Phylogenetic relationships among Rhizopogon boninensis and other subgenera of the genus Rhizopogon based on ITS rDNA sequences

Rhizopogon (Basidiomycota, Boletales) is the most speciose genus of hypogeous to subepigeous fungi and forms ectomycorrhizas narrowly restricted to the Pinaceae. Among them, Rhizopogon boninensis was long regarded as an endemic species of Bonin Islands, Japan. Our study verified the distribution of R. boninensis outside of Japan by both morphological characteristics and phylogenetic analysis. Furthermore, the phylogenetic tree based on ITS rDNA sequences provided valuable evidence on the phylogenetic relationships of R. boninensis in subgenus Rhizopogon with other Rhizopogon subgenera for the first time.