Induction of mutation played a vital role in the crop improvement among methods of plant breeding. Genetic improvement through induced mutation was found to be very effective for induction of variability in the quantitative and qualitative characters. The mutagenic effect of gamma rays (200Gy, 300Gy and 400Gy) and Electron beam (200Gy, 300Gy and 400Gy) alone or in combination (200+200Gy, 300+300Gy and 400+400Gy) on frequency and spectrum of chlorophyll and micromutations in cultivar, ADT 3 and CO 6 of blackgram was studied. Micro and macro-mutants play an important role to assess the effectiveness of the mutagens. The individual treatment of electron beam was found to be more efficient than gamma rays and combined treatment to induce chlorophyll mutants. Five different types of chlorophyll mutants such as, chlorin, albino, xantha, viridis and xanthoviridis in M-2 generation were observed. The chlorophyll mutants were scored from 7 to 10 days after sowing. Among the chlorophyll mutations, xanthoviridis was the most frequent mutant in both the varieties. The highest frequency of chlorophyll mutants was reported at dose of 200 Gyelectron beam. Thus, it is concluded that the lower doses of mutagens are more useful to induce different type of chlorophyll mutants.
