Unravelling Trait Interrelationship and Effects in Mapping Population Derived from Jaya × Goa Dhan 2 of Rice (Oryza sativa L.)

The study aimed to analyse the relationship between grain yield and its component traits in rice for identifying key contributors to yield improvement. An Augmented Randomized Complete Block Design (RCBD) was employed to evaluate 244 recombinant inbred lines (RILs) derived from the cross Jaya × Goa Dhan 2 along with ten check varieties. The experiment was conducted during the Rabi, 2022–23 at field conditions at ICAR-Central Coastal Agricultural Research Institute, Goa. Thirteen agronomic traits were recorded and subjected to correlation and path coefficient analysis to determine their direct and indirect effects on grain yield. Correlation analysis revealed significant positive associations of grain yield with straw yield (0.40), harvest index (0.56), total productive tillers (0.46), days to 50% flowering (0.34), total number of grains per panicle (0.20), number of fertile grains per panicle (0.25) and flag leaf width (0.14), whereas plant height (–0.23) and flag leaf length (–0.19) were negatively correlated. Path coefficient analysis indicated that harvest index (0.944) and straw yield (0.842) recorded the strongest positive direct effects, supported by moderate contributions from total productive tillers and number of fertile grains per panicle. The residual effect of 0.092 indicated that a portion of yield variation remained unexplained by the studied traits, suggesting the role of additional physiological and morphological factors in determining rice productivity. Overall, harvest index, straw yield and total productive tillers were identified as the most important determinants of grain yield, highlighting their potential as selection targets in rice breeding programs aimed at enhancing productivity.