Phylogenetic Relationships within Paxillus s. I. (Basidiomycetes, Boletales): Separation of a Southern Hemisphere Genus

Abstract This study aimed to test the monophyly and present a generic concept of PAXILLUS s. I. Of special interest were the Southern hemisphere representatives of this genus. Using the primer combination LR0R-LR5, DNA sequence data were generated from the nuclear encoded 28S gene. A data set containing 900 bases was created for 30 different species. Phylogenetic analysis showed 3 main monophyletic groups, also supported by morphological, anatomical, ecological and chemical data. Taxonomic interpretation of these clearly differentiated groups corresponded to the genera PAXILLUS s. str. and TAPINELLA and lead to the proposal of a new Southern hemisphere genus, AUSTROPAXILLUS, mycorrhizal with Nothofagus. New combinations are proposed.