RAPD markers demonstrate genetic diversity in Pterocarpus angolensis from Zimbabwe and Zambia

Abstract

Understanding the availability, extent and apportionment of genetic variability in natural populations of the southern African savanna tree Pterocarpus angolensis can provide reliable information on the evolutionary history and phylogenetic relationships of P. angolensis populations. This information will aid strategies for successful domestication, conservation and sustainable exploitation of the species. In this study random amplified polymorphic DNA (RAPD) analysis was employed to assess genetic diversity of P. angolensis, characterising 60 genotypes originating from four Zimbabwean and two Zambian provenances. Four RAPD primers each generated 11 to 15 scorable bands, with a total of 50 reproducible bands of which 88% were polymorphic. Analysis of molecular variance partitioned the greatest proportion of variability to within population (80.82%). Euclidean distance gave a phiST value of 0.192, indicating a moderately high level of population differentiation. The degree of population diversity found in this study, with two clear strong population structures for most genotypes from Nyazura and Gokwe and the rest of the populations with slight weak structures, suggests that all provenances tested could be beneficially utilised in a domestication programme for P. angolensis.

Keywords: domestication, genetic variation, population diversity, Pterocarpus angolensis, RAPD