Genetic Diversity Of Ganoderma Species In The North-Eastern Parts Of Namibia

Abstract

The genus Ganoderma Karst. (1881) is the largest and most complex genus of polypore fungi, characterized by the presence of pores instead of the gills on the lower side of the fruiting body. The colonisation of Ganoderma species on trees is noticed by the appearance of their cap shaped, hard, crusty and shiny fruiting bodies. Ganoderma extract have been used for centuries in Asia’s traditional medicine and to date Ganoderma mushrooms are an important source of modern medicinal and neutriceutical products in Asia. The objective of this study was to determine the genetic diversity among Ganoderma species, the traditional uses and natural hosts of Ganoderma species in the north-eastern part of Namibia. This study was carried out in two regions of the north-eastern part of Namibia; Kavango and Caprivi region. Face to face interviews were used to collect data about the uses. A total of 89 Ganoderma samples where used for PCR amplification. The genetic diversity was determined by using three different random amplified microsatellites namely ACA, CGA and CCA. Shannon-Weiner Index of diversity, Cluster Analysis (CA) and Principal Coordinate of Analysis (PCoA) were the three numerical classification methods used to analyse RAMS data in this study. All methods revealed existence of high genetic variation among Ganoderma isolates in the north-eastern parts of Namibia. CA exhibited 10 different clusters using 3 primers combination, while the first two principal coordinates of PCoA indicated Eigen values of 63.42 and 46.45 with a total variation of 12.20% and 8.93%. Shannon-Weiner Index of diversity indicated 2.16 total genetic diversity for Ganoderma in the north eastern parts of Namibia. Thirteen natural hosts of Ganoderma species were identified in both Kavango and Caprivi region. The most common host was Colosphermum mopane (18%) and the least common host were Ochna pulchra and Grewia bicolor both accounted for 1% of the total samples. Finally, three different uses of Ganoderma were identified mainly strengthening of infant bones (19%), immunity boost (13%) and avert of nose bleeding (4%). However 64% of the respondents did not know any use of Ganoderma.

Key words: Ganoderma, Genetic diversity, Kavango region, Caprivi region, host and RAMS.