Genetic diversity of Garcinia kola in South-west Cameroon

B.Sc. Benson Agyepong

Master's thesis

Abstract:

Garcinia kola (Heckel) is an indigenous multipurpose fruit tree, originating in Western and Central Africa. It is a highly valued for the medicinal efficacy of the bark, root, seed in the treatment of common ailments such as cough, bacterial infection, etc. Especially seeds of G. kola are frequently used in Cameroon for treatment of a wide range of health problems. Despite its frequent usage, the domestication process of this tree is at its beginning and throughout its distribution area. The seeds are mostly harvested from the wild, which can lead to endangering of the species. Moreover, there are various research papers published on this breed’s bioactive substance, nutritional content etc, however, the primary information on genetic structure, diversity, and distribution of existing populations crucial for domestication and conservation efforts of the species is still lacking. The aim of this study was to assess the genetic diversity of G. kola in Cameroon. In total, 75 individual trees from four populations were sampled in Southwest Cameroon and DNA was extracted from the seed coat. Twenty arbitrary RAPD primers were used for screening, and seven were chosen for final analysis based on polymorphism shown. PCR products were visualized on agarose gels and bands scored for presence or absence. A total number of 135 loci were obtained, all of them polymorphic, showing 100% polymorphism. The overall values of Nei’s gene diversity and Shannon’s diversity index (h=0.20, I=0.34) indicate high levelsof genetic diversity in the analysed individuals. However, the index of Nei’s genetic distance between populations reached very low values, showing lack of population structuring. These values are quite typical for natural populations with low selection and domestication pressure. This study contributes to the description of population genetics of G. kola. The results, together with morphological and biochemical data, can lead to better management, conservation, and utilization of G. kola gene pool.

Keywords

Diversity, Bitter cola, Cameroon, medicinal plants, distribution, RAPD

Language used: English

Date on which the thesis was submitted / produced: 26. 7. 2021

Thesis defence

• Supervisor: doc. Ing. Bohdan Lojka, Ph.D.

Czech University of Life Sciences Prague

Faculty of Tropical AgriSciences

Master programme:
Tropical Forestry and Agroforestry