Genetic variability studies in F5 generation under direct seeded condition in rice (Oryza sativa L.)

The present study was conducted with the objectives to estimate genetic variability for different characters, to estimate heritability and genetic advance and to identify promising genotypes suited for direct seeded condition in rice. The study has been carried out on F5 families consist twenty-six families from thirteen crosses along with four checks were evaluated in two replication. Analysis of variance indicated that the mean square due to between family were highly significant for all characters under study, which revealed the presence of significant genetic variability between the families. Intra class correlation lead the interference that differences between individual within family is large and each family differentiated distinctly from the other at lower level in F5 generation. High GCV and PCV was recorded for gain yield plant-1 and moderate for others. High heritability was recorded for days to 50% flowering, days to maturity, number of panicles plant-1, number of spikelets panicle-1, plant height, number of filled grains panicle-1, 1000 grain weight, grain yield plant-1 and moderate for others. Genetic advance as percentage of mean were high for grain yield plant-1, number of filled grains panicle-1, number of spikelets panicle-1, 1000 grain weight, days to 50% flowering, number of panicles plant-1 and moderate for other characters. Grain yield plant-1 was the only character which recorded high GCV, PCV, heritability and genetic advance as influenced by additive gene action selection would be effective. Hence, seven families from twenty-six families derived from thirteen crosses exhibiting superiority over check for grain yield plant-1 were identified for further generations before forwarding to yield trials.