Genome-Wide Linkage Mapping of QTL for Yield Component in UI Platinum/Sy Capstone Double Haploid Population.

Days to heading, plant height, yield components and yield-related physiological traits are important parameters influencing wheat grain yield.  The objective of this study was to identify QTL associated with these traits using high-density genetic linkage map in a spring wheat double haploid population derived from a cross between ‘UI Platinum’ and ‘SY Capstone’. The DH population was genotyped using the wheat 90 K iSelect platform. A total of 9689 SNPs, 45 SSRs, and 3 STS makers were used in constructing linkage maps. The length of whole linkage maps was 3594.0 cM with marker density of 0.37 cM between two markers.  A total of 95 QTL were detected, 11 for days to heading, 7 for plant height, 37 for yield components and 40 for physiological traits on 47 chromosome fragments, representing the 21 chromosomes. Eighteen stable QTL were detected across five environments, Q.HD.ui-4A, Q.HD.ui-5A.1, Q.PH.ui-1A.1, Q.PH.ui-6A, Q.PH.ui-5B, Q.SL.ui-7A, Q.SL.ui-3B, Q.SL.ui-5D, Q.SN.ui-5A.1, Q.KN.ui-2B, Q.KN.ui-6D, Q.SPN.ui-4A, Q.SPN.ui-6A, Q.TKW.ui-1A.2, Q.TKW.ui-3D, Q.CTg3.ui-6B, Q.CCIg2.ui-5A.2, Q.CCIg3.ui-4D, which explained up to 40% of the phenotypic variance. 6 QTL-rich chromosome regions were found on chromosome 1A (2), 4A, 5A (2) and 6A. These QTL and linked molecular markers can be used in selecting higher grain yield in spring wheat cultivar development.