Induced mutations in cowpea, Vigna unguiculata (Leguminosae)

Two cowpea (Vigna unguiculata L. Walp) varieties, IT84E-124 and Vita 7 of the International Institute of Tropical Agriculture, Ibadan, were exposed to varying doses of chemical and physical mutagens. Optimum doses of 10mM EMS for 6hr and 0.1mM and 1.0mM NaN3 for 2hr, determined from seeding growth tests and 100R and 200R gamma radiations were applied to 2000 seed samples of each genotype. Screening of the M2 generation revealed that the mutagenic treatments induced morphological, physiological and biochemical changes in the genotypes. A spectrum of mutations which included variants with respect to anthocyanin pigmentation, leaf morphology, maturity date, male sterility and insect pest resistance qualities were observed. Lines with significant increases in yield parameters such as number of seeds per pod, peduncles per plant, 100 seed weight and seed storage proteins were selected.