Analysis of Agro-morphological Characters and Genetic Diversity in Some Selected Landraces of Rice During Early Drought Stress

Abstract

Abstract Drought is a major threat to rice production in many parts of the world. The red-lateritic zone of West Bengal, India, faces physiological drought each season, specifically in early growth stage due to erratic rainfall. No true-drought-tolerant variety has been developed till date due to lack of proper screening methods and undetected major Quantitative-Trait-Loci linked to drought tolerance. In this study, twenty-two landraces and check varieties were subjected to water stress at seedling stage. Root and shoot length (RL, SL), seedling-vigour-index (SVI), root fresh and dry weight (RFW, RDW), leaf rolling (LR), leaf drying (LD) were recorded. After rewatering, survivability percentage (SP), days to 50% flowering (DF), days to maturity (DM), 100 seed weight (SW), seed yield/plant (SY/P) were observed. Significant variations between the germplasms were noted. Significant positive correlation was found between SP, SW, DM, DF, RFW, SL, and SY/P whereas LD, LR were negatively correlated with SY/P. T-test between the yield of stressed and controlled conditions revealed that twelve landraces along with the positive checks did not vary significantly in SY/P. One landrace, Morogjhota outperformed the check varieties in yield. Genetic diversity analysis with 20 SSR markers divided the germplasms into two main clusters with a PIC value ranging between 0.544 – 0.907. From this study, seventeen lines were identified among which five landraces showed high Drought Resistance Index which can be used as parent material in developing climate-resilient varieties and can also be used to detect major QTLs associated with drought tolerance. Keywords: Agro-morphological characters, Drought resistance, Landrace, Rice, SSR markers