Phylogeographic relationships in the polypore fungus Pycnoporus inferred from molecular data.

The genus Pycnoporus forms a group of four species known especially for producing high redox potential laccases suitable for white biotechnology. A sample of 36 Pycnoporus strains originating from different geographical areas was studied to seek informative molecular markers for the typing of new strains in laboratory culture conditions and to analyse the phylogeographic relationships in this cosmopolitan group. ITS1-5.8S-ITS2 ribosomal DNA and partial regions of ß-tubulin and laccase lac3-1 gene were sequenced. Phylogenetic trees inferred from these sequences clearly differentiated the group of Pycnoporus cinnabarinus strains from the group of Pycnoporus puniceus strains into strongly supported clades (100% bootstrap value). Molecular clustering based on lac 3-1 sequences enabled the distribution of Pycnoporus sanguineus and Pycnoporus coccineus through four distinct, well supported clades and sub-clades. A neotropical sub-clade, grouping the P. sanguineus strains from French Guiana and Venezuela, corresponded to P. sanguineus sensu stricto. A paleotropical sub-clade, clustering the strains from Madagascar, Vietnam and New Caledonia, was defined as Pycnoporus cf. sanguineus. The Australian clade corresponded to P. coccineus sensu stricto. The Eastern Asian region clade, clustering the strains from China and Japan, formed a P. coccineus-like group. Laccase gene (lac 3-1) analysis within the Pycnoporus species can highlight enzyme functional diversity associated with biogeographical origin.