Identification and characterization of drought-tolerant rice (Oryza sativa L.) genotypes using morpho-physiological and biochemical traits

Drought stress is a major constraint and the primary cause of low rice production in rainfed ecosystems. The results obtained from the study revealed the existence of significant variation among all the genotypes studied for different physiological and biochemical parameters. Genotypic and phenotypic coefficients of variation were wide-ranging, with traits like PC and grain yield showing higher values. Moderate to high heritability and genetic advance percentage of mean suggested the feasibility of selection for improved traits. The mean performance of genotypes revealed specific genotypes, such as Gin, excelling in root-related traits and filled grains per panicle. Leaf rolling and drying responses varied among genotypes, providing insights into drought tolerance. Positive correlations between grain yield and traits like flag leaf length, panicle length, and spikelet fertility were observed. Path coefficient analysis identified direct relationships between yield and traits such as flag leaf breadth, chlorophyll content, and root volume. So, this study provides a comprehensive understanding of genetic variability and trait relationships among rice genotypes, offering valuable insights for the selection of resilient varieties with improved root, shoot, and yield traits, particularly crucial for addressing drought stress.