New genera and species with chloridium-like morphotype in the Chaetosphaeriales and Vermiculariopsiellales

In this study, we investigated the morphological and genetic variability of selected species belonging to the genus Chloridium sensu lato, some also referred to as chloridium-like asexual morphs and other undescribed morphologically similar fungi. These species do not conform to the revised generic concept and thus necessitate a re-evaluation in terms of taxonomy and phylogeny. The family Chaetosphaeriaceae (Chaetosphaeriales) encompasses a wide range of asexual morphotypes, and among them, the simplest form is represented by Chloridium sect. Chloridium. The morphological simplicity of the Chloridium morphotype has historically led to the amalgamation of numerous unrelated species, thereby creating a heterogeneous genus. By conducting phylogenetic reconstruction of four DNA loci and examining a set of 71 strains, including all available ex-type and other non-type strains as well as holotypes and other herbarium material, we were able to gain new insights into the relationships between these taxa. Phylogenetic analyses revealed that the studied species are distantly related to Chloridium sensu stricto and can be grouped into two orders in the Sordariomycetes. Within the Chaetosphaeriales, they formed nine well-separated genera in four clades, such as Cacumisporium, Caliciastrum gen. nov., Caligospora gen. nov., Capillisphaeria gen. nov., Curvichaeta, Fusichloridium, Geniculoseta gen. nov., Papillospora gen. nov., and Spicatispora gen. nov. We also established Chloridiopsiella gen. nov. and Chloridiopsis gen. nov. in Vermiculariopsiellales. Four new species and eight new combinations are proposed in these genera. Our study provides a clearer understanding of the genus Chloridium, its relationship to other morphologically similar fungi, and a new taxonomic treatment and molecular phylogeny to facilitate their accurate identification and classification in future research. Taxonomic novelties: New genera: Caliciastrum Réblová, Caligospora Réblová, Capillisphaeria Réblová, Chloridiopsiella Réblová, Chloridiopsis Réblová, Geniculoseta Réblová, Papillospora Réblová, Spicatispora Réblová; New species: Caliciastrum bicolor Réblová, Caligospora pannosa Réblová, Chloridiopsis syzygii Réblová, Gongromerizella silvana Réblová; New combinations: Caligospora dilabens (Réblová & W. Gams) Réblová, Capillisphaeria crustacea (Sacc.) Réblová, Chloridiopsiella preussii (W. Gams & Hol.-Jech.) Réblová, Chloridiopsis constrictospora (Crous et al.) Réblová, Geniculoseta preussii (W. Gams & Hol.-Jech.) Réblová, Papillospora hebetiseta (Réblová & W. Gams) Réblová, Spicatispora carpatica (Hol.-Jech. & Révay) Réblová, Spicatispora fennica (P. Karst.) Réblová; Epitypifications (basionyms): Chaetosphaeria dilabens Réblová & W. Gams, Chloridium cylindrosporum W. Gams & Hol.-Jech. Citation: Réblová M, Nekvindová J (2023). New genera and species with chloridium-like morphotype in the Chaetosphaeriales and Vermiculariopsiellales. Studies in Mycology 106: 199-258. doi: 10.3114/sim.2023.106.04.

Diversity and novel lineages of black yeasts in Chaetothyriales from freshwater sediments in Spain

Black yeasts comprise a group of Ascomycota of the order Chaetothyriales with highly variable morphology, a great diversity of ecological niches and life cycles. Despite the ubiquity of these fungi, their diversity in freshwater sediments is still poorly understood. During a survey of culturable Ascomycota from river and stream sediments in various sampling sites in Spain, we obtained 47 isolates of black yeasts by using potato dextrose agar supplemented with cycloheximide. A preliminary morphological study and sequence analyses of the internal transcribed spacer region (ITS) and the large subunit (LSU) of the nuclear rDNA revealed that most of the isolates belonged to the family Herpotrichiellaceae. We have confidently identified 30 isolates representing the following species: Capronia pulcherrima, Cladophialophora emmonsii, Exophiala equina, Exophiala pisciphila, Exophiala radicis, and Phialophora americana. However, we encountered difficulty in assigning 17 cultures to any known species within Chaetothyriales. Combining phenotypic and multi-locus phylogenetic analyses based on the ITS, LSU, β-tubulin (tub2) and translation elongation factor 1-α (tef1-α) gene markers, we propose the new genus Aciculomyces in the Herpotrichiellaceae to accommodate the novel species Aciculomyces restrictus. Other novel species in this family include Cladophialophora denticulata, Cladophialophora heterospora, Cladophialophora irregularis, Exophiala candelabrata, Exophiala dehoogii, Exophiala ramosa, Exophiala verticillata and Phialophora submersa. The new species Cyphellophora spiralis, closely related to Cyphellophora suttonii, is described, and the phylogeny of the genus Anthopsis in the family Cyphellophoraceae is discussed. By utilizing these four markers, we were able to strengthen the phylogenetic resolution and provide more robust taxonomic assessments within the studied group. Our findings indicate that freshwater sediments may serve as a reservoir for intriguing black yeasts, which warrant further investigation to address gaps in phylogenetic relationships, particularly within Herpotrichiellaceae. Citation: Torres-Garcia D, García D, Réblová M, et al. 2023. Diversity and novel lineages of black yeasts in Chaetothyriales from freshwater sediments in Spain. Persoonia 51: 194-228. doi: 10.3767/persoonia.2023.51.05.

Phylogenetic placement of Iodosphaeriaceae (Xylariales, Ascomycota), designation of an epitype for the type species of Iodosphaeria, I. phyllophila, and description of I. foliicola sp. nov

The Iodosphaeriaceae is represented by the single genus, Iodosphaeria, which is composed of nine species with superficial, black, globose ascomata covered with long, flexuous, brown hairs projecting from the ascomata in a stellate fashion, unitunicate asci with an amyloid apical ring or ring lacking and ellipsoidal, ellipsoidal-fusiform or allantoid, hyaline, aseptate ascospores. Members of Iodosphaeria are infrequently found worldwide as saprobes on various hosts and a wide range of substrates. Only three species have been sequenced and included in phylogenetic analyses, but the type species, I. phyllophila, lacks sequence data. In order to stabilize the placement of the genus and family, an epitype for the type species was designated after obtaining ITS sequence data and conducting maximum likelihood and Bayesian phylogenetic analyses. Iodosphaeria foliicola occurring on overwintered Alnus sp. leaves is described as new. Five species in the genus form a well-supported monophyletic group, sister to the Pseudosporidesmiaceae in the Xylariales. Selenosporella-like and/or ceratosporium-like synasexual morphs were experimentally verified or found associated with ascomata of seven of the nine accepted species in the genus. Taxa included and excluded from Iodosphaeria are discussed.

Consolidation of Chloridium: new classification into eight sections with 37 species and reinstatement of the genera Gongromeriza and Psilobotrys

Chloridium is a little-studied group of soil- and wood-inhabiting dematiaceous hyphomycetes that share a rare mode of phialidic conidiogenesis on multiple loci. The genus has historically been divided into three morphological sections, i.e. Chloridium, Gongromeriza, and Psilobotrys. Sexual morphs have been placed in the widely perceived genus Chaetosphaeria, but unlike their asexual counterparts, they show little or no morphological variation. Recent molecular studies have expanded the generic concept to include species defined by a new set of morphological characters, such as the collar-like hyphae, setae, discrete phialides, and penicillately branched conidiophores. The study is based on the consilience of molecular species delimitation methods, phylogenetic analyses, ancestral state reconstruction, morphological hypotheses, and global biogeographic analyses. The multilocus phylogeny demonstrated that the classic concept of Chloridium is polyphyletic, and the original sections are not congeneric. Therefore, we abolish the existing classification and propose to restore the generic status of Gongromeriza and Psilobotrys. We present a new generic concept and define Chloridium as a monophyletic, polythetic genus comprising 37 species distributed in eight sections. In addition, of the taxa earlier referred to Gongromeriza, two have been redisposed to the new genus Gongromerizella. Analysis of published metabarcoding data showed that Chloridium is a common soil fungus representing a significant (0.3 %) proportion of sequence reads in environmental samples deposited in the GlobalFungi database. The analysis also showed that they are typically associated with forest habitats, and their distribution is strongly influenced by climate, which is confirmed by our data on their ability to grow at different temperatures. We demonstrated that Chloridium forms species-specific ranges of distribution, which is rarely documented for microscopic soil fungi. Our study shows the feasibility of using the GlobalFungi database to study the biogeography and ecology of fungi.

The root-symbiotic Rhizoscyphus ericae aggregate and Hyaloscypha (Leotiomycetes) are congeneric: Phylogenetic and experimental evidence

Data mining for a phylogenetic study including the prominent ericoid mycorrhizal fungus Rhizoscyphus ericae revealed nearly identical ITS sequences of the bryophilous Hyaloscypha hepaticicola suggesting they are conspecific. Additional genetic markers and a broader taxonomic sampling furthermore suggested that the sexual Hyaloscypha and the asexual Meliniomyces may be congeneric. In order to further elucidate these issues, type strains of all species traditionally treated as members of the Rhizoscyphus ericae aggregate (REA) and related taxa were subjected to phylogenetic analyses based on ITS, nrLSU, mtSSU, and rpb2 markers to produce comparable datasets while an in vitro re-synthesis experiment was conducted to examine the root-symbiotic potential of H. hepaticicola in the Ericaceae. Phylogenetic evidence demonstrates that sterile root-associated Meliniomyces, sexual Hyaloscypha and Rhizoscyphus, based on R. ericae, are indeed congeneric. To this monophylum also belongs the phialidic dematiaceous hyphomycetes Cadophora finlandica and Chloridium paucisporum. We provide a taxonomic revision of the REA; Meliniomyces and Rhizoscyphus are reduced to synonymy under Hyaloscypha. Pseudaegerita, typified by P. corticalis, an asexual morph of H. spiralis which is a core member of Hyaloscypha, is also transferred to the synonymy of the latter genus. Hyaloscypha melinii is introduced as a new root-symbiotic species from Central Europe. Cadophora finlandica and C. paucisporum are confirmed conspecific, and four new combinations in Hyaloscypha are proposed. Based on phylogenetic analyses, some sexually reproducing species can be attributed to their asexual counterparts for the first time whereas the majority is so far known only in the sexual or asexual state. Hyaloscypha bicolor sporulating in vitro is reported for the first time. Surprisingly, the mycological and mycorrhizal sides of the same coin have never been formally associated, mainly because the sexual and asexual morphs of these fungi have been studied in isolation by different research communities. Evaluating all these aspects allowed us to stabilize the taxonomy of a widespread and ecologically well-studied group of root-associated fungi and to link their various life-styles including saprobes, bryophilous fungi, root endophytes as well as fungi forming ericoid mycorrhizae and ectomycorrhizae.

Phylogenetic classification and generic delineation of Calyptosphaeria gen. nov., Lentomitella, Spadicoides and Torrentispora (Sordariomycetes)

The genus Ceratostomella has a long history of taxonomic confusion. While species with evanescent asci have been transferred to the Microascales and Ophiostomatales, the taxonomic status of species with persistent asci has not been completely resolved. In previous studies using DNA sequence data, cultures and morphology, several Ceratostomella spp. were allocated in 13 genera in the Eurotiomycetes and Sordariomycetes. In our study, the systematics of the remaining Ceratostomella spp. with persistent asci is revisited with new collection data, cultures and phylogeny based on novel DNA sequences from six nuclear loci. Bayesian inference and Maximum Likelihood analyses support the monophyly of several wood-inhabiting species formerly classified in Ceratostomella and other unknown morphologically similar taxa and their division into four genera, i.e. Lentomitella, Spadicoides, Torrentispora and the newly described Calyptosphaeria. This robust clade represents the order Xenospadicoidales in the Sordariomycetidae. Comparative analysis of the ITS2 secondary structure revealed a genetic variation among Lentomitella isolates; 11 species were recognised, of which five are newly introduced and two are new combinations. Other taxonomic novelties include four new species and eight new combinations in Calyptosphaeria, Spadicoides, and Torrentispora. Molecular data suggest that Spadicoides is polyphyletic. The core of the genus is positioned in the Xenospadicoidales; Spadicoides s. str. is experimentally linked with sexual morphs for the first time. Based on DNA sequence data, the monotypic genera Xenospadicoides and Pseudodiplococcium are reduced to synonymy under Spadicoides, while Fusoidispora and Pseudoannulatascus are synonymised with Torrentispora. Members of the Xenospadicoidales inhabit decaying wood in terrestrial and freshwater environments and share a few morphological characters such as the absence of stromatic tissue, ascomata with a cylindrical or rostrate neck, similar anatomies of the ascomatal walls, thin-walled unitunicate asci with a non-amyloid apical annulus, disintegrating paraphyses, usually ellipsoidal to fusiform ascospores and holoblastic-denticulate or tretic conidiogenesis. Revised Ceratostomella spp. with persistent asci are listed and the taxonomic status of each species is re-evaluated based on revision of the holotype and other representative material, published details and available phylogenetic data.

Generic hyper-diversity in Stachybotriaceae

The family Stachybotriaceae was recently introduced to include the genera Myrothecium, Peethambara and Stachybotrys. Members of this family include important plant and human pathogens, as well as several species used in industrial and commercial applications as biodegraders and biocontrol agents. However, the generic boundaries in Stachybotriaceae are still poorly defined, as type material and sequence data are not readily available for taxonomic studies. To address this issue, we performed multi-locus phylogenetic analyses using partial gene sequences of the 28S large subunit (LSU), the internal transcribed spacer regions and intervening 5.8S nrRNA (ITS), the RNA polymerase II second largest subunit (rpb2), calmodulin (cmdA), translation elongation factor 1-alpha (tef1) and β-tubulin (tub2) for all available type and authentic strains. Supported by morphological characters these data resolved 33 genera in the Stachybotriaceae. These included the nine already established genera Albosynnema, Alfaria, Didymostilbe, Myrothecium, Parasarcopodium, Peethambara, Septomyrothecium, Stachybotrys and Xepicula. At the same time the generic names Melanopsamma, Memnoniella and Virgatospora were resurrected. Phylogenetic inference further showed that both the genera Myrothecium and Stachybotrys are polyphyletic resulting in the introduction of 13 new genera with myrothecium-like morphology and eight new genera with stachybotrys-like morphology.

Monilochaetes and allied genera of the Glomerellales, and a reconsideration of families in the Microascales

We examined the phylogenetic relationships of two species that mimic Chaetosphaeria in teleomorph and anamorph morphologies, Chaetosphaeriatulasneorum with a Cylindrotrichum anamorph and Australiasca queenslandica with a Dischloridium anamorph. Four data sets were analysed: a) the internal transcribed spacer region including ITS1, 5.8S rDNA and ITS2 (ITS), b) nc28S (ncLSU) rDNA, c) nc18S (ncSSU) rDNA, and d) a combined data set of ncLSU-ncSSU-RPB2 (ribosomal polymerase B2). The traditional placement of Ch. tulasneorum in the Microascales based on ncLSU sequences is unsupported and Australiasca does not belong to the Chaetosphaeriaceae. Both holomorph species are nested within the Glomerellales. A new genus, Reticulascus, is introduced for Ch. tulasneorum with associated Cylindrotrichum anamorph; another species of Reticulascus and its anamorph in Cylindrotrichum are described as new. The taxonomic structure of the Glomerellales is clarified and the name is validly published. As delimited here, it includes three families, the Glomerellaceae and the newly described Australiascaceae and Reticulascaceae. Based on ITS and ncLSU rDNA sequence analyses, we confirm the synonymy of the anamorph genera Dischloridium with Monilochaetes. Consequently Dischloridium laeënse, type species of the genus, and three related species are transferred to the older genus Monilochaetes. The teleomorph of D. laeënse is described in Australiasca as a new species. The Plectosphaerellaceae, to which the anamorph genus Stachylidium is added, is basal to the Glomerellales in the three-gene phylogeny. Stilbella annulata also belongs to this family and is newly combined in Acrostalagmus. Phylogenetic analyses based on ncLSU, ncSSU, and combined ncLSU-ncSSU-RPB2 sequences clarify family relationships within the Microascales. The family Ceratocystidaceae is validated as a strongly supported monophyletic group consisting of Ceratocystis, Cornuvesica, Thielaviopsis, and the type species of Ambrosiella. The new family Gondwanamycetaceae, a strongly supported sister clade to the Ceratocystidaceae, is introduced for the teleomorph genus Gondwanamyces and its Custingophora anamorphs. Four families are accepted in the Microascales, namely the Ceratocystidaceae, Gondwanamycetaceae, Halosphaeriaceae, and Microascaceae. Because of a suggested affinity of a Faurelina indica isolate to the Microascales, the phylogenetic position of the Chadefaudiellaceae is reevaluated. Based on the results from a separate ncLSU analysis of the Dothideomycetes, Faurelina is excluded from the Microascales and placed in the Pleosporales.

Discovery of the teleomorph of the hyphomycete, Sterigmatobotrys macrocarpa, and epitypification of the genus to holomorphic status

Sterigmatobotrys macrocarpa is a conspicuous, lignicolous, dematiaceous hyphomycete with macronematous, penicillate conidiophores with branches or metulae arising from the apex of the stipe, terminating with cylindrical, elongated conidiogenous cells producing conidia in a holoblastic manner. The discovery of its teleomorph is documented here based on perithecial ascomata associated with fertile conidiophores of S. macrocarpa on a specimen collected in the Czech Republic; an identical anamorph developed from ascospores isolated in axenic culture. The teleomorph is morphologically similar to species of the genera Carpoligna and Chaetosphaeria, especially in its nonstromatic perithecia, hyaline, cylindrical to fusiform ascospores, unitunicate asci with a distinct apical annulus, and tapering paraphyses. Identical perithecia were later observed on a herbarium specimen of S. macrocarpa originating in New Zealand. Sterigmatobotrys includes two species, S. macrocarpa, a taxonomic synonym of the type species, S. elata, and S. uniseptata. Because no teleomorph was described in the protologue of Sterigmatobotrys, we apply Article 59.7 of the International Code of Botanical Nomenclature. We epitypify (teleotypify) both Sterigmatobotrys elata and S. macrocarpa to give the genus holomorphic status, and the name S. macrocarpa is adopted for the holomorph. To evaluate the ordinal and familial affinities of Sterigmatobotrys and its relationships with the morphologically similar genera Carpoligna and Chaetosphaeria, phylogenetic relationships were inferred based on aligned sequences of the large subunit nuclear ribosomal DNA (ncLSU rDNA).