Identification of traded medicinal plants and edible orchids from Tanzania through DNA barcoding

Many wild medicinal plants and edible orchids in Tanzania are under threat from overharvesting. In this project we use DNA barcoding and metabarcoding to identify species from market samples such as roots, bark, and powders with the objective of identification of those species that are targeted most severely by this trade

Most medicinal plants and all edible orchids in Tanzania are harvested from the wild. This harvest puts a serious harvesting pressure on local plant populations. Especially when the use is commercialized and large quantities are extracted from the wild to meet the high demands. In this project we aim to map harvesting and trade in medicinal plants and edible orchids and to look at subsequent conservation issues that might arise from commercialized use and overharvesting. Because most plants are traded in morphological unidentifiable ways we employ DNA barcoding and high-throughput metabarcoding to identify which species are used as medicinal plants and edible orchids.

Medicinal plants

An estimated 80% of the Tanzanian population relies on medicinal plants for their primary healthcare, and most are harvested from the wild. This project focuses on plants sold at the medicinal plant markets in Dar-es-Salaam and Tanga, as this material is likely to be harvested from the Eastern Arc Mountains and Coastal Forests, two important biodiversity hotspots housing many endemic species.

Edible orchids – chikanda
Chikanda is a meat-resembling dish, which is prepared using terrestrial orchid tubers, peanuts and other ingredients. It is popular in Zambia, but there terrestrial orchid populations have become fairly depleted because of their use in chikanda, and orchid tubers for chikanda are now obtained from surrounding countries, such as Tanzania. Our aim is to investigate which orchids are harvested and in which quantities. Since the tubers from different chikanda orchid species are impossible to distinguish based on morphology only, we use DNA barcoding and metabarcoding to identify which species are used in chikanda. We analyse both unprepared orchid tubers as well as ready-made chikanda. In addition we conduct interviews with market vendors and chikanda collectors to learn more about the harvesting times, harvested quantities and sustainability issues arising from chikanda trade.

Involved people

Hugo de Boer

Sarina Veldman

Abdolbaset Ghorbani

Joseph Otieno

Image_Joseph Otieno.jpg

Kate Barbour

Tinde van Andel

Image_Tinde van Andel.jpg

Barbara Gravendeel

Published: Jan. 12, 2016
By: Hugo de Boer , Sarina Veldman , Abdolbaset Ghorbani
Tags: Disa , Satyrium , Habenaria , Orchidaceae , Orchids , DNA barcoding , Metabarcoding , Traditional Medicine , Molecular identification , Medicinal plants , CITES , TRAFFIC , Edible Orchids , Chikanda