QTL mapping of spike fertility index in bread wheat

Abstract Spike fertility index (SF) is a trait easily measured at maturity and strongly associated with the number of grains per unit area. In order to identify genomic regions involved in SF control, a biparental (Baguette 10 × Klein Chajá) population of 80 recombinant inbred lines (RIL) was used. Seven field trails were conducted to determine the SF BLUP value per RIL. RILs were genotyped using a commercial chip (Axiom® 35K SNP Wheat Breeder's Array, Affimetrix). A linkage map was constructed with 857 SNP markers, and SF QTL mapping was performed. The narrow-sense heritability of SF was 0.89. Three genomic regions (QTL) associated with SF were found on chromosomes 2D, 4A, and 7A. The proportion of genetic variation explained by these three QTL was 32%, with no significant epistatic interaction between QTL.