Towards a phylogenetic classification of Cordyceps: ITS nrDNA sequence data confirm divergent lineages and paraphyly

Abstract

The ascomycetous genus Cordyceps accommodates endoparasitic species that attack arthropods or other fungi. Analyses of ITS nrDNA sequence data of 72 taxa from the teleomorph genera Cordyceps, Claviceps, Epichloe¨, and the anamorph genera Akanthomyces, Beauveria, Metarhizium, Hirsutella, Hymenostilbe, Paecilomyces, Polycephalomyces, and Tolypocladium assigned the taxa to four main evolutionary lineages not reflected in the current classification of Cordyceps. Ten subclades were recognized from separate analyses of data subsets. Judged from the ITS phylogenies, Cordyceps spp. with branched stromata were highly supported as a divergent lineage. Host specificity was found to be of limited phylogenetic significance, and several host shifts are suggested to have occurred during the evolution of Cordyceps. Similar ascospore morphology was not reflected in the phyletic groups, and closely related taxa showed large interspecific variation with respect to the number of segments in which the ascospores are divided. However, combinations of selected characters were found to delimitate some lineages, e.g. all Cordyceps spp. that attack hosts in the insect orders Coleoptera and Lepidoptera, and with non-immersed perithecia and clavate to acicular, brightly yellowish to reddish stromata, constituted a separate clade. Furthermore, all Cordyceps spp. with perithecia obliquely immersed in the stroma were recognized as a distinct monophyletic group. This clade is additionally characterized by the formation of anamorphs ascribable to the genus Hymenostilbe. The mycogenous Cordyceps spp. grouped in a separate subclade, interspersed by two cicadaen parasites and all Tolypocladium spp. except T. parasiticum. Tolypocladium and Beauveria were found to be polyphyletic. The included Claviceps and Epichloe¨taxa appeared to be derived within Cordyceps, thus making Cordyceps paraphyletic as suggested in other studies.

Genetic diversity of Hirsutella thompsonii isolates from Thailand based on AFLP analysis and partial beta-tubulin gene sequences

“…Based on b-tubulin analysis, we have observed that Hirsutella grouped with a branch that included C. bassiana, suggesting that this genus possesses affinities to the Hypocreales. Stensrud et al (2005) reported that Cordyceps species are commonly the teleomorphic stage of anamorph genera of many entomopathogenic fungi. The connection of Hirsutella and Cordyceps was first observed for the ant pathogen Cordyceps unilateralis whose anamorph is Hirsutella formiacarum (Petch, 1924) and several other Cordyceps species have been reported to be the teleomorphs of various Hirsutella species (Kendrick and Carmichael, 1973;Samson et al, 1988).…”

Multigene phylogeny and morphology reveal that the Chinese medicinal mushroom ‘Cordyceps gunnii’ is Metacordyceps neogunnii sp. nov.

“…There has been no thorough study of the collections of C. gunnii from China and Tasmania (Stensrud et al 2005, Sung et al 2007a. Only one publication (Liu et al 2002) suggested Chinese C. hawkesii and C. gunnii are conspecific based on 5.8S-ITS rDNA sequences.…”

Cordyceps locustiphila (Hypocreales: Cordycipitaceae) infecting the grasshopper pest Tropidacris collaris (Orthoptera: Acridoidea: Romaleidae)

“…There are estimated to be more than 400 species names under Cordyceps (Mains 1958, Stensrud et al 2005 although this is expected to be an underestimation of the *Corresponding author: pelizza@cepave.edu.ar extant global diversity (Hawksworth & Rossman 1997). A phylogenetic classification based on molecular data separated the species across three families, Cordycipitaceae, Clavicipitaceae and Ophiocordycipitaceae (Sung et al 2007b, Sanjuan et al 2014.…”