Exploring the Interplay between Drought Resilience and Yield in Maize Hybrids for Drought-Prone Regions

This study explores the selection of maize inbreds and their subsequent hybridization, followed by the evaluation of the resulting hybrids across multi-environment trials under irrigated and non-irrigated conditions. Variance decomposition analysis revealed that environmental and trial-specific factors contributed significantly to yield variation, with 75.66% of the total variance under non-irrigated conditions attributed to trial management (Trial[Env]). Genotype accounted for 11.36%, and genotype-by-trial interactions explained 8.43%. Based on Drought Resilience Index (DRI) values, promising inbreds such as Ant-69 and Ant-24,702 were selected for hybrid development. Hybrid H3, developed from inbreds Ant-69 and Ant-24,702, exhibited strong performance across environments, consistently ranking within the top three for yield and stability. Its slow senescence, resulting in an extended grain-filling period, contributed significantly to its superior yield stability even under water-deficient conditions. Using BLUPs, hybrid performance was evaluated, with H3 demonstrating high yield stability across both irrigated and non-irrigated trials. The hybrids like C2 and H4 were highly responsive to favorable (irrigated) environments, H3 maintained greater stability across varying environments. The WAASBY index ranked H3, along with hybrid C1, as the top-performing genotypes, combining both high yield and stability. AMMI and GGE biplot analyses further confirmed H3's broad adaptability across multiple environments. These findings emphasize the significance of selecting superior inbreds, such as Ant-69 and Ant-24,702, to create hybrids that are capable of performing well under diverse environmental conditions. This research highlights the essential role of inbred selection in developing high-performing hybrids like H3, which show both yield stability and drought resilience across varying environmental conditions. The inclusion of non-irrigated trials as non-favorable environments was crucial for identifying hybrids with stay-green traits, such as extended grain-filling periods, that contribute to improved yield stability under drought. These findings emphasize the importance of evaluating hybrids across contrasting environments to develop cultivars optimized for both productivity and stability in drought-prone regions.