Studies of Genetic Variability for Grain Yield and Yield Contributing Traits in Recombinant Inbred Lines of Rice (Oryza sativa L.)

Genetic variation in recombinant inbred lines (RILs) provides opportunities to identify breeding materials for improving quantitative traits. A population of 122 F₁₇ rice RILs derived from Danteshwari × Dagad Deshi was evaluated during the 2022 kharif season at Raipur, India, in a randomised complete block design with two replications under non-stress field conditions. Seventeen grain-yield and yield-associated traits were summarised using their observed ranges, means, genotypic coefficients of variation (GCV) and phenotypic coefficients of variation (PCV). Phenotypic variation exceeded the corresponding genotypic variation for every trait in the available summary. The largest GCV estimates occurred for harvest index (25.94%), unfilled grains per panicle (25.37%), grain yield (23.31%), flag-leaf length (22.80%) and filled grains per panicle (21.16%). Using the stated GCV and PCV values, the implied broad-sense heritability was 95.15% for days to 50% flowering, 88.69% for flag-leaf length and 87.90% for filled grains per panicle. Grain yield had an average of 3.70 t ha⁻¹, a GCV of 23.31% and an implied heritability of 69.11%. These descriptive results identify traits that may be useful for selection within the population. However, genotype effects and predicted gains depend on the statistical scale and variance components used; independent validation of the variance analyses is necessary for quantitative selection decisions.