Assessment of Genetic Variability, Heritability, Genetic Advance and Association Analysis in Elite Lines of Rice (Oryza sativa L.) in Raipur (C.G.), India

Abstract

Aims: The experiment aims to assess the genetic variability, heritability, genetic advance, and association among elite lines of rice (Oryza sativa L.) to better understand the genetic basis of key traits and inform future breeding programs. Background: Increasing productivity is the key to increasing rice production. Chhattisgarh produces a significant portion of the nation's rice and covers the most area in rice during the kharif season. The availability of diverse rice varieties plays an important role in expanding rice production across various agro-ecologies. Methodology: The current experiment was carried out at the Research cum Instructional farm of the Department of Genetics and Plant Breeding, College of Agriculture, IGKV, Raipur (C.G.), India. The experimental material comprised 57 rice genotypes (including checks), evaluated in a randomized complete block design with 2 replications, to assess 12 quantitative characters. A high magnitude of genotypic coefficient of variation and phenotypic coefficient of variation was obtained for the number of unfilled grains per panicle whereas, Grain yield per plot showed a high value of Phenotypic Coefficient of Variation (PCV) and moderate value of Genotypic Coefficient of Variation (GCV). Results: High heritability along with high genetic advance as a percentage of mean was observed for the number of unfilled grains per panicle followed by the number of filled grains per panicle, number of effective tillers per square meter, flag leaf length and hundred seed weight, suggesting more stable and less impacted by environment, controlled by additive gene action. Grain yield per plot showed a highly positive and significant correlation at both genotypic and phenotypic levels with harvest index followed by biological yield, number of filled grains per panicle and number of effective tillers per square meter. Conclusion: The result of path coefficient analysis indicated that harvest index had the maximum direct effect on grain yield per plot followed by days to maturity, biological yield, number of effective tillers per square meter, plant height, number of unfilled grains per panicle, 100 seed weight and flag leaf length. Favourable genotypes on the basis of preferred kernel length/ breadth ratio are characterized under medium slender range viz., IR18A1061, R-2322-180-1-169-1, R-RHZ-CC-162 and R- 2485-PHD-SPS-15-1. Genotypes with intermediate alkali spread values are preferred, including R-RHZ-RKC-212, R-RHZ-MI-95NS, IR18A1042, R2744-19-1, IR17A3050, R-RGY-IS-110, R-2485-PHD-SPS-15-1, IR18A1073 and R2744-118-1.