Studies on Effect of Mutagens on Quantitative Characters in M2 and M3 Generation of Horsegram [Macrotyloma uniflorum (Lam.) Verdc]

Background: Induction of mutation plays an important role in the breeding programme among modern methods of plant breeding. Genetic variability is prerequisite for crop improvement and through induced mutation it was found to be very effective for creating variability in the quantitative and qualitative characters. Hence, the present study was aimed to induce genetic variability within short time. In the present investigation positive as well as negative impact on quantitative traits were recorded. Methods: The experiment material comprised of seeds of horsegram [Macrotyloma uniflorum (Lam.) Verdc] variety Paiyur 2 which was subjected to ethyl methane sulphonate (02, 0.3, 0.4 and 0.5%), gamma radiation (100, 200, 300 and 400 Gy) and combination treatments. The mutations affecting gross morphological changes in growth and yield characters such as plant habit, flowering, pod morphology, maturity and seed yield were scored as quantitative characters. The micro mutations at population level can be easily detected in the form of increased variations for quantitative traits in the segregation of mutagen treated populations. Micro mutations can alter morpho-physiological characters hence they are of a particular interest to the plant breeders. ANOVA test was performed to determine the significant differences and duncan’s multiple range test (p=0.05) to compare the differences among treatment means. Result: Among the twenty-five treatments studied both the mutagens, gamma radiations and Ethyl Methane Sulphonate proved to be very effective to induce variability in quantitative traits in M2 and M3 generations. The results of Duncan’s multiple range test analysis revealed that the treatment of mutagens in combinations induced more positive effects as compared to that of using alone. The combined treatments were found positive for improvement of primary branches per plant, no. of pods per plant, pod length, no. of seeds/pod and seed yield per plant in M2 and M3 generations whereas the treatment of gamma irradiation imparted its significant role for improvement of plant height, days required for 50% flowering, days to maturity and 1000 seed weight in both M2 and M3 generations whereas the treatment with Ethyl Methane Sulphonate is useful for improving no. of pods per plant and no. of seeds/pod in M2 generation alone.