Abstract
1. As the previous reports (TORIYAMA & FUTSUIIARA 1962), this experiment was conducted with the aim to obtain some beneficial mutants in rice. 2. Water soaked seeds of a rice variety "Fujisa" ka No.5" were irradiated by X-ray. The breeding methods employed in the X1-X7 generations are shown in table 1. 3. Consequently, we found a number of mutations, most of which were lower in yield than the control (original variety). 4. However, a high yielding mutant line was obtained from the progeny of X2 variants selected as small morphological variant types, and was nominated as "Fukei No.54". 5. "Fukei No.54" having more many tiller as compared with that of the control, was higher in yield by about 8% than the original variety.
