抄録
1. The present study has been made in order to compare the results with effects obtained by radiophosphorus treatment previously reported.
2. Dormant seeds of Sesamum indicum L. were irradiated by X-rays at a dosage rate of 384.5r per minute. Doses varied from 8, 000 to 12, 000r.
3. The frequency of chromosome aberrations observed separately at MI and AI shows a linear increase according to the dosage, and the aberration frequency at AI was usually higher than that at MI.
4. Aberration types observed were strikingly like those induced with P32 treatments, but an inversion type was newly marked.
5. Abnormal cleavages in tetrad stage were observed.
