Additions to the knowledge of Ganoderma in Thailand: Ganoderma casuarinicola, a new record; and Ganoderma thailandicum sp. nov.

Abstract

<i>Ganoderma</i> is a cosmopolitan genus of mushrooms, which can cause root and butt rot diseases on many tree species. Members of this genus are particularly diverse in tropical regions. Some <i>Ganoderma</i> spp. are medicinally active and therefore are used to treat human diseases or as a dietary supplement. In this study, three <i>Ganoderma</i> strains were collected in tropical southern Thailand. Phylogenetic analyses of combined ITS, LSU, TEF1α and RPB2 sequence data indicated that the three strains grouped in a distinct lineage within laccate <i>Ganoderma</i>. One strain was collected from Surat Thani Province clustered in the <i>G. casuarinicola</i> clade with high statistical support (MLBS = 100% / MPBS = 98% / PP = 0.96), while the other two strains of <i>Ganoderma</i>, collected from Nakhon Si Thammarat Province, formed a distinct well-supported clade (MLBS = 100% / MPBS = 100% / PP = 1.00) and are described here as a new species. <i>Ganoderma casuarinicola</i> is reported here as a new record to Thailand. Morphological differences of the two taxa and their closely related taxa are discussed. Colour photographs of macro and micro morphological characteristics and a phylogenetic tree to show the placement of the new record and new species are provided.