Correlation and Path Analysis for Yield and Yield Attributing Traits in Hybrid Rice (Oryza sativa L.)

Abstract

Background: Yield improvement in hybrid rice depends on identifying component traits that are reliably associated with productivity. Aims: This study aimed to determine the nature and magnitude of genotypic associations and to assess the direct and indirect effects of yield-attributing traits on single-plant yield in rice. Study Design: The experimental material comprised 39 F₁ hybrids, three CMS lines (evaluated through their respective maintainer lines), 13 restorer lines, and four checks. The hybrids were developed during Kharif 2025 using a Line × Tester mating design and evaluated in a Randomised Block Design with three replications. Place and Duration of Study: The hybrids were developed during Kharif 2025 and evaluated during Rabi 2025–2026 at the experimental farm of ICAR–Indian Institute of Rice Research, Hyderabad. Methodology: Observations were recorded for eight traits: days to 50% flowering, plant height (cm), number of productive tillers, panicle length (cm), number of filled grains per panicle, spikelet fertility (%), thousand-grain weight (g), and single-plant yield (g). Results: Among the traits studied, the number of productive tillers exhibited the highest positive correlation with single-plant yield (r = 0.72, P < 0.01), followed by plant height (r = 0.45, P < 0.01), panicle length (r = 0.34, P < 0.01), and days to 50% flowering (r = 0.29, P < 0.05). Path coefficient analysis revealed positive direct effects on single-plant yield through the number of productive tillers (0.66987), panicle length (0.14114), number of filled grains per panicle (0.13347), and plant height (0.09584), indicating their contribution to yield improvement. Conclusion: Therefore, prioritising the number of productive tillers, panicle length, and number of filled grains per panicle as key selection criteria could facilitate the development of high-yielding hybrid rice cultivars and contribute to sustainable improvements in rice productivity.