MUTAGENIC EFFECTIVENESS AND EFFICIENCY OF GAMMA -- RAYS, SODIUM AZIDE AND THEIR SYNERGISTIC EFFECTS IN BLACK GRAM(V.MUNGO L.).

The usefulness of any mutagen in plant breeding depends not only on its effectivness but also upon its efficiency. Mutagenic effectiveness is a measure of the frequency of mutations induced by unit mutagen dose, whereas mutagenic efficiency is measure of proportion of mutations in relation to undesirable changes like lethality, sterility and meiotic aberrations etc. Synergetic as well as antagonistic effects may occur when various physical and chemical mutagens are used in combinations. The frequency of mutagenic efficiency and effectiveness was found to be highest at lower doses.