Inheritance of ratooning ability in a cross ir 19657 x ir 56 of rice

The parental, F₂, F₃ and F₄ generations of a rice cross, IR 19657-34-2-2-3-3 A x IR 56, were evaluated for ratooning ability. Additive and dominant gene effects were significant. The dominance of genes for lower parental value predominantly controlled the inheritance of ratooning ability in this cross. Broad-sense heritability estimate was moderate, whereas narrow sense heritability values were low in F₂ and F₃, indicating the contribution of nonadditive gene action to the expression of this character. Selection schemes utilizing additive and nonadditive gene actions should, therefore, be adopted for the improvement of rice ratooning ability.