Effects of fast neutron irradiation on selected Nigerian cowpea (Vigna unguiculata (L.) Walp) landraces

Abstract

Induction of beneficial mutants was intended when different landraces of cowpea were exposed to different doses of fast neutron irradiation (FNI). Cowpea as an economically important crop in sub-saharan Africa was selected to broaden the available gene pool for selection and improvement of the crop. Six cowpea (Vigna unguiculata (L.) Walp) landraces namely Milki, Jan wake, Dan Shika, Kannanado, Black eye pea and Sampea7 were exposed to varying doses (3.44×10-2 µs, 6.88×10-2 µs, 10.32×10-2 µs and 13.76×10-2 µs) of fast neutron irradiation derived from an Americium-Beryllium source with a flux of 0.86 × 10-2 µsh-1. Results on effects of the different irradiation treatments on plant growth characters (germination percentage, survival to maturity, number of leafs per plant and total leaf area) at M1 generation were determined. Result showed that all irradiation treatments caused a general significant (P˂0.05) reduction in germination percentage, survival to maturity, number of leafs per plant and total leaf area of the plants used in the study irrespective of the landrace. There was a greater reduction of plant growth characters at higher doses of 10.32×10-2 and 13.76×10-2 µs compared to lower doses of 3.44×10-2 and 6.88×10-2 µs. This study revealed an inhibitory vegetative growth performance of the cowpea landraces when exposed to higher doses (10.32×10-2 µs and 13.76×10-2 µs) of FNI. It is therefore, assumed that such inhibitory effects on vegetative parameters may lead to reduction in certain yield attributes of the plant.