Assessment of Genetic Variability, Heritability and Genetic Advance in Relation to Yield and Quality Traits among Advanced Breeding Lines Derived from Multiple Cross of Rice (Oryza sativa L.)

Abstract

Introduction: Rice (Oryza sativa L.) (2n=24) is a major cereal crop that belongs to the Poaceae family and the Oryzoidea subfamily. It is known as the "Global Grain" because it is a staple food in over 100 countries. Aim: The present study assess the extent of genetic variability, heritability and genetic advance among yield and quality traits in advanced rice breeding lines, with the objective of identifying effective selection criteria for yield and quality improvement. Study Design: Randomized block design. Place and Duration of Study: Conducted at the Institute of Rice Research, ARI, Rajendranagar, Hyderabad, Telangana, India, during the Rabi season of 2023. Methodology: The study encompassed 30 advanced rice breeding lines derived from a multiple cross [(IET 23993 x NLR 34449 // BPT 5204) x (NDLR 7 x Tetep // BPT 5204)]) along with three check varieties with 2 replications were evaluated for 15 yield and quality traits. The experimental material was grown under standard agronomic practices and data were recorded on traits such as number of productive tillers per plant, number of grains per panicle, 1000-grain weight, plot yield (kg/ha) and head rice recovery (%). Statistical analyses, including estimation of variance, genotypic and phenotypic coefficients of variation (GCV and PCV), heritability and genetic advance, were conducted to assess genetic parameters influencing trait expression.Statistical analysis was conducted using INDOSTAT software for the analysis of variance for variability, heritability and genetic advance. Results: Analysis of variance revealed highly significant differences (P < 0.01) among genotypes for all traits, indicating substantial genetic variability. High GCV and PCV values were recorded for number of grains per panicle (24.40), (24.56), plot yield (23.92), (22.27) and number of productive tillers per plant (22.06), (18.98) suggesting these traits are under strong genetic control and amenable to direct selection. Traits such as number of grains per panicle, productive tillers per plant, 1000-grain weight, plot yield, and head rice recovery exhibited high heritability coupled with high genetic advance as a percentage of mean, indicating the prevalence of additive gene action. Conclusion: The study demonstrates that several key yield and quality traits are governed by additive gene effects, making them ideal targets for direct selection in rice breeding programs aimed at enhancing productivity and grain quality. These findings provide valuable insight for genetic improvement in advanced rice breeding lines.