Grain Yield Stability of New Bread Wheat Genotypes (Triticum aestivum L.) under Normal and Heat Stress Conditions

FORTY-TWO bread wheat genotypes (Triticum aestivum L.) were evaluated in eight environments in Egypt: two locations and two planting dates during the two 2016-2017 and 2017-2018 growing seasons. The objectives of this study were to estimate grain yield, number of spikes plant^-1, 1000-kernel weight and plant height of these 42 bread wheat genotypes under different environments and to determine their stabilities. Combined analysis shows that most mean squares was attributed to environmental effects, indicating that environments were diverse, with large differences among environmental means causing most of variation in grain yield and the other studied traits. Mean squares due to genotypes were highly significant for grain yield and the other traits, indicating that the existence of inherent genetic variability and point to the possibility of selecting a stable wheat genotypes .Mean squares due to Geno x Env were highly significant for all studied traits, indicating that there are substantial differences in genotypic response across environments. Mean squares due to genotypes were significant for all studied traits. Mean squares of E+ (GxE) were highly significant for all studied traits. Linear components of genotype-environment interaction were significant or highly significant for all studied traits. The highest-yielding genotypes overall environment were G21 (360.25g), G15 (349.52g) and G13 (303.96g) and did not differ significantly from check variety Giza-168 (341.76g). Six genotypes namely, G13, G21, Giza-168 Shand-1, misr-1 and Sahel-1 showed better general adaptability across environments.