Taxonomic revision of Termitomyces species found in Ryukyu Archipelago, Japan, based on phylogenetic analyses with three loci

Fungi in the genus Termitomyces are external symbionts of fungus-growing termites. The three rhizogenic Termitomyces species T. eurrhizus, T. clypeatus, and T. intermedius, and one species similar to T. microcarpus that lacks pseudorrhiza, have been reported from Ryukyu Archipelago, Japan. In contrast, only two genetic groups (types A and B) of Termitomyces vegetative mycelia have been detected in nests of the fungus-growing termite Odontotermes formosanus. In this study, we investigated the relationships between the mycelial genetic groups and the basidiomata of Termitomyces samples from the Ryukyu Archipelago. We found that all the basidioma specimens and the type B mycelia formed one clade that we identified as T. intermedius. Another clade consisted of the type A mycelia, which showed similarity to T. microcarpus, was identified as T. fragilis. Our results indicate that the Japanese T. eurrhizus and T. clypeatus specimens should re-named as T. intermedius.