Mapping Quantitative Trait Loci Associated with Yield and its Related Traits in Sorghum bicolor

YIELD and its related traits; heading date, hundred kernel weight and kernels number as well as harvest index and biological yield are complex traits that require the concerted action of many genes and are affected by environmental cues. To genetically dissect those traits, 140 recombinant inbred lines (RILs) genotyped with 120 DArT and SSR markers were grown under field conditions in the two consecutive growing seasons 2015/2016 and 2016/2017 in Sohag, Egypt. A part from KN and HI, our results did show significant interaction between genotypes and the growing seasons(GxS). The observed GxS was reflected by an interaction between the significant quantitative trait loci (QTL) and the growing seasons (QTLxS). In total, we report 13 significant QTL associated with HD, KW, SN, HI, and YLD, of which four QTL showed conditional neutrality as they were significant only in the second season. We observed significant negative correlation between HD and SN, HKW and YLD suggesting that selecting for early heading RILs with long grain filling period would increase the total yield, an observation that could be genetically dissected by the QTL cluster on LG-6. The associated markers mapped here can be used in breeding programs to select for favorable adaptive mechanisms, which is very crucial to meet the food requirement of an increasing human population.