RIBOSOMAL DNA SEQUENCE ANALYSIS PLACES THE YEAST-LIKE GENUS SYMBIOTAPHRINA WITHIN FILAMENTOUS ASCOMYCETES

摘要

Cladistic analysis of partial sequences from the small subunit ribosomal DNA was used to infer the phylogenetic placement of Symbiotaphrina among a diverse range of ascomycete taxa. Tree topologies obtained using parsimony criteria fail to support previous hypotheses of a close relationship with either Taphrinales or Saccharomycetales; rather, the data suggest that the lineage containing Symbiotaphrina forms part of the early radiation of ascocarpic ascomycetes. The closest relatives of Symbiotaphrina remain obscure. Analyses confirm the monophyly of the two species of the genus and provide preliminary evidence for their phylogenetic distinctiveness. These results are discussed in relation to the evolution of fungal-insect symbiotic relationships. [References: 44]