title: A re-evaluation of the genus Myceliophthora (Sordariales, Ascomycota): its segregation into four genera and description of Corynascus fumimontanus sp. nov.
abstract: Based on a number of isolates of Myceliophthora (Chaetomiaceae, Sordariales, Ascomycota) recently isolated from soil samples collected in USA, the taxonomy of the genus was re-evaluated through phylogenetic analyses of sequences from the nuc rDNA internal transcribed spacer region and genes for the second largest subunit of RNA polymerase II and translation elongation factor 1α. Members of Myceliophthora were split into four monophyletic clades strongly supported by molecular and phenotypic data. Such clades correspond with Myceliophthora, now restricted only to the type species of the genus Corynascus, which is re-established with five species, the new monotypic genus Crassicarpon and also the new genus Thermothelomyces (comprising four species). Myceliophthora lutea is mesophilic and a permanently asexual morph compared to the members of the other three mentioned genera, which also are able to sexually reproduce morphs with experimentally proven links to their asexual morphs. The asexual morph of M. lutea is characterized by broadly ellipsoidal, smooth-walled conidia with a wide, truncate base. Crassicarpon thermophilum is thermophilic and heterothallic and produces spherical to cuneiform, smooth-walled conidia and cleistothecial ascomata of smooth-walled, angular cells and ascospores with a germ pore at each end. Corynascus spp. are homothallic and mesophilic and produce spherical, mostly ornamented conidia and cleistothecial ascomata with textura epidermoidea composed of ornamented wall cells, and ascospores with one germ pore at each end. Thermothelomyces spp. are thermophilic, heterothallic and characterized by similar ascomata and conidia as Corynascus spp., but its ascospores exhibit only a single germ pore. A dichotomous key to distinguish Myceliophthora from the other mentioned genera are provided, as well as dichotomous keys to identify the species of Corynascus and Thermothelomyces. A new species, namely Corynascus fumimontanus, characterized by verrucose ascomatal wall cells and irregularly shaped ascospores, is described and illustrated.
authors: Mycology Unit, Medical School and IISPV, Universitat Rovira i Virgili, C/ Sant Llorenç 21, 43201 Reus, Tarragona, Spain.
authors: Yasmina
authors: Y
authors: Marin-Felix
authors: Mycology Unit, Medical School and IISPV, Universitat Rovira i Virgili, C/ Sant Llorenç 21, 43201 Reus, Tarragona, Spain albertomiguel.stchigel@urv.cat.
authors: Alberto M
authors: AM
authors: Stchigel
authors: Illinois Natural History Survey, University of Illinois, 1816 S. Oak St., Champaign, Illinois 61820.
authors: Andrew N
authors: AN
authors: Miller
authors: Mycology Unit, Medical School and IISPV, Universitat Rovira i Virgili, C/ Sant Llorenç 21, 43201 Reus, Tarragona, Spain.
authors: Josep
authors: J
authors: Guarro
authors: Mycology Unit, Medical School and IISPV, Universitat Rovira i Virgili, C/ Sant Llorenç 21, 43201 Reus, Tarragona, Spain.
authors: José F
authors: JF
authors: Cano-Lira
mesh_terms: D001203:Ascomycota / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D004271:DNA, Fungal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012319:RNA Polymerase II / Q000235:genetics; D012988:Soil Microbiology; D020037:Sordariales / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D013172:Spores, Fungal / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D005656:Fungal Proteins; D012319:RNA Polymerase II
keywords: Chaetomiaceae; Crassicarpon; Pezizomycotina; Thermothelomyces; soilborne fungi