Genetic Variability and Correlation Analysis for Yield Attributing Traits in Rice (Oryza sativa L.)
Ajmeera Akhila *
Department of Genetics and Plant Breeding, College of Agriculture, PJTAU Hyderabad, India.
L.Krishna
Regional Agricultural Research Station, PJTAU, Warangal, Telangana, India.
C.V.Sameer kumar
Department of Genetics and Plant Breeding, Institute of Biotechnology, PJTAU, Hyderabad, India.
T.Kiranbabu
Institute of Rice Research, ARI, Rajendranagar, Hyderabad, India.
*Author to whom correspondence should be addressed.
Abstract
Aim: To evaluate genetic variability, heritability, genetic advance, and correlation among yield and yield-attributing traits in rice genotypes to identify effective selection criteria for yield improvement.
Study Design: Augmented block design.
Place and Duration of Study: Institute of Rice Research, ARI, Rajendranagar, Hyderabad, Telangana, India, during the Kharif season of 2024.
Methodology: The study involved 100 rice genotypes and five checks, sown in a nursery bed and transplanted after 25 days with a spacing of 30 cm between rows and 15 cm between plants. Ten agronomic and yield-related traits were evaluated: days to 50% flowering, plant height, panicle length, number of productive tillers per plant, 1000-grain weight, number of grains per panicle, grain yield per plant, kernel length, kernel breadth, and kernel length-to-breadth (L/B) ratio. Observations were recorded from five randomly selected plants per genotype. Statistical analysis was conducted using INDOSTAT software to assess variance, heritability, genetic advance, and phenotypic correlations.
Results: Analysis of variance revealed significant variation (P < 0.01) among genotypes for all traits. High heritability (>80%) was observed for days to 50% flowering (86.47%), plant height (93.90%), number of productive tillers per plant (85.24%), 1000-grain weight (94.68%), number of grains per panicle (97.34%), grain yield per plant (90.59%), kernel length (97.73%), kernel breadth (96.14%), and L/B ratio (96.07%), with panicle length showing moderate heritability (73.99%). High genetic advance as a percentage of the mean was recorded for plant height (24.28%), number of productive tillers per plant (32.77%), 1000-grain weight (45.09%), number of grains per panicle (63.42%), grain yield per plant (42.80%), kernel length (22.59%), and kernel breadth (24.02%). Grain yield per plant showed a significant positive phenotypic correlation with the number of grains per panicle (r = 0.1155, P < 0.01) and non-significant positive associations with plant height (r = 0.1116), panicle length (r = 0.0635), number of productive tillers per plant (r = 0.1540), 1000-grain weight (r = 0.1155), kernel length (r = 0.0757), and kernel breadth (r = 0.0921).
Conclusion: ANOVA confirmed significant genetic variation among 100 rice genotypes for all traits, supporting selection. Plant height, productive tillers, 1000-grain weight, grain number per panicle, grain yield, and kernel dimensions showed high heritability (>80%) and genetic advance (22.59–63.42%), indicating additive genetic control ideal for direct selection Days to 50% flowering, panicle length, and kernel length-to-breadth ratio had high heritability but moderate genetic advance, suggesting non-additive and environmental effects. Positive correlations with grain yield support indirect selection (Vennelea et al.2021). Variability among traits is useful for further selection in breeding programme.
Keywords: Correlation, genetic advance, heritability, improvement, selection