Corylomyces: a new genus of Sordariales from plant debris in France

The new genus Corylomyces, isolated from the surface of a hazelnut (Corylus avellana) in the French Pyrenees, is described, illustrated and compared with morphologically similar taxa. It is characterised by tomentose, ostiolate ascomata possessing long necks composed of erect to sinuose hairs, and one- or two-celled, opaque, lunate to reniform ascospores. Analyses of the SSU and LSU fragments rDNA gene sequences support its placement in the Lasiosphaeriaceae (Sordariales).     

Chaetosphaeria tortuosa, the newly discovered teleomorph of Menispora tortuosa, with a key to known Menispora species

Chaetosphaeria tortuosa is described as the newly discovered teleomorph of Menispora tortuosa, based on specimens from Canada and the Czech Republic, and single spore isolations from both morphs. The fungus produces superficial, more or less globose, papillate, dark brown to black smooth perithecia (200–)220–250 × (220–)230–260 μm. The asci are unitunicate, 8-spored, cylindrical-fusiform, (110–)120–133(–145) × 12–14 with a distinct apical, nonamyloid annulus 1–1.5 μm high, 3.5–4 μm wide. The ascospores are fusiform, 19–24 × 5–6 μm, hyaline, 3-septate, smooth, and 2-seriate in the ascus. The morphology of the teleomorph and anamorph are similar to that of C. ovoidea (anamorph: M. glauca), differing in dimensions of asci and ascospores, and in the disposition and morphology of the phialides of the anamorphs. The generic concept and phylogeny of Menispora is briefly discussed, and a key to the 11 species currently accepted in the genus is provided.     

Hypocrella panamensis sp. nov. (Clavicipitaceae, Hypocreales): a new species infecting scale insects on Piper carrilloanum in Panama

A new species, Hypocrella panamensis, is described from collections and cultures obtained on Barro Colorado Island, Panama. In order to aid in placement of this fungus, phylogenetic analyses were conducted using LSU (rDNA) sequences. Hypocrella panamensis is characterized by possessing pulvinate stromata with a Lecanicillium-like anamorphic state and superficial perithecia. Hypocrella panamensis consistently grouped in a clade containing Hypocrella nectrioides, H. phyllogena, and H. africana (100 % PP). Most species of Hypocrella possess Aschersonia or Hirsutella anamorphs. Hypocrella panamensis is unique in the genus Hypocrella in possession of a Lecanicillium-like anamorphic state. In its biological habit Hypocrella panamensis is similar to other species in Hypocrella in that it infects and degrades the scale insect, then grows superficially on nutrients that emerge to the plant surface through the stylet wound.     

Trichosporon insectorum sp. nov., a new anamorphic basidiomycetous killer yeast

Three killer yeasts, isolated from the gut of insects in Panama and artisanal cheese in Brazil, were shown to be related to the Ovoides clade of the genus Trichosporon. Sequencing of the D1/D2 region of the LSU rDNA and physiological characterization revealed a distinct taxonomic position in relation to known species of the genus. Conspecificity of the three killer isolates was reinforced by similar M13 fingerprinting and killer profiles. We propose a new species in this genus: Trichosporon insectorum. The type strain is CBS 10422^T (syn. NRRL Y-48120). This anamorphic species produces arthroconidia but not appressoria, and its killer character seems to be associated with dsRNA.     

A new species of Phaeohelotium from Nothofagus forests in Argentina and Chile, with a key to the Southern Hemisphere species

Phaeohelotium nothofagi, sp.nov., found on fallen wood and leaves of Nothofagus dombeyi, is described and illustrated. The fungus is characterized by pale yellow discs, and fumose ascospores with asperulate walls. A key with distributional data for the five species of the genus now known in the Southern Hemisphere is provided.     

A new fungal genus, Teracosphaeria, with a phialophora-like anamorph (Sordariomycetes, Ascomycota)

The new genus and species Teracosphaeria petroica is described for a perithecial ascomycete and its anamorph occurring on decayed wood collected in New Zealand. The fungus produces immersed, non-stromatic ceratosphaeria-like perithecia in nature, with hyaline, septate ascospores produced in unitunicate, non-amyloid asci. The anamorph produced in vitro is phialophora-like with lightly pigmented phialides terminating in flaring, deep collarettes that are often noticeably brown with conspicuous periclinal thickening. Phylogenetic analysis of LSU rDNA sequence data indicates that this fungus is distinct from morphologically similar fungi classified in the Chaetosphaeriales, the Trichosphaeriales or the Magnaporthaceae. It forms a monophyletic group with recently described, chaetosphaeria-like ascomycetes, such as the pyrenomycete genus Mirannulata, and shows affinity with the anamorphic species Dictyochaeta cylindrospora. The usefulness of describing anamorph genera for morphologically reduced anamorphs, when anamorph characteristics are actually part of the holomorph diagnosis, is discussed. An apparently contradictory example of the so-called Cordana and Pseudobotrytis anamorphs of Porosphaerella spp. is also discussed.     

A beauvericin hot spot in the genus Isaria

Beauvericin is a naturally occurring cyclohexadepsipeptide originally described from Beauveria bassiana but also reported from several Fusarium species as well as members of the genus Isaria. Twenty-six isolates of Isaria species and its Cordyceps teleomorph, and ten taxonomically close strains including Beauveria, Nomuraea and Paecilomyces species were sequenced and tested for beauvericin production. Trees using ITS rDNA and β-tubulin sequence data were constructed and used to infer the phylogenetic distribution of beauvericin production. A group comprising Isaria tenuipes and its known teleomorph Cordyceps takaomontana, Isaria cicadae and its Cordyceps teleomorph, Isaria japonica and Isaria fumosorosea, showed positive beauvericin production which correlated well with combined ITS rDNA and β-tubulin phylogenies. The results suggested that beauvericin can serve as a chemotaxonomic marker for these limited species of the I. tenuipes complex.     

Morphology and development of Nigrosabulum globosum, a cleistothecial coprophile in the Bionectriaceae (Hypocreales)

Recent DNA sequence analyses indicated that Nigrosabulum globosum is a cleistothecial representative of the Bionectriaceae in the Hypocreales, but morphological characters supporting this relationship are unknown. Using light and electron microscopy we followed the development of the ascomata of this species, from the formation of gametangia through to the development of mature ascospores, and observed a series of characters that confirmed its hypocrealean affinities. These included the formation of a gel-filled centrum during early stages of ascoma development, the subsequent appearance of hyaline peridial tissue enclosed within a layer we interpret as representing a melanized uniloculate stroma, apically derived paraphyses, and an ascogenous system that gives rise to asci that were both cylindrical to clavate and globose. Ascospores, previously reported to be smooth, were ornamented with a honeycomb-like reticulum and were able to germinate within the ascoma. The carbonaceous outer (stromatic) walls of the mature, grit-like cleistothecia indicate possible resistance to UV radiation and desiccation. Furthermore, the complement of germinated ascospores would enable mature ascomata to function as propagules that could quickly initiate new growth when transferred to fresh substrate. Our reexamination of N. globosum also provides data that support the hypothesized close relationship with other bionectriaceous, cleistothecial coprophiles, i.e., species of Hapsidospora, and Bulbithecium in particular.     

The phylogenetic placement of Ostropales within Lecanoromycetes (Ascomycota) revisited

Results of molecular studies regarding the phylogenetic placement of the order Ostropales and related taxa within Lecanoromycetes were thus far inconclusive. Some analyses placed the order as sister to the rest of Lecanoromycetes, while others inferred a position nested within Lecanoromycetes. We assembled a data set of 101 species including sequences from nuLSU rDNA, mtSSU rDNA, and the nuclear protein-coding RPB1 for each species to examine the cause of incongruencies in previously published phylogenies. MP, minimum evolution, and Bayesian analyses were performed using the combined three-region data set and the single-gene data sets. The position of Ostropales nested in Lecanoromycetes is confirmed in all single-gene and concatenated analyses, and a placement as sister to the rest of Lecanoromycetes is significantly rejected using two independent methods of alternative topology testing. Acarosporales and related taxa (Acarosporaceae group) are basal in Lecanoromycetes. However, if the these basal taxa are excluded from the analyses, Ostropales appear to be sister to the rest of Lecanoromycetes, suggesting different ingroup rooting as the cause for deviating topologies in previously published phylogenies.     

Natural variation of ascospore and conidial germination by Fusarium verticillioides and other Fusarium species

Fusarium verticillioides and other Fusarium species were examined for their spore germination phenotypes. In general, germinating spores of F. verticillioides formed germ tubes that immediately penetrated into agar. Such invasive germination was the predominant growth phenotype among 22 examined field isolates of F. verticillioides from a broad range hosts and locations. However, two of the field isolates were unique in that they formed conidial germ tubes and hyphae that grew along the surface of agar before penetration eventually occurred. Conidia of 22 other Fusarium species were assessed for their germination phenotypes, and only some strains of F. annulatum, F. fujikuroi, F. globosum, F. nygamai, and F. pseudoanthophilum had the surface germination phenotype (21 % of the strains assessed). Sexual crosses and segregation analyses involving one of the F. verticillioides surface germination strains, NRRL 25059, indicated a single locus, designated SIG1 (surface vs. invasive germination), controlled the germ tube growth phenotypes exhibited by both conidia and ascospores. Perfect correlation was observed between an ascospore germination phenotype and the germination phenotype of the conidia produced from the resulting ascospore-derived colony. Recombination data suggested SIG1 was linked (7 % recombination frequency) to FPH1, a recently described locus necessary for enteroblastic conidiogenesis. Corn seedling blight assays indicated surface germinating strains of F. verticillioides were less virulent than invasively germinating strains. Assays also indicated pathogenicity segregated independently of the FPH1 locus. Invasive germination is proposed as the dominant form of spore germination among Fusarium species. Furthermore, conidia were not necessary for corn seedling disease development, but invasive germination may have enhanced the virulence of conidiating strains.     

A polysaccharide from Lichina pygmaea and L. confinis supports the recognition of Lichinomycetes

The lichen-forming order Lichinales, generally characterized by prototunicate asci and the development of thalli with cyanobacteria, has recently been recognized as a separate class of ascomycetes, Lichinomycetes, as a result of molecular phylogenetic studies. As alkali and water-soluble (F1SS) polysaccharides reflect phylogeny in other ascomycetes, a polysaccharide from Lichina pygmaea and L. confinis was purified and characterized to investigate whether these F1SS compounds in the Lichinomycetes were distinctive. Nuclear magnetic resonance (NMR) spectroscopy and chemical analyses revealed this as a galactomannan comprising a repeating unit consisting of an α-(1→6)-mannan backbone, mainly substituted by single α-galactofuranose residues at the O-2- or the O-2,4- positions linked to a small mannan core. With the exception of the trisubstituted mannopyranose residues previously described in polysaccharides from other lichens belonging to orders now placed in Lecanoromycetes, the structure of this galactomannan most closely resembles those found in several members of the Onygenales in Eurotiomycetes. Our polysaccharide data support molecular studies showing that Lichina species are remote from Lecanoromycetes as the galactofuranose residues are in the α-configuration. That the Lichinomycetes were part of an ancestral lichenized group can not be established from the present data because the extracted polysaccharide does not have the galactofuranose residue in the β configuration; however, the data does suggest that an ancestor of the Lichinomycetes contained a mannan and was part of an early radiation in the ascomycetes.     

The type species of Apiognomonia, A. veneta, with its Discula anamorph is distinct from A. errabunda

Species of Apiognomonia with their Discula anamorphic states in the Gnomoniaceae, Diaporthales, are known throughout the temperate Northern Hemisphere and cause diseases such as sycamore or plane tree anthracnose. The genus Apiognomonia was described based on A. veneta as the type species; however, there has been disagreement about whether or not A. veneta is a synonym of A. errabunda. Using morphological, ecological, and DNA sequence data we conclude that A. errabunda and A. veneta are different species, although very closely related; thus, A. veneta is the correct name for the type species of Apiognomonia. This conclusion is based on a combined analysis of sequences from the ITS regions of nuclear rDNA for 51 isolates from host plants of eight genera and intron regions from actin, calmodulin and translation elongation factor 1-alpha for over 25 isolates. The type species of the genus Discula is D. nervisequa, the earliest available epithet for D. platani, the lectotype of Discula. D. nervisequa is the anamorph of A. veneta. Based on an examination of the type specimen, we determined that the commonly used name for the anamorph of A. errabunda, D. umbrinella, refers to another species. A. veneta and A. errabunda including their anamorphs are described and illustrated. An account of all synonyms and excluded synonyms is presented.     

Accelerated nrDNA evolution and profound AT bias in the medicinal fungus Cordyceps sinensis

Cordyceps sinensis is a reputed medicinal fungus growing parasitically on buried larvae of ghost moths in Asian high-altitude grassland ecosystems. We have analysed the intraspecific ITS nrDNA (ITS1, 5.8S gene, ITS2) variation among 71 sequences of C. sinensis available in EMBL/Genbank. The ITS sequences, submitted to Bayesian ML analyses, were distributed into five groups, referred to as A–E. Nine of the sequences (groups D and E) grouped with distantly related hypocrealean/clavicipitalean taxa and are interpreted as sequences erroneously accessioned under wrong taxon names. The remaining 62 sequences constituted three highly supported clades (groups A–C), that may represent cryptic (phylogenetic) species currently ascribed to C. sinensis. A remarkably high sequence divergence occurred in the 5.8S gene between the three groups. Sequences of groups B and C showed accelerated substitution rates and high AT nucleotide bias. We hypothesize that the accelerated evolution and AT bias have been caused by a shift in life historical attributes or ecology. We also suggest that the recorded differences in medicinal effects among C. sinensis populations may be attributed to the existence of genetically differentiated chemotypes in this morphotaxon.     

Cystobasidiopsis nirenbergiae, a new agaricostilbomycete (Pucciniomycotina)

A new genus, Cystobasidiopsis, and a new species, Cystobasidiopsis nirenbergiae, are described for a fungus isolated from an arable loess soil in Ahlum near Braunschweig, Niedersachsen, Germany. An integrated analysis of morphological, ecological, ultrastructural and molecular data indicates that the new species belongs to the Chionosphaeraceae within the Agaricostilbales. Relevant characteristics of the new species are discussed and compared with those of related taxa.     

New species of Phaeoramularia, Pseudocercospora and Stenella from Western Ghats of India

Four new species of the hyphomycete genera Phaeoramularia viz. Ph. caesalpinae, Pseudocercospora viz., Ps. tiliacearum, Stenella, viz. S. argyreiae and S. grewiae occurring on Caesalpinia bonducella Fleming (Caesalpiniaceae), Grewia sp. (Tiliaceae), Argyrea sp. Lour (Convolvulaceae) and Grewia sp. L. (Tiliaceae), respectively are described and illustrated here. All these fungi were collected from Western Ghats of India.     

The arachiform vacuolar body: an overlooked shared character in the ascospores of a large monophyletic group within Parmeliaceae (Xanthoparmelia clade, Lecanorales)

Sections of apothecia were used to study the internal morphology of ascospores in the largest monophyletic clade within Parmeliaceae composed of Xanthoparmelia and related genera. The results were compared with fertile representative species of most other parmelioid clades. All the Xanthoparmelia species had spores with a single smooth vacuole, which was peanut-shaped, with different degrees of constriction in the equatorial plane. This differs from the ellipsoid vacuole of other parmelioids. In the Xanthoparmelia clade, sexual reproduction seems much more common than in other parmelioids. Thus, we suggest that the presence of this unique spore morphology might contribute to the evolutionary success of this monophyletic group. Further, the discovery of this useful ascospore character demonstrates that detailed ascospore morphological studies significantly enhance molecular phylogenetic analyses. Ascospore features may be more taxonomically significant in Parmeliaceae than hitherto considered.