Molecular systematics of the Hypocreales: a teleomorph gene phylogeny and the status of their anamorphs

Abstract

Phylogenetic relationships among 40 species in the Hypocreales and Clavicipitales were inferred from sequence data obtained from the nuclear large-subunit ribosomal DNA. Cladistic analysis of these data support the monophyly of the Hypocreales, with the Clavicipitales derived from within the Hypocreales. Four groupings were resolved and are informally designated as the Hypocrea, Claviceps, Bionectria, and Nectria groups. Phylogenetic placement of teleomorphs including Melanospora and cleistothecial taxa, such as Heleococcum, Mycoarachis, and Roumegueriella, demonstrate the facility of molecular phylogenies to accommodate taxa with highly modified morphologies. Similarly, the hypocrealean origins of the anamorph species Verticillium lecanii and Acremonium chrysogenum illustrate the potential of the molecular phylogenetic approach to accommodate anamorph isolates within the context of a teleomorph phylogeny. Together these results suggest that a comprehensive classification of the Hypocreales, inclusive of teleomorph and anamorph states, is attainable through a molecular phylogenetic approach. Key words: Ascomycotina, Clavicipitaceae, Hypocreales, phylogeny, pyrenomycete, rDNA.