Variation in quantitative characters in the F$sub 2$ population derived from unirradiated and irradiated hybrids of rice

The hybrid seeds from japonica × indica crosses of Oryza sativa were irradiated to induce and measure the variability for quantitatively inherited characters and recover types combining good quality of indica and resistance to bacterial blight available in japonica parents. The results suggessed that the irradiation of F: seeds resulted in significant increase in the range of variation for most of the characters observed in the F2 generation. However, the means either remained same or shifted to either direction. The recovery of segregants with good quality coupled with bacterial blight resistance, was more in the irradiated than in the non-irradiated F1 population.