QTL mapping of some important agronomic characteristics in wheat (Triticum aestivum L.)

This research was conducted to genetically dissect the quantitative trait loci (QTLs) for spike related and other agronomic traits, and to understand their mode of inheritance in bread wheat during the years of 2009-2011.A genetic linkage map was constructed based on recombinant inbred lines (RILs) derived from cross between the Turkish cultivar Gerek and Moroccon cultivar Arrehane by using DArT markers anchored with SSR markers. This map consisted of 54 linkage groups belonging to twenty one bread wheat chromosomes, spanning to a total of 935.629 cM. Total number of markers mapped varied from 5 to 87 depending on the chromosomes. Seventy seven DArT markers with unpublished chromosomal locations were mapped on different chromosomes, whereas 23 DArT markers were mapped on different chromosomes instead of their published chromosomal locations. Interval mapping was conducted to identify QTLs for agronomic and spike related traits by using four different environments/locations. The QTL analysis led to the detection of 120 QTLs. Several important and novel genomic regions for spike morphology were detected. In addition, some of the QTLs showed pleiotropic effects for different quality traits. Stable QTL clusters influencing the 1000 grain weight, spike length, number of spikelets per spike, number of grains per spike, grain weight per spike, spike compactness and flowering time were identified on chromosomes 1A, 1B, 2B, 3D and 6B. It was concluded that DNA markers might provide an opportunity for increasing the frequency of desirable alleles for spike related traits through marker assisted selection.