An overview of the higher level classification of Pucciniomycotina based on combined analyses of nuclear large and small subunit rDNA sequences

Abstract

In this study we provide a phylogenetically based introduction to the classes and orders of Pucciniomycotina (= Urediniomycetes), one of three subphyla of Basidiomycota. More than 8000 species of Pucciniomycotina have been described including putative saprotrophs and parasites of plants, animals and fungi. The overwhelming majority of these (~90%) belong to a single order of obligate plant pathogens, the Pucciniales (= Uredinales), or rust fungi. We have assembled a dataset of previously published and newly generated sequence data from two nuclear rDNA genes (large subunit and small subunit) including exemplars from all known major groups in order to test hypotheses about evolutionary relationships among the Pucciniomycotina. The utility of combining nuc-lsu sequences spanning the entire D1–D3 region with complete nuc-ssu sequences for resolution and support of nodes is discussed. Our study confirms Pucciniomycotina as a monophyletic group of Basidiomycota. In total our results support eight major clades ranked as classes (Agaricostilbomycetes, Atractiellomycetes, Classiculomycetes, Cryptomycocolacomycetes, Cystobasidiomycetes, Microbotryomycetes, Mixiomycetes and Pucciniomycetes) and 18 orders.

• basidiomycetes
• molecular phylogenetics
• parasitic fungi
• rDNA systematics
• Urediniomycetes

The authors thank Conrad Schoch and CBS for providing several cultures and Pat Crane for Pucciniales material used for the generation of sequence data. We thank Rytas Vilgalys and Lisa Bukovnik for access to the DNA sequencing facility at Duke University, Cindy Park for technical support at SBML and Manfred Binder for assistance with Bayesian analyses. This work was supported in part by grants from the National Science Foundation, DEB 0228657, DBI 0320875 and DEB-0090301, Research Coordination Network: A Phylogeny for Kingdom Fungi to M. Blackwell, J.W. Spatafora and J.W. Taylor. Mention of trade names or commercial products in thisPUBLICation is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.