High temperature conditions negatively affect maize plants development leading to loss in grain yield. Therefore, this study was conducted to evaluate response of high temperature on the basis of yield performance and its components of six maize genotypes in order to find tolerant genotypes under high temperature conditions. The study was carried out in a randomized complete block design (RCBD) with three repetitions, to assess, Plant height, green leaves no., leaf length, leaf width, leaf area, dry leaves no., ear distance from earth, ear length, ear diameter, ear rows, ear weight, ear grains weight, weight of 100 grains and grain yield/plant. The findings indicated that there was significant genetic variation among the studied genotypes. According to Pearson correlation coefficient, heatmap and principal component analysis, the leaf width, leaf area, ear length, ear diameter, ear rows, ear weight and ear grain weight had positive correlation with grain yield. Consequently, these traits can be chosen as a best trait to improve maize grain yield under heat stress conditions. In addition, genotypes G-70, G-71 and G-76 were found to be tolerant to heat stress due to their high values traits that positive correlated to grain yield potential as approved by cluster analysis that showed that these genotypes cluster together in group (B). Considering that these genotypes could be useful in developing heat tolerant varieties as a parental material in breeding programs.

Maize (Zea mays L.), high temperature, yield traits, Pearson correlation, heatmap analysis, PCA, phylogenetic tree

Genotypes G-70, G-71 and G-76 exhibited superior performance in grain yield and its components, indicating that theses genotypes may share genetic factors that improve yield production under high temperature conditions, so these genotypes can be used as a parental source of high temperature tolerance in maize breeding programs. In addition, leaf area, leaf width, ear rows, ear weight, ear grains weight, weight of 100 grains and grain yield were considered main varied traits which may be used as a selection criterion to enhance maize plants under high temperature conditions.

Saleh A. Abuzaid, Galal A.R. El-Sherbeny, Abdelsabour G.A. Khaled, Ismail M.A. Bedawy and Haitham M.A. Elsayed (2025). Performance of Six Maize Genotypes under High Temperature based on Grain Yield Traits. International Journal of Theoretical & Applied Sciences, 17(1): 32–40.