Relationship of the genusCordyceps and related genera, based on parsimony and spectral analysis of partial 18S and 28S ribosomal gene sequences

A molecular phylogenetic study of selected species of three sub-genera of the genusCordyceps was undertaken, along with representatives of the generaAkanthomyces, Aschersonia, Gibellula, Hymenostilbe, Hypocrella, Nomuraea andTorrubiella, to examine their inter-relationship. Phylogenetic analyses of the data indicated that the Clavicipitaceae form a monophyletic group within the Hypocreales, while the monophyly ofCordyceps was not supported. Four clades were identified:Cor. militaris/Cor. pseudomilitaris; Cor. iranginesis/Cor. sphecocephala; Cor. intermedia/Cor. capitata; andCor. cylindrica/Nom. atypicola. The sub-genusNeocordyceps was shown to be monophyletic while the sub-generaEucordyceps andOphiocordyceps do not form monophyletic groups. The genusHypocrella appeared monophyletic, and radiated after the formation of the generaCordyceps, andTorrubiella. Akanthomyces arachnophilus andGi. pulchra, anamorphs ofTorrubiella species, formed a distinct clade that was separate from one formed by the scale insect pathogens,To. luteorostrata andPaecilomyces cinnamomeus, suggesting that this genus may be polyphyletic.