Phylogenetic assessment of Chaetomium indicum and allied species, with the introduction of three new species and epitypification of C. funicola and C. indicum

Abstract

Historically, the Chaetomium indicum group contained six species with similar ascus and ascospore morphology. Large morphological variation in their branched ascomatal hairs often resulted in ambiguous species delimitation. In this study, morphological characters and the maximum growth temperature (MGT) are evaluated in light of phylogenetic relationships. Multigene phylogenetic analyses with ribosomal internal transcribed spacer (ITS), partial ribosomal large subunits (28S rDNA), β-tubulin, the translation elongation factor 1α (TEF1-α), and the largest subunit of RNA polymerase I{cyrillic, ukrainian}I{cyrillic, ukrainian} (RPB1) recognize eight well-supported lineages within the monophyletic C. indicum group. The eight lineages correspond to five known species and three new species described in this paper (i.e., C. pratense, C. subfunicola, and C. ramosissimum). Chaetomium dolichotrichum is resurrected, as it appears to be a distinct species from C. funicola. Chaetomium cancroideum, though phylogenetically consistent with C. funicola, is retained as separate because of its distinct morphology. Both C. funicola and C.indicum are epitypified to stabilize the taxonomy. © 2014 The Author(s).