Assessing yield stability of heat-tolerant lentil genotypes across multiple hotspot regions in Bangladesh

Terminal heat stress is a major abiotic constraint affecting lentil cultivation worldwide, presenting a significant challenge for plant breeders working to develop heat-tolerant genotypes. In this study, six heat-tolerant lentil genotypes BLX 09015, BLX 05002-3, LRIL-21-1-1-1-1, LRIL-21-1-1-1-1-6, BLX 05002-6 and a popular cultivated variety, BARI Mosur-8 (used as a check), were evaluated to identify more stable heat-tolerant genotypes across various agro-ecological zones in Bangladesh. Stability analysis was conducted based on grain yield data. The combined analysis of variance revealed significant differences among genotypes, environments, and genotype-environment interactions. Across the environment, BLX 05002-3 performed best in Barishal, BLX 05002-6 in Ishurdi, BARI Mosur-8 in the Barind region of Rajshahi, and LRIL-21-1-1-1-1-6 in Gazipur for improved yield. Among the four locations, Ishurdi proved to be the most stable for lentil cultivation, followed by Rajshahi, Barishal, and Gazipur, respectively. However, genotypes BLX 09015 and LRIL-21-1-1-1-1 showed instability in yield performance across the four environments. Overall, based on AMMI stability parameters, GGE biplots, Principal Component Analysis, Multitrait Stability Index (MTSI), and Y×WAASB biplot the genotype BLX 05002-3 was identified as the most stable across environments for yield traits and grain yield under terminal heat stress conditions.