Combining Ability Analysis for Morpho-Physiological Traits and Grain Yield under Heat Stress Condition in Durum Wheat (Triticum durum Desf.)

Combining ability analysis for morph-physiological and grain yield traits was performed using ten selected parents in half diallel to develop forty five crosses were tested during Rabi 2016-17. Across the environments mean squares due to GCA × E and SCA × E were significant for grain filling period, flag leaf length, flag leafwidth, flag leaf area, peduncle length, total number of tillers plant-1, number of productive tillersplant-1, spike length, number of spikelet’s spike-1, spike weight productive tillers-1, grain weightspike-1, biological yield plant-1, economic yield plant-1, harvest index, protein content, prolinecontent, heat injury index and leaf canopy temperature. In addition to above traits, mean square due to GCA × E was also significant for days to 50 % flowering, days to maturity and test weightrevealed influence of environment on GCA. The s2 SCA was considerably higher than theircorresponding s2 GCA for all the characters in all the three environments except for plant height inE1 and E3, which indicated preponderance of non-additive gene action in the inheritance of thesetraits except for plant height in E1 and E3. The estimates of general combining ability effects indicated that parents NIDW-295, and HI 8498 were good general combiners for grain yield plant-1 and most of components along with heat tolerance characters. The SCA effects for grain yield plant-1 were significantly positive for 16 crosses in pool. Crosses PDW-233 × PDW-314, HI-8737 × HI-8498, PDW-274× PDW-291, NIDW-295 × PDW-274 and Raj-1555 × PDW-274 in pooled had maximum SCA. All these crosses were also having significant SCA effects for one or more components and heat tolerant characters indicate their genetic worth for these characters in respective environments.