Induced mutagenesis in cowpea [Vigna unguiculata (L.) Walp] var. Arka Garima

A study was undertaken in a cowpea [Vigna unguiculata (L.) Walp.] var. Arka Garima to assess the efficiency and effectiveness of physical as well as chemical mutagens and to induce viable mutation in qualitative traits which could be utilized directly or introduced into cowpea improvement programme. Germination percent decreased in general with increase in dose/concentration of mutagens. The inhibitory effect on these characters was more prominent with gamma rays than with EMS. The frequency of chlorophyll mutation increased with the increase in dose/concentration. Wide spectrum of chlorophyll mutations were obtained in the present study which includes albino, xantha, chlorina, viridis and xantha-viridis. The lower and intermediate doses of gamma rays (200 and 300 Gy) and EMS (0.25% and 0.30%) are recommended as most effective and efficient for exploring variability and isolating promising mutants. Significant morphological variability was created which include abnormalities in growth habit, leaf, flower, pod and seed coat. The frequency of morphological abnormalities increased with increase in dose of gamma rays until 300 Gy followed by a decline. However, in chemical mutagen treated population, a linear decline in frequency up to 0.35% was seen followed by increase in higher concentrations.