Gene Action and Combining Ability of Cellular Thermotolerance in Bread Wheat (Triticum aestivum L.)

摘要: Heat stress is one of the most important factors limiting growth and productivity wheat. In present study, gene action, general (GCA) specific (SCA) combining ability cellular thermotolerance were studied in a nine-parent half diallel cross bread wheat evaluated under normal (1 st sowing date) heat (late conditions. The was estimated based on cell membrane thermostability (CMS) tetrazolium chloride (TTC) reduction. Grain yield/plant (GYP), 1000-kernel weight (TKW), stem diameter (STD) tolerance index (HTI) measured. Compared with their parents, F1 hybrids significantly produced higher GYP, CMS, TTC HTI. Highly significant mean squares GCA SCA effects observed for all traits being much larger than that SCA. additive (a) non-additive (b) actions predominance actions. However, dominance genetic variance CMS greater variance. Moderate to high narrow-sense heritability obtained (0.52), (0.57) HTI (0.71). GYP correlated (r = 0.62), 0.63) 0.60). A highly positive correlation between 0.73), supporting could be used as efficient criteria selecting genotypes stress. parents P9, P1 P2 identified best combiners respectively. Six crosses promising combinations (P1 × P8 P5 P9), (P4 P9 P6) P9). Thus, inclusion these superior into breeding programs useful improvement