Genetic variability for seed yield and its components in rice (Oryza sativa L.)

An experiment comprising 75 F IS + 28 parents was conducted in Randomized Block Design in three replications under irrigated condition during Kharif 2001 and 2002. The observations were recorded on grain yield plant⁻¹ (g), seedling length (cm), number of leaves planrl, days to 50% flowering, plant height (cm), tillers plant⁻¹, ear bearing tillers plant⁻¹, spikelets plant⁻¹, gains panicle⁻¹, spikelet fertility per cent, test weight (g), biological yield (g) and harvest index. Phenotypic and genotypic coefficient of variation were higher for grain yield plant⁻¹, spikelet fertility per cent, spikelets plant⁻¹, ear bearing tillers plant⁻¹, test weight and tillers plant⁻¹. High heritability estimates in broad sense were obtained for most of the characters except seedling length and plant height, while narrow, sense heritability estimates were higher for test weight and moderate for rest of the characters except seedling length, number of leaves, spikelets panicle⁻¹, biological yield and grain yield plant⁻¹, which exhibited low heritability. High heritability coupled with high genetic advance were recorded for test weight, spikelet fertility per cent, grain yield plant⁻¹, harvest index, biological yield and number of spikelets plant⁻¹.