COMPARATIVE STUDY OF COWPEA GERMPLASMS DIVERSITY FROM GHANA AND MALI USING MORPHOLOGICAL CHARACTERISTICS

Abstract

Cowpea improvement can be enhanced by knowledge of genetic diversity available between and within local and regional gene banks. This variability is the foundation of all cowpea improvement programs. A total of 94 accessions (47 from Ghana and 47 from Mali) was used for this study. Twelve qualitative and twenty quantitative traits such as flower color, growth habit, raceme position, seed shape, day 50% flowering, day 50% maturity, plant height, seed length and seed weight were used to assess collections. Data collected from different morphological traits were analyzed using XLSTAT 2013. Principal component analysis, scatter plot matrix and clustering separated the accessions according to some qualitative and quantitative traits. Accessions were classified based on their morphological relationships using un-weighted pair-group average Cluster Analysis. Results showed a relatively low level of genetic diversity between and within both germplasm; levels of similarity ranged between 0.95 to 0.069 for combined qualitative and quantitative data. However, some morphological traits discriminated more efficiently between the accessions than others. Few groups of the accessions were different from other accessions for some important traits. Implications of the variability in cowpea improvement are discussed.