positive allele of the locus could significantly increase hundred-kernel weight and prolong anthesis date, but it did not affect plant height, tiller number, spike length, and spikelet number per spike. Expression and sequencing analyses identified TraesCS2B02G478100, possessing a G to C transition variation leading to an amino acid change, as the likely candidate gene underlying the locus. Further, a new model for analyzing the genetic basis of yield-related traits was proposed. Taken together, our results provide a foundation for subsequent gene mining and breeding utilization of this promising QTL for KL.

wheat  /  kernel length  /  BSA  /  60K SNP array  /  QTL mapping