Genetic diversity and cryptolepine concentration of Cryptolepis sanguinolenta (Lindl). Schlt. from selected regions of Ghana

Abstract Cryptolepis sanguinolenta is a medicinal plant widely used in the treatment of malaria in Ghana. The increasing demand for its roots coupled with harvesting of the plant in non-sustainable ways has resulted in a substantial decline in its wild populations. The study was conducted to (1) determine the relatedness among C. sanguinolenta wild populations, (2) identify genotypes with high active ingredient (cryptolepine) concentrations and (3) understand the extent to which cryptolepine levels are influenced by soil. Root and stem samples for the study was collected from the Eastern, Ashanti, Brong Ahafo and Volta Regions of Ghana. C. sanguinolenta plants were found in sandy loam/sandy clay loam textured soils of acidic (4.3) to near neutral (6.7) pH ranges. Semi Quantitative Thin Layer Chromatography (SQ-TLC) and High Performance Liquid Chromatography (HPLC) methods were used to quantify the cryptolepine content in the stem and root samples. Cryptolepine concentrations in the stem and roots were not significantly influenced by location. No correlation was found between the soil properties studied and the cryptolepine content in the roots. Results from both SQ-TLC and HPLC analyses indicated that cryptolepine concentrations were on average, twice as much in the roots (0.84 mg/100 mg plant material) compared to the stem (0.42 mg/100 mg plant material). Results of the genetic diversity study showed a genetic diversity of 25% with genetic distances ranging between 0.08 and 0.14. Samples from the same location had the least genetic distances. Bootstrapping performed on the marker data and coefficient of variation calculated from distance resolutions obtained from 800 markers, proved to be of sufficient resolution. Sample sites did not reflect distinct sub-populations, a result of possible gene flow between sampling locations. Findings from this study will be useful for developing domestication protocols for C. sanguinolenta and subsequently the cultivation of elite genotypes.