Abstract
Heat stress causes severe loss in wheat yield at vegetative and grain filling stage in many parts of the world. To study heat
stress, 50 crosses were generated by crossing 15 parents (already screened) including 10 genotypes (as female lines viz., V13248, MISR 1, SW89.5277, Shahkar-2013, Miraj-08, AARI-11, Faisalabad-08, V-13013, V-13241 and V-12103) and 5 male
testers viz.,V-12056, Millat-11, Chenab-2000, ND643 and V-12082 following Line × Tester mating design in 2014-15.
Parameters like protein contents, moisture, starch, ash, gluten and test weight were investigated. These 15 parents along with
their 50 F1 hybrids were sown in a triplicate of randomized complete block design (RCBD) under normal and heat stressed
conditions. Analysis of variance (ANOVA) depicted highly significant differences among genotypes for all traits. The results
revealed that dominance type of gene action played a predominant role in the inheritance of all traits in this study. From parents,
based on general combining ability (GCA) effects, 3 parents, MISR1, Faisalabad-08, and V-13241 proved to be good general
combiners for protein, starch, gluten, test weight and ash in both normal and heat stress conditions. Genotype V-13248 showed
highest negative significant value for gluten and may be useful for gluten intolerant patients. Among F1 hybrids, AARI-11 ×
V-12082, V-13241 × Millat-11 and V-13013 × ND64 represented best specific combining ability (SCA) under both
environments for important quality traits like protein and moisture contents. These parents and their crosses were selected for
future improvement in ongoing breeding programmes of Pakistan.
