Study on genetic variability, heritability and genetic advance in rice

Three groups of crosses representing high X high, high X low, and low X low general combiners were advanced to F₂ and F₃ generations to study variability, heritability and genetic advance in rice. In general, heritability showed an increasing trend from F₂ to F₃ generation but variances and genetic advances were reduced. Among the characters, panicle weight, 1000-grain weight, and number of fertile spikelets per panicle recorded high heritability coupled with moderate to high genetic advance, indicating that they were governed by additive gene action and therefore these traits of fer greater scope for further improvement through selection. Among the crosses,high x lowgca combinations exhibited high mean and variability in both F₂ and F₃ generations for all the characters, which implies that high x low combination is likely to produce higher frequency of transgressive segregates than either high x high or low X low combinations.