Scouting rice (Oryza sativa L.) landraces for moisture stress tolerance using morphometric diversity analysis

Climate-change is a major threat to sustainable agriculture. Rice is one of the staple food grains that sustain 2/3rd of global population. Therefore, developing climate-resilient rice genotypes to combat moisture stress and other climate change factors are most important to address the challenges posed by climate change. The vast availability of genetic variance among the rice genotypes for different traits favours the selection of desirable donor parents. A field investigation was carried out to characterize 21 traditional rice landraces under induced moisture stress in 2 environments including induced moisture stress (S) and non-stress (NS). The response to the varied level of environments was observed in terms of biometric and yield parameters followed by multivariate analysis and variability analysis. The study revealed higher phenotypic-coefficient of variation (PCV) and genotypic-coefficient of variation (GCV) for plant height and single plant yield in both environments. High heritability was also recorded in the moisture stressed environment for plant height (98.63 %), single plant yield (98.19 %) and productive tillers (95.12 %), whereas under NS, the heritability is more for single plant yield only (99.56 %). The genotypes formed nine clusters under the S environment, based on the Euclidean distance, of which the three CMS lines segregated in cluster III distinctly. The principal component analysis exhibited three principal components with a cumulative variance of 86.13 % and 86.40 % in the NS and S environments respectively. The traits such as days to 50 % flowering, panicle height, panicle length, grains per panicle, productive tillers, thousand-grain weight and single plant yield were the positive contributors. Spikelet fertility (%) and harvest index were positively correlated with seed yield per plant. Path-coefficient analysis was significant for grain yield, harvest index, spikelet fertility, pollen fertility and plant height and positively influenced by productive tillers plant-1. The study concluded the prospect of using Mattaikar, Rajalakshmi, Mallikar and Kuliyadichan as potential donors for developing upland rice with moisture stress resilience.