Morphological characterization and expression profiling for study of drought responsive genes in rice oryza sativa l

Abstract

The current study entitled Morphological characterization and expression profiling for study of drought responsive genes in Rice (Oryza sativa L.) was conducted to investigates the response of various rice genotypes to water stress, revealing critical insights for improving drought tolerance, using 58 genotypes for twenty six traits (morphological, physiological and biochemical) in randomized complete block design in three replications at Crop Research Centre, SVPUAT, Meerut during Kharif 2022 and 2023. Varieties like Nagina 22, Jaya, Manohar, and Ratna demonstrated superior stress tolerance, maintaining higher yield and photosynthetic efficiency. These varieties are considered promising genotypes for cultivation in drought-prone regions due to their enhanced physiological mechanisms for coping with water deficit stress traits like Relative Water Content (RWC) and SPAD values, were identified as reliable indicators of drought tolerance. Tolerant varieties showed smaller reduction in these metrics, maintaining better hydration and chlorophyll content. Additionally, canopy temperature and proline accumulation were important indicators of stress tolerance, with proline levels being significantly higher in stress-resilient varieties. The antioxidant enzyme peroxidase, particularly in the variety Pusa Basmati 1, also played a crucial role in mitigating oxidative stress, further enhancing the ability of some genotypes to withstand of some traits water deficits. Genetic variability and the correlations studies among rice traits under stress conditions, highlighted the potential for breeding improvement. Traits with high genotypic coefficient of variation (GCV), like membrane stability, proline content and yield-related parameters exhibited substantial variability and responsiveness to selection. These traits represent key targets for improving drought tolerance and yield through breeding programs. In contrast, traits with low GCV, including days to maturity and plant height, may require advanced breeding techniques to