Abstract
In order to get mutational RBE of fast neutrons in mature sperm of the silkworm, irradiation was perfomed at late pupal stage. A series of 137Cs γ-ray irradiation experiments were run in parallel with those 14MeV neutrons. For the determination of mutation frequency visible recessive egg colour mutations were used as markers.
1.Dose-frequency curves for recovered mutations increased linearly with the increasing dose for both radiations, which indicates that they are due to single-hit events. Whereas, the frequency curves for mosaics, were rising non-linearly, indicating that they are of multi-hit nature.
2. 14MeV neutrons were approximately 6 times as efficient as γ-rays in producing recessive visible mutations in mature sperm of the silkworm. Hence, RBE values of 14MeV neutrons are larger in mature sperm than in spermatogonia.
3. For the production of mosaics RBE of 14MeV neutrons relative to 137Cs γ-rays was about 5.
