Species diversity, molecular phylogeny and ecological habits of Cyanosporus (Polyporales, Basidiomycota) with an emphasis on Chinese collections

Cyanosporus is a genus widely distributed in Asia, Europe, North America, South America and Oceania. It grows on different angiosperm and gymnosperm trees and can cause brown rot of wood. Blue-tinted basidiomata of Cyanosporus makes it easy to distinguish from other genera, but the similar morphological characters make it difficult to identify species within the genus. Phylogeny and taxonomy of Cyanosporus were carried out based on worldwide samples with an emphasis on Chinese collections, and the species diversity of the genus is updated. Four new species, C. flavus, C. rigidus, C. subungulatus and C. tenuicontextus, are described based on the evidence of morphological characters, distribution areas, host trees and molecular phylogenetic analyses inferred from the internal transcribed spacer (ITS) regions, the large subunit of nuclear ribosomal RNA gene (nLSU), the small subunit of nuclear ribosomal RNA gene (nSSU), the small subunit of mitochondrial rRNA gene (mtSSU), the largest subunit of RNA polymerase II (RPB1), the second largest subunit of RNA polymerase II (RPB2), and the translation elongation factor 1-α gene (TEF). Our study expanded the number of Cyanosporus species to 35 around the world including 23 species from China. Detailed descriptions of the four new species and the geographical locations of the Cyanosporus species in China are provided.