Genetic variability and heritability in advanced rice (Oryza sativa L.) strains under heterogeneous environments

Abstract

Rice (Oryza sativa L.) plays a pivotal role in global food security, feeding more than half of the world’s population. To sustain rising demands amidst climate change, population growth, and resource constraints, enhancing yield potential and trait stability in rice is imperative. This study investigates the magnitude of genetic variability, heritability, genetic advance, and correlation among 27 advanced rice genotypes across three heterogeneous environments. Using a randomized block design, phenotypic and genotypic coefficients of variation, broad-sense heritability, genetic advance as percent of mean, and correlation and path coefficient analyses were conducted. Significant differences among genotypes were observed for all measured traits, including yield. High heritability with high genetic advance was noted for productive tillers, biological yield, and fertile spikelets, indicating the predominance of additive gene effects. Path coefficient analysis revealed biological yield and spikelet fertility as the most influential contributors to yield. This study provides a statistical foundation for informed varietal selection and breeding in diverse environments to improve yield and sustainability in rice.