Mapping QTLs for some seed shape and size related traits in a population of recombinant inbred lines of bread wheat

Kernel shape and size are the most important characters related to the yield and domestication in bread wheat (Triticum aestivum L.). Understanding of genetic parameters of such important traits and its utilization is very important in breeding programs for this strategic crop. The aim of the present study was to identify quantitative trait loci (QTLs) corresponding to the kernel shape and size characteristics i.e. kernel weight, kernel length, kernel width, horizontal area proportion, sphericity, vertical perimeter, projection area, section area, and kernel volume within a mapping population of 118 recombinant inbred lines (RILs) of bread wheat resulting from a cross between an Iranian landrace, Tabassi, and a European wheat variety, Taifun. In total, nineteen QTLs were identified on chromosomes 1A, 2A, 2D, 3B, 4A, 4D, 5A, 5B, 5D, 6A, 7A and 7B. Genome A, B, and D were covered 53%, 26%, and 21% of the QTLs respectively. The highest number of QTL (5) and phenotypic value (42.3%), were respectively obtained for kernel length and kernel sphericity. Among the QTL regions identified, one region on chromosome 2A corresponding kernel length and volume and one region on chromosome 5D controlling sphericity and projection area are referred to as pleiotropic regions. The results of this study, in agreement with other studies, are recommended in marker-assisted selection (MAS) for grain shape and size traits in bread wheat breeding programs.