Identification of a Maturity QTL That Coincides with a Heading Date Locus on 7D in a DH Population of RL4452/AC Domain

The number of days to maturity or maturity date (Mat) is a quantitative trait and an important determinant of a cultivar’s suitability to a specific growing region. A doubled haploid (DH) population of 183 progeny derived from a cross between Canadian spring wheats RL4452/AC Domain was screened for QTL with 12,252 SNP markers from a 90K Infinium iSelect Custom Beadchip. A significant Mat QTL was mapped to a region on 7DS that also coincided with a heading date (Hd) and a falling number (FN) QTL. Markers flanking the Mat QTL interval on 7DS are ~12 cM apart, and this region is orthologous to a ~3 mb region on chromosome 1 of Brachypodium distachyon, and to chromosome 6 of rice. Efforts to saturate this region on 7DS in order to identify and clone underlying genes that are related to maturity are ongoing. These involve (a) identifying SNPs from an orthologous region of the diploid A. tauschii D genome, and (b) utilizing varietal SNPs via an exome capture strategy that involves screening bi- parental bulks for SNPs that correspond to the region of interest.