Phylogenetic relationships of the hyphomycete generaChaetopsina andKionochaeta based on 18S rDNA sequences

A setiform dematiaceous hyphomycete,Kionochaeta spissa was newly collected and isolated from evergreen broad-leaved forests in the southern parts of Japan. Except for its dematiaceous nature, the species is morphologically similar to a nectriaceous hyphomycete,Chaetopsina fulva. The morphology and cultural properties of the Japanese isolates ofK. spissa were described, and the phylogenetic relationships betweenChaetopsina (C. fulva (type species)) andKionochaeta (K. ramifera (type species),K. spissa andK. ivoriensis) were inferred based on nuclear encoded small subunit (18S) rDNA sequences using the neighbor-joining method.Chaetopsina andKionochaeta were found to be phylogenetically related to the Hypocreales and Sordariales, respectively. Both should be maintained as separate genus for phylogenetic classification. The morphological resemblance especially betweenC. fulva andK. spissa is an example of the convergent evolution.