Phenotyping black gram genotypes under water stress condition at flowering stage for insights into genetic diversity and stress tolerance mechanisms

Climate change poses a significant threat to global food security, emphasizing the need to investigate drought stress and identify genotypes with enhanced stress tolerance. The present study evaluated 40 black gram genotypes by examining key physiological, biochemical and yield traits under water stress and stress-free conditions for resilience over two consecutive kharif seasons (2021 and 2022). Results showed that significant effects (p < 0.01) of growing seasons, treatments, and their interactions for most of traits, while genotype effects were significant (p < 0.01) across all traits. Generally, most morpho-physiological traits exhibited higher values under normal conditions, except for canopy temperature depression (CTD), total soluble sugars, and proline content, which increased under water stress. Cluster analysis grouped the genotypes into five distinct clusters. The study highlights the importance of characterizing key traits for the effective use of germplasm in crop improvement. Several drought tolerant genotypes, including IPU10-21, IPU9-26 and IPU2-43, IPU10-23, IPU10-33, IPU9-13-2 were identified based on their cumulative physiological and biochemical traits as well as yield performance. These genotypes have significant scope in breeding programs aimed at enhancing resilience and ensuring sustainable productivity under climatic change scenario.