벼 幼穗分化前後에 γ-線照射가 穗發達 및 葉緣體變異에 미치는 影響

The Effects of Gamma Irradiation on Developing Panicle in Rice

Present experiments were attempted to clarify the biological effects of gamma irradiation on the growing rice plants in terms of heading time, culm and panicle length, number and mean length of prima ry or secondary rachis branches per panicle, number of spikelets per panicle, and sterility in M₁, generation, and chlorophyll mutation in M₂ generation. 1. Radiosensitivity was highest when the rice plant was irradiated at stage immediaitely before the differentation of the panicle primordia. 2. Regardless of the growth stage at which the treatment was carried out, the panicle length was shortened and the number of both primary and secondary rachis branches were decreased. 3. Generally irradiation of growing plant brought about retardy heading date, and the delaying was conspicuous when irradiation was conducted at earlier stages of growth. 4. Frequency of chlorophyll mutation in M₂ generation was highest when the plants were irradiated 37 and 41 days before panicle emergence.