Unveiling the Genetic Dynamics of Heat Stress Responses in Wheat RILs for Identifying Heat-Tolerant Genotypes

An investigation was conducted in randomized block design under timely and late sown conditions using two hundred recombinant inbred lines from a cross between WH711 and WH1021 cultivars. The heat stress conditions have detrimental effects on the performance of recombinant inbred lines (RILs), as depicted by alterations in different phenotypic traits. The grain filling duration, number of effective tillers per meter, grain yield/plot and biological yield/plot traits under non-stress conditions and number of effective tillers per meter, biological yield/plot, number of grains/spike, and 100 grain volume traits under heat stress conditions recorded moderate estimates of coefficient of variations. High heritability coupled with moderate to high genetic advance was recorded for number of effective tillers per meter, and 100 grain volume traits under both conditions. Complementary and duplicate types of interactions were observed depending on trait and environment. Several RILs were reported with presence of beneficial traits, showing negative heat susceptibility indices (HSI) values. The recombinant inbred lines 59 and 106 could be considered the most heat-tolerant recombinant inbred lines which can provide a substantial initiation for future studies and breeding endeavors aimed at creating wheat genotypes that can flourish in heat-stressed environments.