High-Density SNP Mapping and Quantitative Trait Locus Analysis of Glaucousness and Leaf Colour in Common Wheat

Glaucousness is associated with drought response and leaf colour with nutritional status and chlorophyll content. The purpose of this study was to map these traits in wheat (Triticum aestivum L. em Thell.) grown within the dry prairie region of Canada.  Glaucousness and leaf colour were measured visually in a sub-population of 100 doubled haploid lines derived from a hexaploid wheat cross between ‘Carberry’ and ‘AC Cadillac’. The population and parents were phenotyped near Swift Current, Canada under rain-fed and irrigated conditions in 2013 and rain-fed conditions in 2014. A high density map was developed using DArT® and markers from the 90,000 wheat iSelect SNP array. The map was generated using MSTMap and JoinMap v4.1 based on 324 lines.   Composite interval mapping using QTL Cartographer revealed 8 significant (LOD>3.0) QTL for glaucousness and 7 QTL for flag leaf colour. The QTL accounted for 7 to 19% of the glaucousness variation and 9 to 18% of the colour variation. Glaucousness QTL were located on chromosomes 1A, 2A, 2B, 3A, 4B, 5A, 7A, and 7B.  Colour QTL were located on chromosomes 1B, 2A, 2D, 3A, 5A, 5B, and 7D. The results demonstrate glaucousness and leaf colour are under complex genetic control in common wheat.