Submitted to: Inoculum
Publication Type: Abstract Only
Publication Acceptance Date: 7/17/2004
Publication Date: 8/1/2004
Citation: Frieders, E.M., McLaughlin, D.J., Szabo, L.J., Swann, E.C. 2004. Urediniomycetidae: Rusts and their close relatives [abstract]. Inoculum. 55:14.
Technical Abstract: The simple-septate auricularioid phytoparasites have figured prominently in historical concepts of the evolution of basidiomycetes in general and Uredinales (rust fungi) in particular. However, the relationship of these phytoparasites to the rust fungi and to other non-phytoparasitic simple-septate heterobasidiomycetes remains unclear. In this study, we apply cladistic methods to phylogenetic reconstruction and provide a natural taxonomic treatment for this group of fungi. Molecular cladograms were constructed using nuclear large and small subunit rRNA genes. Ultrastructural analyses of the septal pore apparatus and spindle pole bodies of select phytoparasitic taxa were performed; ultrastructural characters supported the molecular phylogenies. A natural group within the Urediniomycetes (Basidiomycota) has emerged consisting of the phytoparasitic Uredinales, Helicobasidium, Jola, Eocronartium, Platygloea, Herpobasidium and Insolibasidium, as well as the insect-associated Septobasidiales and the wood saprobe Pachnocybe. We propose the subclass Urediniomycetidae to house rusts and their close relatives. Based on this new cladistic phylogeny, taxonomic revisions will be required for some genera, families and orders within this subclass.