DNA barcoding Medicinal plants of South Africa.

M.Sc. (Botany)The market and public demand for medicinal plants over the past few decades has increased dramatically with more than 1 000 plant species actively traded for medicinal purposes throughout South Africa. Intensive harvesting of wild material is now acknowledged as a serious threat to biodiversity in this country. Also the substitution of a valuable commodity (medicinal plant) by a cheaper alternative (other plant species), either inadvertently due to misidentification, or deliberately to cheat consumers, raises some serious concerns as these adulterants may not be as effective or may even be toxic and cause harm to consumers. To add to the problem many species are either traded as dried leaf, root, bark products, or extracts and their identification becomes problematic. Therefore, DNA barcoding can help to provide a rapid and accurate identification tool for medicinal plants. In the current study I targeted the most commonly used medicinal plants in South Africa and produced a set of barcodes for fast and easy DNA-based species identification (rbcLa & matK). I tested the efficiency of core barcodes in the identification of medicinal plants using four main analyses, in the R package Spider 1.1-1. Here the extent of specific genetic divergence, DNA barcoding gap, BLAST test, and the ability to discriminate between species were assessed. Overall, the matK region was found to be a more useful tool for the species identification of medicinal plants in South Africa