Genetic variability and correlation of some morphometric traits with grain yield in bold grained rice (Oryza sativa L.) gene pool of Barak valley

Physically hard working people prefer bold grained rice with good taste and qualities. But most of the modern high yielding varieties are medium and fine grained. The present experiment was conducted on 47 bold grained rice genotypes with two locally recommended high yielding check varieties namely Ranjit and Monohar Sali of Barak Valley, Assam to assess the genetic variability, correlation and coheritability for eight morphophysiological characters. The characters were days to 50% flowering, plant height, flag leaf length, flag leaf breadth, effective branch tillers per hill, panicle length, sterility percentage and grain yield per hill. Very small difference between GCV and PCV was observed for the characters like days to 50% flowering and flag leaf breadth. Wide difference between GCV and PCV was observed for the characters like plant height, flag leaf length, effective branch tillers per hill, panicle length, sterility percentage and yield per plant. In the present investigation, high heritability associated with high genetic advance was found in the characters grain yield per hill and sterility percentage. These characters were predominantly governed by additive gene action. High heritability along with moderate genetic advance was observed in the character plant height. Moderate heritability associated with moderate genetic advance was recorded for the characters effective branch tillers per hill, flag leaf length and flag leaf breadth. Lastly, high heritability with low genetic advance was recorded for the character days to 50% flowering. This indicated that these characters were mostly governed by nonadditive gene action (dominance and epistasis). The genotypic correlation coefficient was found to be higher than the corresponding phenotypic correlation coefficient. This indicates a strong inherent association among grain yield per plant and other morpho-physiological characters. The characters sterility percentage, effective branch tiller per hill and panicle length showed significant positive genotypic correlation with grain yield per hill. Sterility percentage, effective branch tiller per hill and panicle length had high coheritability with grain yield suggesting that selection for these characters would improve grain yield.