Characterization of 60CO γ-ray induced pod trait of blackgram-A promising yield mutants.

Purpose: Blackgram (Vigna mungo (L.) Hepper) possesses natural flower dropping character with self-pollination, which was highly challenging to create variability through hybridization. Gamma irradiation is a powerful tool to induce genetic alteration and improvement in crops with beneficial mutants. Hence, the present investigation focused on finding out the mutant characters related to the improvement of the agronomic characters and yield-related traits by using gamma irradiation. Pod mutant isolated with fruitful agronomic trait at M2 (Mutagenic) generation was identified and isolated by gamma irradiation is a central focus in the present study, which enhances the yield of the blackgram.Materials and methods: Viable and uniform size of blackgram Vamban-4 seeds were irradiated at a different dose of 60CO (Cobalt) γ-rays viz., 200, 400, 600, 800, 1000, and 1200 Gray (Gy). The further generations were screened and raised to M3 and M4 plants to select the stable mutants with yield traits.Results: In the M2 generation, the following viable and pod mutants were identified, such as tall, dwarf, multipod, small pod, bold pod, striata pod. Morphological traits, such as plant height (PH), number of branches per plant (NBP), number of leaves per plant (NLP), number of cluster per plant (NCP), number of pods per plant (NPP), number of seeds per pod (NSP), pod length (PL), a hundred seed weight (HSW), seed yield per plant (SYP), were measured. Among the mutants, the increased morphogenetic traits were recorded in tall mutants (600 Gy), and the enhancement of yield characteristics noticed in multipod (800 Gy) and bold pod mutants (600 Gy). Compared to other doses, 600 Gy shows enhanced quantitative traits for blackgram improvement.Conclusion: The 60CO γ-rays induced genetic variation in the yield and its related traits and obtained pod mutants, which are useful to enhance the commercial value of Vigna species and crop improvement.

Effects of gamma radiation (γ) on biochemical and antioxidant properties in black gram (Vigna mungo L. Hepper).

Purpose: The present study focused on the role of primary metabolites, antioxidant activities in black gram (Vigna mungo L. Hepper) variety Vamban-4 under the impact of gamma irradiation. Materials and methods: The black gram seeds were irradiated at a different dose of gamma rays viz., 200, 400, 600, 800, 1000 and 1200 Gray (Gy), and analyzed the changes of biochemical and antioxidant contents. Results: Biochemical contents increased with increasing doses up to 800 Gy and reduced at higher dose viz.,1000 and 1200 Gy of gamma-ray treatment, while malondialdehyde content increased at higher dose 1200 Gy compared to control, this indicates that the formation of more lipid peroxidation at higher radiation level. Gamma irradiation enhanced the activity of antioxidant enzymes such as catalase, peroxidase and superoxide dismutase with increasing doses rather than control plants. These studies depict that the effect of gamma irradiation on seeds increased the free radicals compared to control, which emphasize by the Electron spin resonance spectroscopy (ESR). Gamma irradiated seed samples contain more fractions of protein, lipids, amino acid and polysaccharides compared to control plants observed from the Fourier infrared transform spectroscopy (FTIR). Conclusion: The present result concludes that cellular metabolites and the antioxidant enzymes increased and these alterations of metabolism due to the effect of gamma rays which induced free radical production in seeds and plants grown under irradiation stress. These results confirm that the exposure of gamma irradiation produced free radicals as well as counteract by antioxidant enzymes and in addition to that accumulation and alteration of primary metabolites.