Genetic analysis in various genotypes of bread wheat under normal and heat-stress environments

Abiotic stresses have brought the crops to a destructive position towards yield production of crops, especially wheat. The present study was investigated to compare the relationship between normal and heat stress conditions under two different sowing dates viz. normal and late sowing dates (25th Nov and 25th Dec). The correlation coefficients varied with both sowing dates (normal and late planting). In normal planting number of grains showed a significant positive correlation with grain weight spike-1 (r = 0.618**), grain yield plant-1 (r = 0.591**), seed index (r =0 .456**), biological yield plant-1 (r = 0.540**) and harvest index (r =0 .667**). Grains spike-1 contributed significant positive correlation with grains spike-1 (r=0.094**), grain yield plant-1 (r=0.844**), biological yield plant-1 (r=0.936**), harvest index (r=0.556**), leaf area (r=0.791**), relative water content (r=0.763**), chlorophyll content (r=0.853**), cell membrane stability (r=0.828**) and stomatal conductance (r=0.292**). Grain yield plant-1 exhibited a significant positive correlation under normal planting with the number of tillers plant-1, number of spikelets spike-1, grains spike-1, and grain weight spike-1 (r=0.695**,0.207*,0.591**and 0.950**), respectively. Whereas, late planting declared grains spike-1 revelaed signficant positive correlation with grains spike-1 (r=0.094**), grain yield plant-1 (r=0.844**), biological yield plant-1 (r=0.936**), harvest index (r=0.556**), leaf area (r=0.791**),relative water content (r=0.763**), chlorophyll content (r=0.853**), cell membrane stability (r=0.828**) and stolatal conductance (r=0.292**). Under late planting, Yield showed a significant positive correlation with spike length, grains spike-1, and grain weight spike-1 (r=0.343**,0.844**, and 0.964**), respectively