Assessment of Somatic Mutagenic Effects on Different Black Gram Varieties by Chemical Mutagen Ethyl Methane Sulfonate (EMS)

Abstract

Black gram [Vigna mungo (L.) Hepper], a nutritionally rich pulse crop, suffers from narrow genetic variability due to its cleistogamous nature, limiting conventional breeding progress. Induced mutagenesis using chemical mutagens offers a viable approach to generate novel genetic variability. This study evaluated the somatic mutagenic effects of Ethyl Methane Sulfonate (EMS) at five concentrations (0.1%, 0.2%, 0.3%, 0.4%, and 0.5%) on two black gram varieties, VBN 8 and VBN 10, using germination towel and pro-tray methods. Parameters assessed included germination percentage, root length, shoot length, germination index, and chlorophyll content. Results demonstrated a significant dose-dependent reduction in all growth parameters with increasing EMS concentration in both varieties and methods. In the germination towel method, VBN 8 showed germination percentages ranging from 72.5% (0.1%) to 60.0% (0.5%), while VBN 10 exhibited a sharper decline from 72.5% to 47.5%. Root length reduction reached 66.81% in VBN 8 and 65.21% in VBN 10 at 0.5% EMS. Similarly, shoot length reduction was more pronounced in VBN 8 (73.5%) compared to VBN 10 (22.16%) at the highest dose. The LD50 was projected at approximately 0.4–0.5% EMS for both varieties. Chlorophyll content exhibited irregular variation, suggesting differential mutagenic sensitivity between genotypes. These findings establish the baseline mutagenic effectiveness and efficiency of EMS for future M₂ generation screening programs aimed at developing improved black gram genotypes with enhanced yield, quality, and stress tolerance. The present investigation comprehensively established the dose-dependent somatic mutagenic effects of EMS on two elite black gram varieties, VBN 8 and VBN 10, under both germination towel and pro-tray conditions.