Phylogenetic relationships and taxonomy of Grifola (Polyporales)

Abstract

Grifola is a genus of poroid wood–rotting fungi that produces compound, multipileate basidiomes that are edible. We analyzed the phylogenetic and taxonomic diversity of Grifola on the basis of phylogenetic analysis of internal transcripter space (ITS) and β–tubulin (TUBB) DNA sequences, comparison of morphological features and host relationships. Results revealed a Northern Hemisphere (NH) and a Southern Hemisphere (SH) group of species. The NH clade is represented by G. frondosa (growing on Fagaceae and Betulaceae). The SH clade is represented by 4 taxa: G. gargal (growing on Lophozonia alpina and L. obliqua, Nothofagacea, in southern South America) is sister to a new taxon G. odorata (New Zealand, growing on Fuscospora spp., Nothofagaceae, and Metrosideros, Myrtaceae), and both are characterized by a strong almond smell, while G. sordulenta (southern south America, growing on Nothofagus dombeyi, Nothofagaceae), is sister to G. colensoi (New Zealand and Australia, growing on Fuscospora spp., Nothofagaceae and Eucalyptus spp., Myrtaceae). Results showed a complex evolutionary history of species evolving from Gondwanan ancestors and, in southern South America, Nothofagaceae was selected as principal host.