Abstract

                                An attempt was made to study variability and genetic parameter analysis in the F 3 and F 4 generation of rice genotypes. The phenotypic variance was higher than the corresponding genotypic variance for all the characters in F 3 and F 4 generation. These differences were indicating greater influence of environment for expression of the traits in F 3 generation and F 4 generations. Considering genetic parameters high genotypic coefficient of variation (GCV) value was observed for number of productive tillers per plant (25.78) and single plant yield (24.578), whereas moderate genotypic coefficient of variation value was exhibited by plant height (10.59). In the present study, all the characters studied recorded generally high heritability estimates in both the generations except panicle length and spikelet sterility in F 4 generation. High heritability with high genetic advance in percent of mean was observed for stigma exsertion percentage, plant height, number of productive tillers / plant and single plant yield indicated that these characters were under additive gene control and selection for improvement might be effective. Spikelet fertility percentage and pollen sterility percentage showed high heritability but low genetic advance (%), which indicated that non additive gene effects were involved for phenotypic expression of this character.

Key words : TGMS rice, F 3 and F 4 generation, variability, phenotypic and genotypic parameters