Abstract
Climate change plays a key role in wheat production. The objective of this study was to identify and select efficient parents and cross combinations based on general and specific combining ability under different climatic conditions. Analysis of combining ability was carried out by Line x Tester mating design by crossing 10 lines and 5 testers resulting in 50 F-1 hybrids. All of these 65 genotypes sown in the Randomized Complete Block Design (RCBD) in three replications during cropping season of 2015-16 in both normal and heat stress conditions. Significant genetic variation was observed for yield and related characters. The general combining ability (GCA) estimates revealed that parents naming SW89.5277, V-12103 and V-13248 showed excellent general combining ability for almost all of the traits study under both conditions. It was also found that the crosses i.e. V-13241 x Millat-11 for plant height, V-13248 x Millat-11 for spikelets per spike, V-13013 x Millat-11 for grains per spike, Shahkar-2013 x Chenab-2000 for thousand grain weight and Faisalabad-08 x V-12082 for grain yield per plant, exhibited good specific combining ability estimates under both conditions. The parents and crosses that exhibited excellent results in terms of GCA and SCA estimates may be exploited in improving the yield of crop and yield related characters against normal and heat stress conditions.