COMPARISON OF FISSION NEUTRONS AND γ-RAYS IN RESPECT TO THEIR EFFICIENCY IN INDUCING MUTATIONS IN SILKWORM GONIA

Abstract
A study was made of the effects of fission neutrons on the induction of visible recessive mutations in early and late gonial cells of the silkworm. Dose-mutation frequency curve for fission neutrons was essentially the same as that for other radiations, showing a slow rise in the lower dose range but a rapid rise in the higher dose range. Mutation response to fission neutrons was almost similar for male and female gonial cells, although higher frequencies were observed for fission neutrons than for gamma-rays or 14 MeV neutrons. When radiation doses producing a frequency of 10-3 of visible recessive egg-color mutations were used as a criterion, the relative biological effectiveness of fission neutrons to gamma-rays was about 1.7 to 2.4 for early stage gonia and 3.0 to 4.2 for late stage gonia.