Whole genome mapping in a wheat doubled haploid population using SSRs and TRAPs and the identification of QTL for agronomic traits

Abstract

Genetic maps are useful for detecting quantitative trait loci (QTL) associated with quantitative traits and for marker-assisted selection (MAS) in breeding. In this research, we used the wheat × maize method to develop a doubled haploid (DH) population derived from the synthetic hexaploid wheat (SHW) line TA4152-60 and the North Dakota hard red spring wheat line ND495. The population consisted of 213 lines, of which a subset of 120 lines was randomly selected and used to construct linkage maps of all 21 chromosomes and for QTL detection. The whole genome maps consisted of 632 markers including 410 SSRs, 218 TRAPs, 1 RFLP, and 3 phenotypic markers, and spanned 3,811.5 cM with an average density of one marker per 6.03 cM. Telomere sequence-based TRAPs allowed us to define the ends of seven linkage groups. Analysis revealed major QTLs associated with the traits of days to heading on chromosomes 5A and 5B, plant height on chromosomes 4D and 5A, and spike characteristics on chromosomes 3D, 4A, 4D, 5A and 5B. The DH population and genetic map will be a useful tool for the identification of disease resistance QTL and agronomically important loci, and will aid in the identification and development of markers for MAS.