Evolution of Filamentous Ascomycetes Inferred from LSU rDNA Sequence Data

Abstract

The nuclear LSU rRNA gene was examined in order to evaluate the current phylogeny of ascomycetes, which is mainly based on nuclear SSU rRNA data. Partial LSU rRNA gene sequences of 19 ascomycetes were determined and aligned with the corresponding sequences of 13 other ascomycetes retrieved from Genbank, including all classes traditionally distinguished and most of the recently accepted classes. The classification based on SSU rDNA data and morphological characters is supported, while the traditional classification and classifications based on the ascus type are rejected. Ascomycetes with perithecia and cleistothecia form monophyletic groups, while the discomycetes are a paraphyletic assemblage. The Pezizales are basal to all other filamentous ascomycetes. The monophyly of Loculoascomycetes is uncertain. The results of the LSU rDNA analysis agree with those of the SSU rDNA and RPB2 gene analyses, suggesting that most classes circumscribed in the filamentous ascomycetes are monophyletic. The branching order and relationships among these classes, however, cannot be elucidated with any of these data sets.

Perithecial ascomycetes from the 400 million year old Rhynie chert: an example of ancestral polymorphism

“…While Paleopyrenomycites provides some information about early stages in centrum development, all the features used to characterize a single pattern cannot be documented conclusively. The limited sections that are available suggest that the fossil has more in common with centrum development of the Xylaria-type, but as noted by some authors, centrum development ultimately might prove to be a highly variable character and of little systematic importance (Lumbsch 2000). Where known, the anamorphic stage of these extant families is of the blastic type while in the fossil conidiogenesis appears to be thallic.…”

Lichen Systematics: The Role of Morphological and Molecular Data to Reconstruct Phylogenetic Relationships

“…The ascohymenial type appears to be plesiomorphic , but Loculoascomycetes are either reconstructed as monophyletic (Liew et al 2000;Liu and Hall 2004) or polyphyletic (Lindemuth et al 2001;Lumbsch et al 2000. At present, it thus seems that neither ascoma type nor ontogeny can be used to define any major lineages of ascomycetes ).…”

Early Molecular Investigations of Lichen-Forming Symbionts: 1986–2001

“…DEPRIEST variable nuLSU sequences alone (84) or in combination with nuSSU and proteincoding genes have supported class and order relationships found in the nuSSU phylogenies (90,113,114). However, even when groups are recognized in many independent analyses, bootstrap or jackknifing methods may not provide strong statistical support.…”