Studies on mutagen sensitivity, effectiveness and efficiency in urdbean [Vigna mungo (L.) Hepper]

Seeds of urdbean [(Vigna mungo (L.) Hepper] cultivars PDU-1 and T-9 were mutagenised with gamma-rays and EMS to determine their mutagen sensitivity, LD₅₀, mutagenic effectiveness and efficiency. The increasing doses of gamma-rays and EMS decreased germination, plant survival and pollen fertility. LD₅₀ values revealed that PDU-1 was more radio-and chemo-resistant than T-9. LD₅₀ values of gamma-rays and EMS can be helpful in experimental mutagenesis. The mutation frequency of gamma-rays was less in PDU-1 than in T-9. There was a parallelism between radio-sensitivity and chemo-mutability of urdbean genotypes. The average effectiveness and efficiency (pooled overdoses and genotypes) of EMS was 2.0–2.5 and 1.5–2.0 times higher than the gamma-rays, respectively. The lower doses of mutagens were more effective and efficient than the higher doses. Though effectiveness and efficiency computed by different methods varied in quantum, their relative proportion were comparable. A single method of studying mutagenic effectiveness and efficiency should be appropriate.