Taxonomy and species diversity of Ganoderma species in the Garden Route National Park of South Africa inferred from morphology and multilocus phylogenies

Abstract

Ganoderma is a cosmopolitan genus that encompasses species with cultural, economic, and pathogenic importance. Despite the importance of this genus, knowledge pertaining to the species diversity of Ganoderma in South Africa is limited. This study aimed at elucidating the identity and phylogenetic placements of Ganoderma samples obtained during a survey of wood-rotting fungi in the Garden Route National Park (GRNP) of South Africa, supplemented with isolates obtained from other localities across the country. Identification was achieved by means of multilocus phylogenetic inference combined with morphological evaluation. In total, eight distinct species of Ganoderma were recovered from different hosts and localities across the country. Of these, Ganoderma cf. cupreum and Ganoderma cf. resinaceum represent possible new records for South Africa. Two novel species are described, namely, G. eickeri. and G. knysnamense. Ganoderma eickeri, sp. nov., is characterized by a triquetrous and broadly attached basidiome, a sulcate or zonate yellowish brown to brown pilear surface, and ovoid to ellipsoid basidiospores. Ganoderma knysnamense is distinguished by an applanate to ungulate, sometimes convex, dimidiate to broadly attached basidiome, a chocolate-brown pilear surface covered with a hard woody-like crust and ellipsoid, broadly ellipsoid to ovoid basidiospores. The discovery of two new Ganoderma species in this study raises the known Ganoderma species in South Africa to 13.