Phylogenetic analysis of Xylaria based on nuclear ribosomal ITS1-5. 8S-ITS2 sequences

To elucidate phylogenetic relationships of Xylaria, nuclear ribosomal ITS1-5.8S-ITS2 regions from 22 strains of 18 species were sequenced. Members of Xylaria formed a monophyletic group and proved to be phylogenetically homogeneous except for Xylaria cubensis. Species of the section Xylorugosa were divided into three groups and X. cubensis belonging to the section Xyloglossa developed an independent lineage from the section Xylorugosa. Groupings were partially congruent with the morphological taxonomy. The stromal structure, ascal apex, ectostromal surface, perithecial structure, stipe differentiation and the germ slit of ascospores were phylogenetically significant characters in grouping Xylaria.