Genetic variability and yield trait associations in F2 populations of traditional rice (Oryza sativa L.) varieties

Analyzing genetic variability and trait correlations is essential for designing effective breeding programs and improving crop characteristics. This study aimed to estimate variability parameters, heritability, genetic advance, skewness, kurtosis, associations, and path coefficients for 13 traits in the F2 population derived from the crosses CO 54 x IC 378202 and CO 54 x IC 467496. The cross CO 54 x IC 378202 cross exhibited notable panicle weight with high Genotypic Coefficients of Variation (GCV) (35.94) and Phenotypic Coefficients of Variation (PCV) (36.40), elevated Heritability (H2) (97.48), significant Genetic Advance as a Percentage of Mean (GAM) (73.10), and positive skewness (0.52). Similarly, the CO 54 x IC 467496 cross demonstrated exceptional total tillers per plant, characterized by high Genotypic Coefficients of Variation (33.63) and Phenotypic Coefficients of Variation (35.25), substantial Heritability (90.99), notable Genetic Advance as a Percentage of Mean (66.08), and pronounced positive skewness (0.67). In the CO 54 x IC 378202 cross, panicle weight, displayed significant positive correlations (0.641) and direct positive effects (0.2370) on grain yield per plant. Similarly, the CO 54 x IC 467496 cross grains per panicle exhibited strong positive correlations (0.383) and direct effects (0.5360) on grain yield. These findings underscore the significance of panicle weight and grain number per panicle, key determinants of grain yield, as prime targets for selection in rice breeding programs. The observed predominance of additive gene action for these traits suggests their amenability to improvement through pure line selection. By prioritizing these traits, breeders can develop high-yielding rice cultivars, thereby enhancing agricultural productivity and contributing to global food security endeavors.