Survival Frequency and Spectrum of Induced Mutations in Penicillium Vermiculatum Dangeard Following Conidial Exposures to UV, X-Rays And Gamma Rays

A comparative study on the sensitivity of UV, X-rays and gamma rays on conidia of Penicillum vermiculatum has been done. LD50 with UV-rays was shown with less than 60 second treatment at a dose of 6 × 10³ ergs/mm². Beyond 240 second treatment i.e. 2.4 × l0⁴ ergs/mm² the survival per cent remained almost the same indicating resistance of surviving spores to the action of UV radiation. With X-rays an increase in the germination per cent of conidia was noticed at dosages of 5 and 10 Kr. Abrupt fall in the survival per cent was observed with increasing dosage of X-rays. A wide range of biochemical and morphological mutant was obtained with UV irradiation as compared to those with X-rays. Nicotinic acid requiring mutants occurred frequently with X-rays and methionine requiring ones with gamma-rays. Compact colonial mutants were induced freely with X-rays and violet pigment producing ones with gamma-rays.