Genetic Architecture, Studies to Identify the Selection Criteria for Yield in Long Duration Rice Lines (Oryza sativa L.)

The current study aimed to explore the genetic variability, narrow sense heritability, genetic advance, Intra and Inter character associations, path coefficient analysis and principal factor - component analysis of yield component traits in long duration varieties of rice. The goal was to identify keynote factor for grain yield promoting, in event on exposure to long duration vegetative phase and engaged in long photosynthetic duration. High heritability and genetic advance, along with strong correlations with yield, were observed for filled grains per panicle and total grains per panicle, suggesting their suitability for direct phenotypic selection to improve these traits. Test weight showed a genuine relationship with grain yield, indicating its effectiveness for direct selection. Principal component analysis noted four components, with eigenvalues higher than 1, explaining 86.5 percent of the total variability. Among these components, the highest variability was attributed to filled grains per panicle and total grains per panicle. Filled grains per panicle is identified with positive direct effect and noted positive significant correlation for the grain yield per plant, making it an effective selection criterion for improving grain yield in long-duration rice crops.