Taxonomy of the Rhizopogon vinicolor species complex based on analysis of ITS sequences and microsatellite loci

Abstract

We are re-addressing species concepts in the Rhizopogon vinicolor species complex (Boletales, Basidiomycota) using sequence data from the internal-transcribed spacer (ITS) region of the nuclear ribosomal repeat, as well as genotypic data from five microsatellite loci. The R. vinicolor species complex by our definition includes, but is not limited to, collections referred to as R. vinicolor Smith, R. diabolicus Smith, R. ochraceisporus Smith, R. parvulus Smith or R. vesiculosus Smith. Holo- and/or paratype material for the named species is included. Analyses of both ITS sequences and microsatellite loci separate collections of the R. vinicolor species complex into two distinct clades or clusters, suggestive of two biological species that subsequently are referred to as R. vinicolor sensu Kretzer et al and R. vesiculosus sensu Kretzer et al. Choice of the latter names, as well as morphological characters, are discussed.

• fungal species concepts
• internal transcribed spacers
• microsatellite markers
• Rhizopogon

The authors thank Caprice Rosato for running countless GeneScan gels, and Nancy Adair and Gi-Ho Sung for help with sequencing. Susie Dunham, Jim Trappe and two anonymous reviewers have made valuable comments at different stages of this manuscript's development. This work would not have been possible without the type material housed at the University of Michigan Fungus Collection and provided to us by Robert Fogel and Patricia Rogers. The work was financed by joint venture agreement No. PNW-98-5113-1JVA and was supported partially by co-op agreement No. 01-CA-11261993-093-PNW, both from the U.S.D.A. Forest Service Pacific Northwest Research Station. Christopher Baycura has helped with design of the cover image.