Genetic Variability Study Among Ten Cultivars of Cowpea (Vigna unguiculata L. Walp) Using Morpho-agronomic Traits and Nutritional Composition

Abstract

Ten cultivars of cowpea grown in the screen house facility at Botanical garden, University of Ilorin, Nigeria were evaluated for genetic similarity and variability. Data were collected on vegetative, fruiting and seed characters. Proximate analysis was conducted to determine variation in nutrient composition of the seeds at harvest. The results showed considerable variations in growth and yield characters evaluated. Cultivars NGB/06/047, IFE BROWN 2012 and IT98K-133-1-1 had optimal growth performance with respect to fruiting and seed yield parameters. Proximate results indicated that crude protein varied from 23.42-26.78%. Ash content ranged between 3.60-4.21%, crude fibre varied from 2.10-2.98%, and carbohydrates 56.10-59.59%. Principal components analysis revealed that first principal components (majorly fruiting and seed characters) accounted for 26.63% observed variation, followed by the second component (23.05%) which are mainly vegetative parameters while third (13.82%) consisting of nutritional variations. The cultivars were divided into two broad genetic groups (A&B). Group A consist of two clusters which members showed low performance in terms of economic traits and group B comprised two clusters of superior cultivars for most of the traits studied. Variability as expressed in the studied cultivars could be useful for understanding genetic diversity of selection of cultivars with novelty in vegetative growth, yield and nutrition composition in the process of breeding programme and crop production.The Journal of Agricultural Sciences Vol. 10, No. 2, May 2015. Pp 119 - 130