Contributions to the classification of Capsicum annuum L. and Capsicum frutescens L. in West Africa using morphological traits

Abstract

In West Africa, the genus Capsicum is represented by two cultivated species namely C. frutescens and C. annuum with different varieties. However, the taxonomic identity of these two species has been unresolved because they are morphologically related. There has been considerable debate on their status as two separate species or just varieties of one species. The study was aimed at assessing the variability and relatedness among the four varieties of the two closely related Capsicum species in West Africa. The varieties used in this study are C. annuum var. abbreviatum, C. annuum var. acuminatum, C. annuum var. grossum and C. frutescens var. baccatum. The varieties were morphologically characterized using 80 quantitative and qualitative standard descriptors from seedling emergence to plant maturity. Data collected were subjected to statistical analysis using SPSS statistical package, descriptive statistics and cluster analysis. The results revealed overlapping similarities in the morphology of the four varieties. Classification analysis based on data collected showed two distinct clusters by grouping varieties sharing close phenotypic similarities into distinct cluster. The differences observed among the varieties majorly in flower and fruit traits do not provide enough evidence to conceive that the collections are two separate species. Our results therefore support the inclusion of C. frutescens var. baccatum as a variety of C. annuum. Additional comparative molecular profiling is needed to fully understand the phylogenetic relationship among the cultivated Capsicum species in this part of the world.