QTL analysis of some physiological and biochemical traits associated with grain yield in wheat under terminal heat stress

To identify the genomic regionswith main, epistatic, and QTL×environment (Q×E) interaction effects for some of the physiological and biochemical traits of wheat, an experiment was conductedat Research Farm of Agricultural and Natural Resources Research Center of Sistan, Iran, in 2015-16 growing season. The experiment was carried outusing two alpha lattice designs with two replications under non-stress and terminal heat stress conditions.Plant materials were 167 recombinant inbred lines andtheir parents (‘SeriM82’and ‘Babax’) andsix traits including grain yield (GY), proline content(PRO), water soluble carbohydrates (WSC), maximum efficiency of photosystem II (Fv/Fm), cytoplasmic membrane stability (CMS) and chlorophyll content (CHL) were measured. QTL analysis was conducted by Mixed-Model basedcomposite interval mapping (MCIM) method. There were significant differences among the genotypes for all studied traits and transgressive segregations in both directions were also observed. Using mixed linear model,a total of 23 main-effect QTLs were detected. The Q×E interaction was significant in five main-effect QTLs and two epistatic QTLs were also detectedfor studied traits. The most of mapped QTLsappear to be quite stable. Therefore, can be used in marker-assisted selection (MAS) in order to produce high-performance and heat tolerant wheat genotypes.