LINDEMUTH, RALF*, NORA WIRTZ, IMKE SCHMITT, and H. THORSTEN LUMBSCH. FB9/Botanik, Universitaet Essen, Universitaetsstr. 5, 45117 Essen, Germany. - Evolution of filamentous Ascomycetes inferred from multiple-gene-analyses.
The current classification of Ascomycota is mainly based on
nuclear SSU rRNA data. Most classes circumscribed in the filamentous
Ascomycetes are based on nu SSU rRNA characters and morphology, but
some groups, such as Lecanoromycetes have only low bootstrap
support and the relationships of the classes is currently unresolved.
To improve this, we used a multi-gene-approach including nu SSU-, nu
LSU- and mitochondrial SSU-rDNA sequences of all traditionally
(morphologically) distinguished and most recently accepted classes of
filamentous Ascomycetes. Combined data sets were analysed
phylogenetically using maximum parsimony and minimum evolution, and
constrained topologies were tested with parametric bootstrapping. Most
of these classes were found to be monophyletic with high bootstrap
support. Lecanoromycetes showed a well-supported monophyly for
the first time. The classification based on SSU rDNA data and
different morphological characters, is supported, while the
traditional classification and classifications based on the ascus-type
are rejected. In contrast to single-gene-analyses also the branching
order and relationships among these classes could partly be
well-resolved. Our results suggest a basal position of the
Dothideomycetes in the Leotiomyceta.
Leotiomycetes and Sordariomycetes, as well as,
Chaetothyriomycetes and Eurotiomycetes form
Key words: Ascomycota, classes, fungi, molecular phylogeny, multiple-gene-analysis, nuclear SSU- and LSU- and mitochondrial SSU-rDNA