Genotype x environment interaction and selection parameters for high yielding wheat genotypes under irrigated and heat stress environment

Introduction: Wheat is a significant contributor to the food and nutritional security of the world. Due to climatic constraints and heat stress condition, the potentiality of wheat to eradicate existing hunger and malnutrition has been severely limited all around the world. Materials and Methods: To evaluate the performance and stability of elite wheat genotype under irrigated and heat stress environment, a field experiment was conducted during the wheat growing season of 2020, 2021 and 2022 under irrigated and heat stress environment that altogether created six distinct wheat growing environments. Results: The combined ANOVA revealed that all quantitative traits studied were significantly influenced by heat stress environments (p < 0.01). Which Won Where (WWW) model revealed, Bhairahawa lines (BL) 4407, Nepal lines (NL) 1384 and NL 1346 performed best under irrigated environments of 2020, 2021 and 2022 while BL 4407, NL 1384 and NL 1381 performed best under heat stress environment of 2020, 2021 and 2022. WWW model showed, NL 1369, NL 1386 and NL 1376 as the most stable genotypes across irrigated and heat stress environment. The phenotypic correlation, path analysis, network diagram, cluster analysis and cluster based principal component analysis analysis revealed traits, days to booting (DTB), plant height (Ph), spike length (SL), ten spike weight (TSW) and thousand kernel weight (TKW) are most closely associated with grain yield of wheat. Conclusion: High yielding genotypes should be selected based on earliness in DTB, longer Ph, SL and higher TSW and TKW under both environments. Breeding for taller genotypes should specifically be focused to obtain high yielding genotypes under heat stress environments.