抄録
1. In the autumn of 1958, dormant seeds of a wheat variety, “Aoba-Komugi”, were immersed for 2 weeks in the solution of Na2H32PO4 with the doses of 1.0, 2.5, 5.0, 7.5 and 10.0μc/seed, respectively.
2. The survival rate decreased with the increase of radioactivity, while the chromosomal aberration rate increased proportionally with the increase of radioactivity.
3. 32P has different effects on different spikes in a plant as in X-ray. The main types of chromosomal aberrations observed at MI of PMC's were non-pairing, translocations, deficiencies, monosomics, iso-chromosomes and various combinations of these aberrations. Above all, non-pairing and translocations have occurred comparatively frequently.
4. The differences of chromosome numbers and of meiotic behaviors were found not only among spikelets of a spike but also among anthers of a floret.
