Value of Seed Protein Profile in the Taxonomy of cultivars of Capsicum in Nigeria

Abstract

Over a decade, the taxonomy of the genus Capsicum in Nigeria  has remained largely unrevised, unclassified and unidentified. As such, there is a dearth of information on the proper identification of Capsicum spp and relatives found in the country. The aim of this study was to re-examine the taxonomic status of the Capsicum in Nigeria in order to establish genetic diversity between them for proper identification and classification. Sodium dodecyl  polyacrylamide gel electrophoresis of total seed protein was performed on five varieties of Nigerian Capsicum spp., following standard procedures. Six protein bands were observed across the five cultivars of Capsicum, of which 12-14 Kda was the only polymorphic band. Only C. fructescens var. ijosi and C. fructescens var. sombo were unique for manifesting 20-24 and 15-16 Kda bands respectively. Dendrogram of analysis obtained resolved the taxa into two distinct groups. In the first group were cultivars of C. fructescens var. ijosi and sombo while in the second group were C. chinense, which was distinctly separated from C. fructescens var. bawa and C. annum. Artificial dichotomous key was constructed for the identification of members of the genus Capsicum available in Nigeria based on the protein profiles of their seeds.

Keywords: Capsicum, seed protein, electrophoresis, identification, diversity.