Trait Based Selection of Elite Wheat Genotypes under Irrigated, Heat Stress, and Heat Drought Conditions

Abstract

Environmental factors affects yield and yield-attributing parameters of wheat. To explore direct and indirect association and to identify the most appropriate trait for trait based selection of elite wheat genotypes under irrigated, heat stress and heat drought conditions, correlation, path and principal component analysis were performed. The field experiment was conducted using serpentine alpha lattice design at the agronomy farm of the Institute of Agriculture and Animal Science (IAAS), Paklihawa campus, Nepal that comprised of twenty elite wheat genotypes. The grain yield of wheat was found to have significant negative association with days to heading (DTH) and days to booting (DTB) under all tested conditions. Plant height (Ph) was found to have a significant negative association with grain yield of wheat under irrigated conditions while significant positive association was observed across heat stress and heat drought conditions (p≤0.05). DTB, DTH, and Ph had a direct influence on the yield across all tested conditions. For the breeding program, dwarf genotypes that are earlier in booting and heading should be promoted under irrigated conditions whereas the taller genotypes that are earlier in booting and heading should be promoted under heat stress and heat drought conditions. Based on selected traits, BL 4919 and NL 1350 were selected as high yielding genotypes under irrigated condition, NL 1369 and NL 1417 under heat stress condition and NL 1350 and Bhrikuti under the heat drought condition. These genotypes should be promoted in the varietal improvement program of Nepal to release as a potential climate resilient variety.