VALIDATION OF QTL HAP-6A-13 ASSOCIATED WITH GRAIN WEIGHT IN SPRING BREAD WHEATS

Abstract

This study was conducted to validate the quantitative trait locus (QTL) HAP- 6A-13, which was reported to be associated to grain weight in Spring bread wheat from the International Maize and Wheat Improvement Center (CIMMYT). To perform the validation, two Kompetitive Allele Specific PCR (KASP) markers were designed for the T/C and A/G single nucleotide polymorphisms (SNPs) comprising the QTL. The association of KASP markers with thousand kernel weight and grain yield was verified by genome-wide association study (GWAS) in four wheat collections. The two KASP markers showed significant association with thousand kernel weight and grain yield (P ≤ 0.05); in addition, 10 heterogeneous inbred families (HIF) were generated and thousand kernel weight, grain yield and other morphometric traits of the grain were evaluated. In contrast to the GWAS results, in the HIF evaluations the effect of the QTL HAP-6A-13 was significant (P ≤ 0.05) only in one HIF for thousand grain weight, and in three HIF for grain length, which demonstrates the difficulty of validating a QTL of minor effect in wheat.