Phylogenetic And Mycochemical Characterization Of Trametes Species From Northern Namibia

ABSTRACT

The objectives of this study were to confirm for the first time, the identity of Trametes mushrooms from Northern Namibia and then to generate information on local uses and bioactive compounds of these Trametes species. To achieve this, samples were collected from Ohangwena, Omusati, Oshikoto and Oshana regions and identified as Trametes species based on morphological features. These were a basidiocarp with concentric zones, brown, tan or grey colour and pores from 2-3 pores/mm to pores slightly bigger than 1 mm in diameter and lack of a pileus. TLC visualization reagents were used to identify compound groups in the hot water and organic extracts. The resulting chromatogram showed nine compounds separated in total and indicated presence of flavonoids, alkaloids and triterpene saponins. The disc diffusion method was used in bioassays of the extracts dissolved in DMSO and water. The highest zone of inhibition was 12 ± 1 mm by the DCM extract on Escherichia coli. The lowest inhibition observed was 9.7 ± 2.08 mm by the DCM extract on Bacillus subtilis. Interestingly, no inhibition was observed for the methanol and HWE extracts. These results differ from previous studies which reported that all organic extracts of Trametes were active against B. subtilis. A questionnaire was used to obtain indigenous knowledge of Trametes mushrooms in Northern Namibia. Questionnaire data analysed in SPSS revealed that 83.9 % of respondents in this study knew Trametes mushroom but only 70.4 % used it for medicinal purpose. The most common medicinal use of this mushroom was to calm bereaved people crying hysterically at burials and also to treat lung disease in cattle. The results from this study are novel since they have not been reported in literature before. Finally, fungal DNA was extracted and PCR performed with ITS1/ITS2 primers before sequencing. BLAST searches revealed that specimen collected were 99 % identical to Trametes polyzona. A phylogenetic tree was reconstructed using the Neighbour Joining method in MEGA version 6. The specimens collected from Northern Namibia were distributed in 6 clades mainly alongside Trametes species, Truncospora and more distantly Coriolopsis species. These results are consistent with previous works which agree that there is a close relationship between the genera Trametes, Coriolopsis (polyzona) and Pycnoporus.