Detection of QTLs Associated to Some Grain Traits in Bread Wheat (Triticum aestivum L.), Using Association Mapping

This study was conducted to identify markers associated with some kernel traits in bread wheat in two separate experiments under field and laboratory. One hundred wheat genotypes were evaluated in an alpha lattice experimental design with two replications. Grain hardness¡ seed length¡ seed width and thousand kernel weights were measured. Association mapping was performed based on 96 unlinked and 22 SSR QTL linked markers¡ using structure and Tassel software. Correction for population structure was performed using genome wide SSR markers so that genotypes were divided into six sub-populations. Totally¡ 35 SSR markers linked to traits were detected; eight of them being QTL linked markers and other markers that were linked to traits¡ were used to investigate population structure. The QTLs linked markers were as follows: Chromosomes 5B¡ 5D and 6D had three QTL for grain hardness. Nine QTLs were detected on chromosomes 1A¡ 1B¡ 2A¡ 2B¡ 2D¡ 5B¡ 5D¡ 6D and 7B for kernel length¡ kernel width and thousand kernel weights. The results of this study demonstrate that association mapping is a useful approach to complement and enhance previous QTL information for marker-assisted selection in wheat.