Induction of mutations in cowpea (Vigna unguiculata (L.) Walp.)

Abstract

Studies were undertaken to obtain precise information on the effects of six doses of gamma rays (5-30 krads) and seven concentrations of ethyl methanesulphonate (0.1-0.7 per cent) in cowpea, using the variety ' New Era'. The effectiveness and efficiency of different doses of the two mutagens in inducing chlorophyll mutations were estimated. (1) The germination of cowpea seeds was not affected by green rays even at the highest dose employed , whereas ethyl methanesulphonate inhibited germination and the reduction in percentage was progressive with increasing doses. (2) The survival of plants based on the number of seeds sown was reduced by both mutagens. Post germination mortality occured to a certain degree with gamma irrediation, whereas it did not occur to any considerable extent with ethyl methanesulphonate treatment. (3) A differential effect on the growth of shoot and that of root was observed with both mutagens in the present study. The growth inhibition was more for the shoot with gamma rays ,while ethyl methanesulphonate produced a higher degree of inhibition for the growth of root than for shoot.