Selection of heat stress tolerant wheat genotypes for desert environments.

High temperature is a critical abiotic stress that severely impacts agricultural productivity, especially in semi-arid and arid regions. This study assesses the phenotypic performance and genetic diversity of twenty advanced wheat genotypes and checks under the field conditions of heat stress for two years. Heat stress led to significant reductions in grain yield and related traits, with an average yield decline of 53.8%. Path analysis revealed a negative impact of heading date on grain yield under stress conditions. Stress indices indicated strong heat tolerance in the genotype YR × Ksu110-240, which showed only a 10.4% reduction in grain yield, whereas DHH3-26 exhibited high sensitivity with a 53.6% reduction. Genetic diversity analysis using 30 Simple Sequence Repeat (SSR) polymorphic markers identified significant marker-trait associations, particularly Xgwm 285 and Xgwm 577, which were strongly linked to heat tolerance related traits. These markers provide valuable tools for marker-assisted selection (MAS), facilitating the breeding of heat-resilient wheat varieties. This study highlights the significance of combining molecular markers with phenotypic assessments to improve wheat adaptation to challenging environmental conditions. The wide genetic diversity offers opportunities for introducing novel alleles into breeding programs, which will be critical for developing wheat varieties that can sustain productivity under increasingly variable and extreme environmental conditions. By using the genetic and phenotypic diversities, breeders can target specific traits and markers to develop heat-resilient wheat varieties, ensuring food security in regions threatened by rising global temperatures.