Genetic Variability and Cause-Effect Relationship in Aromatic Rice

Twenty diverse rice genotypes, mostly aromatic landraces, were grown during warm wet season of 2022 to analyse the genetic variability, correlation and path coefficients for sixteen agro-morphological characters. The results of genotypic and phenotypic coefficients of variability, heritability, and genetic advance indicated that improvement through selection for flag leaf angle, panicle exertion, secondary branches per panicle, test weight, spikelet number, and number of filled grains would be effective. Correlation coefficients of grain yield with flag leaf area, spikelet fertility percentage, test weight and harvest index were positive and significant, while with flag leaf angle it was negative and significant indicating the importance of these characters on grain yield. Path analysis revealed that selection for larger flag leaf area, greater test weight and narrow flag leaf angle, reduced plant height and early flowering would increase grain yield. However, restrictions are required to be imposed on panicle number, panicle length and filled grain, so that a balance between morphological architecture and physiological rhythm is maintained to optimize source-sink relationship.