Anamorphic chaetosphaeriaceous fungi from China

Chaetosphaeriaceae is one of the largest families in Sordariomycetes with its members commonly found on decaying leaf, fruit, branch, bark and wood in both terrestrial and submerged environment in nature. This paper reports our research result of diversity, taxonomy and phylogeny of anamorphic Chaetosphaeriaceae in China, which is based on a systematic study with an integrated approach of morphological observation and phylogenetic analysis for a large collection (> 1300 herbarium specimens and 1100 living strains). The family Chaetosphaeriaceae is expanded to accommodate 89 accepted genera, including 22 new genera and 10 newly assigned genera. Most of these genera (except for Chaetosphaeria and several other relatively large genera) are delimitated as monophyletic genera with well-defined diagnostic characters in morphology. The phylogenetic connection of non-phialidic Sporidesmium-like fungi is further confirmed and expanded to 10 different genera. The polyphyletic Codinaea/Dictyochaeta/Tainosphaeria complex is further resolved with a taxonomic framework of 28 monophyletic genera by redelimitation of Codinaea and Dictyochaeta with narrower concept, acceptance of the 16 established genera, and finally introduction of 10 new genera. Chloridium is phylogenetically redefined as monophyletic genus with narrower concept as typified by the type species, but a systematic review in both generic and species level is still needed. For biodiversity of chaetosphaeriaceous fungi, a total of 369 species in 76 genera, including 119 new species, 47 new combinations, and one new name, are documented. The identification keys are provided for most genera, especially the large genera such as Codinaea s. str., Codinaeella, Stilbochaeta, Cryptophiale, Thozetella, Dinemasporium and Pseudolachnella. In addition, ten known species were excluded from the family and reclassified. Systematic revision of several relatively large polyphyletic genera should be conducted in future studies, including Bahusutrabeeja, Ellisembia, Stanjehughesia, Cacumisporium, Chaetosphaeria, Chloridium, Craspedodidymum, Cryptophiale, Cryptophialoidea, Dictyochaetopsis, Minimidochium, and many published species of Codinaea and Dictyochaeta.

Cadophora species from marine glaciers in the Qinghai-Tibet Plateau: an example of unsuspected hidden biodiversity

Large numbers of marine glaciers in the Qinghai-Tibet Plateau are especially sensitive to changes of climate and surface conditions. They have suffered fast accumulation and melting and retreated quickly in recent years. In 2017, we surveyed the cold-adapted fungi in these unique habitats and obtained 1208 fungal strains. Based on preliminary analysis of ITS sequences, 41 isolates belonging to the genus Cadophora were detected. As one of the most frequently encountered genera, the Cadophora isolates were studied in detail. Two phylogenetic trees were constructed: one was based on the partial large subunit nrDNA (LSU) to infer taxonomic placement of our isolates and the other was based on multi-locus sequences of LSU, ITS, TUB and TEF-1α to investigate more exact phylogenetic relationships between Cadophora and allied genera. Combined with morphological characteristics, nine Cadophora species were determined, including seven new to science. Among the new species, only C. inflata produces holoblastic conidia and all the others express phialidic conidiogenesis. All isolates have optimum growth temperature at 20 °C or 25 °C. With more species involved, the currently circumscribed genus became obviously paraphyletic. All members are clustered into two main clades: one clade mainly includes most of the Cadophora species which have phialidic conidiogenesis and we refer to as 'Cadophora s. str.'; the remaining Cadophora species have multiform conidiogenesis and are clustered in the second clade, with members of other genera in Ploettnerulaceae interspersed among the subclades. The results show a high diversity of Cadophora from marine glaciers in the Qinghai-Tibet Plateau and most of them are novel species.

Brassicaceous roots as an unexpected diversity hot-spot of helotialean endophytes

A high number of fungal strains were isolated from roots of Brassicaceae species collected across western and southern Europe, resulting in an unexpectedly rich collection of Cadophora species. These isolates enable us to present a new and comprehensive view of the ecological, morphological, and phylogenetic traits of root-inhabiting members of this helotialean genus. We provide phylogenetic placement of all of our isolates based on a four-gene dataset, analyze their phenotypic traits in relation to their phylogenetic relationships, and infer the potential distribution ranges of the species by sequence comparisons with available databases. We consider seven well supported phylogenetic lineages as species new to science. Six further lineages probably also represent new species but remain undescribed due to the lack of diagnostic morphological characters. Our results show that Cadophora, as currently circumscribed, is paraphyletic and encompasses a broad spectrum of morphologies and lifestyles. Among the new species, only two (C. ferruginea and C. constrictospora) form phialides and conidia typical of Cadophora, three species (C. echinata, C. gamsii and C. variabilis) produce chains of swollen hyphal segments that may function as holoblastic conidia, and one species (C. fascicularis) produces chains of holoblastic ramoconidia and conidia. Ancestral state reconstruction analysis suggests that phialidic conidiogenesis evolved several times in Cadophora s. lat. from a putatively holoblastic common ancestor. Most Cadophora lineages are rare as estimated from the availability of sequence data, in spite of having relatively wide distribution ranges, whereas five lineages may represent endemic relationships given their restricted distributions. Our dataset, probably the most comprehensive available for Cadophora, nevertheless shows knowledge gaps concerning the phylogenetic relationships within this genus and highlights a need for further investigation.

Microbiota in Waterlogged Archaeological Wood: Use of Next-Generation Sequencing to Evaluate the Risk of Biodegradation

Waterlogged archaeological wood (WAW) is considered a precious material, first-hand account of past civilizations. Like any organic material, it is subjected to biodegradative action of microorganisms whose activity could be particularly fast and dangerous during the phases of excavation, storage and restoration. The present work aimed to characterize the microorganisms present in WAW during these tricky periods to evaluate the biological risk it is exposed to. The bacterial and fungal communities inhabiting woods coming from two archaeological sites (Pisa and Naples) were investigated through Next-Generation Sequencing (NGS). High-throughput sequencing of extracted DNA fragments was performed using the reversible terminator-based sequencing chemistry with the Illumina MiSeq platform. The analyses revealed that the two archaeological sites showed distinct richness and biodiversity, as expected. In all the WAWs, the bacterial community harbored mainly Proteobacteria, whereas Bacteroidetes was well represented only in Naples communities and taxa belonging to the phyla Chloroflexi only in the Pisa site. Concerning the fungal community, the two sites were dominated by different phyla: Ascomycota for Naples samples and Basidiomycota for Pisa. Interestingly, most of the identified bacterial and fungal taxa have cellulolytic or ligninolytic ability. These results provide new and useful background information concerning the composition of WAW microbiota and the threat it represents for this precious material.

Arboricolonus simplex gen. et sp. nov. and novelties in Cadophora, Minutiella and Proliferodiscus from Prunus wood in Germany

During a survey on fungi associated with wood necroses of Prunus trees in Germany, strains belonging to the Leotiomycetes and Eurotiomycetes were detected by preliminary analyses of ITS sequences. Multi-locus phylogenetic analyses (LSU, ITS, TUB, EF-1α, depending on genus) of 31 of the 45 strains from Prunus and reference strains revealed several new taxa, including Arboricolonus gen. nov., a new genus in the Helotiales (Leotiomycetes) with a collophorina-like asexual morph. Seven Cadophora species (Helotiales, Leotiomycetes) were treated. The 29 strains from Prunus belonged to five species, of which C. luteo-olivacea and C. novi-eboraci were dominating; C. africana sp. nov., C. prunicola sp. nov. and C. ramosa sp. nov. were revealed as new species. The genus Cadophora was reported from Prunus for the first time. Phialophora bubakii was combined in Cadophora and differentiated from C. obscura, which was resurrected. Asexual morphs of two Proliferodiscus species (Helotiales, Leotiomycetes) were described, including one new species, Pr. ingens sp. nov. Two Minutiella species (Phaeomoniellales, Eurotiomycetes) were detected, including the new species M. pruni-avium sp. nov. Prunus avium and P. domestica are reported as host plants of Minutiella.

Mollisiaceae: An overlooked lineage of diverse endophytes

Mollisia is a taxonomically neglected discomycete genus (Helotiales, Leotiomycetes) of commonly encountered saprotrophs on decaying plant tissues throughout temperate regions. The combination of indistinct morphological characters, more than 700 names in the literature, and lack of reference DNA sequences presents a major challenge when working with Mollisia. Unidentified endophytes, including strains that produced antifungal or antiinsectan secondary metabolites, were isolated from conifer needles in New Brunswick and placed with uncertainty in Phialocephala and Mollisia, necessitating a more comprehensive treatment of these genera. In this study, morphology and multigene phylogenetic analyses were used to explore the taxonomy of Mollisiaceae, including Mollisia, Phialocephala, and related genera, using new field collections, herbarium specimens, and accessioned cultures and sequences. The phylogeny of Mollisiaceae was reconstructed and compared using the nuc internal transcribed spacer rDNA (ITS) barcode and partial sequences of the 28S nuc rDNA (LSU) gene, largest subunit of RNA polymerase II (RPB1), DNA topoisomerase I (TOP1), and the hypothetical protein Lipin/Ned1/Smp2 (LNS2). The results show that endophytism is common throughout the Mollisiaceae lineage in a diverse range of hosts but is infrequently attributed to Mollisia because of a paucity of reference sequences. Generic boundaries within Mollisiaceae are poorly resolved and based on phylogenetic evidence the family included species placed in Acephala, Acidomelania, Barrenia, Bispora, Cheirospora, Cystodendron, Fuscosclera, Hysteronaevia, Loramyces, Mollisia, Neopyrenopeziza, Obtectodiscus, Ombrophila, Patellariopsis, Phialocephala, Pulvinata, Tapesia (=Mollisia), and Trimmatostroma. Taxonomic novelties included the description of five novel Mollisia species and five novel Phialocephala species and the synonymy of Fuscosclera with Phialocephala, Acidomelania with Mollisia, and Loramycetaceae with Mollisiaceae.

A multigene phylogeny toward a new phylogenetic classification of Leotiomycetes

Fungi in the class Leotiomycetes are ecologically diverse, including mycorrhizas, endophytes of roots and leaves, plant pathogens, aquatic and aero-aquatic hyphomycetes, mammalian pathogens, and saprobes. These fungi are commonly detected in cultures from diseased tissue and from environmental DNA extracts. The identification of specimens from such character-poor samples increasingly relies on DNA sequencing. However, the current classification of Leotiomycetes is still largely based on morphologically defined taxa, especially at higher taxonomic levels. Consequently, the formal Leotiomycetes classification is frequently poorly congruent with the relationships suggested by DNA sequencing studies. Previous class-wide phylogenies of Leotiomycetes have been based on ribosomal DNA markers, with most of the published multi-gene studies being focussed on particular genera or families. In this paper we collate data available from specimens representing both sexual and asexual morphs from across the genetic breadth of the class, with a focus on generic type species, to present a phylogeny based on up to 15 concatenated genes across 279 specimens. Included in the dataset are genes that were extracted from 72 of the genomes available for the class, including 10 new genomes released with this study. To test the statistical support for the deepest branches in the phylogeny, an additional phylogeny based on 3156 genes from 51 selected genomes is also presented. To fill some of the taxonomic gaps in the 15-gene phylogeny, we further present an ITS gene tree, particularly targeting ex-type specimens of generic type species. A small number of novel taxa are proposed: Marthamycetales ord. nov., and Drepanopezizaceae and Mniaeciaceae fams. nov. The formal taxonomic changes are limited in part because of the ad hoc nature of taxon and specimen selection, based purely on the availability of data. The phylogeny constitutes a framework for enabling future taxonomically targeted studies using deliberate specimen selection. Such studies will ideally include designation of epitypes for the type species of those genera for which DNA is not able to be extracted from the original type specimen, and consideration of morphological characters whenever genetically defined clades are recognized as formal taxa within a classification.

A metabolite of endophytic fungus Cadophora orchidicola from Kalimeris indica serves as a potential fungicide and TLR4 agonist

AIM

To investigate the bioactive metabolite of endophytic fungus from Kalimeris indica.

METHODS AND RESULTS

A strain ZJLQ336 was separated from the leaves of K. indica. It was identified as Cadophora orchidicola based on the phylogenetic analysis of ITS-rDNA sequences. From the fermentation broth a metabolite cercosporamide (compound 1) was isolated, and its structure was determined by spectroscopic analysis. Additionally, this compound was subjected to bioactivity assays, including antifungal activity against seven plant pathogenic fungi, as well as its potential immunoregulatory effects on HEK-BLUE™-hTLR4 cells, splenocytes and macrophages. The results showed that cercosporamide had strong growth inhibition against five common plant pathogenic fungi, including Pestalotia diospyri, Botrytis cinerea, Fusarium oxysporum, Sclerotium rolfsii and Penicillum digitatum with EC₅₀ values of 5·29 × 10^-3 , 0·61, 0·93, 2·89 and 6·7 μg ml^-1 respectively. Among which S. rolfsii was one of the main pathogens in K. indica. Moreover, cercosporamide not only significantly stimulated TLR4 activation, splenocyte proliferation and production of cytokines, IFN-γ and TNF-α, but also up-regulated the production of TNF-α and NO in RAW264.7 macrophages clearly.

CONCLUSIONS

This is the first report of endophytic C. orchidicola from K. indica and its metabolite cercosporamide. The results of pharmacological tests highlight the potential fungicide and TLR4 agonist of cercosporamide.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study indicates endophytic fungi are good resources for natural bioactive metabolites. It also suggests that cercosporamide is a potential fungicide and TLR4 agonist.

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.

Cadophora margaritata sp. nov. and other fungi associated with the longhorn beetles Anoplophora glabripennis and Saperda carcharias in Finland

Symbiosis with microbes is crucial for survival and development of wood-inhabiting longhorn beetles (Coleoptera: Cerambycidae). Thus, knowledge of the endemic fungal associates of insects would facilitate risk assessment in cases where a new invasive pest occupies the same ecological niche. However, the diversity of fungi associated with insects remains poorly understood. The aim of this study was to investigate fungi associated with the native large poplar longhorn beetle (Saperda carcharias) and the recently introduced Asian longhorn beetle (Anoplophora glabripennis) infesting hardwood trees in Finland. We studied the cultivable fungal associates obtained from Populus tremula colonised by S. carcharias, and Betula pendula and Salix caprea infested by A. glabripennis, and compared these to the samples collected from intact wood material. This study detected a number of plant pathogenic and saprotrophic fungi, and species with known potential for enzymatic degradation of wood components. Phylogenetic analyses of the most commonly encountered fungi isolated from the longhorn beetles revealed an association with fungi residing in the Cadophora-Mollisia species complex. A commonly encountered fungus was Cadophora spadicis, a recently described fungus associated with wood-decay. In addition, a novel species of Cadophora, for which the name Cadophora margaritata sp. nov. is provided, was isolated from the colonised wood.

Sexual and asexual states of some endophytic Phialocephala species of Picea

Unidentified DNA sequences in isolation-based or culture-free studies of conifer endophytes are a persistent problem that requires a field approach to resolve. An investigation of foliar endophytes of Picea glauca, P. mariana, P. rubens and Pinus strobus in eastern Canada, using a combined field, morphological, cultural and DNA sequencing approach, resulted in the frequent isolation of Phialocephala spp. and the first verified discovery of their mollisia-like sexual states in the field. Phialocephala scopiformis and Ph. piceae were the most frequent species isolated as endophytes from healthy conifer needles. Corresponding Mollisia or mollisioid sexual states for Ph. scopiformis, Ph. piceae and several undescribed species in a clade containing Ph. dimorphospora were collected in the sampling area and characterized by analysis of the nuc internal transcribed spacer rDNA (ITS) and gene for the largest subunit of RNA polymerase II (RPB1) loci. Four novel species and one new combination in a clade containing Ph. dimorphospora, the type of Phialocephala, are presented, accompanied by descriptions of apothecia and previously undocumented synanamorphs. An epitype culture and corresponding reference sequences for Phialocephala dimorphospora are proposed. The resulting ITS barcodes linked with robust taxonomic species concepts are an important resource for future research on forest ecosystems and endophytes.

Cadophora species associated with wood-decay of grapevine in North America

Cadophora species are reported from grapevine (Vitis vinifera L.) in California, South Africa, Spain, Uruguay, and Canada. Frequent isolation from vines co-infected with the Esca pathogens (Togninia minima and Phaeomoniella chlamydospora), and confirmation of its ability to cause wood lesions/discoloration in pathogenicity tests, suggest that C. luteo-olivacea is part of the trunk pathogen complex. In North America, little is known regarding the diversity, geographic distribution, and roles of Cadophora species as trunk pathogens. Accordingly, we characterized 37 Cadophora isolates from ten US states and two Canadian provinces, based on molecular and morphological comparisons, and pathogenicity. Phylogenetic analysis of three loci (ITS, translation elongation factor 1-alpha (TEF1-α) and beta-tubulin (BT)) distinguished two known species (C. luteo-olivacea and Cadophora melinii) and three newly-described species (Cadophora orientoamericana, Cadophora novi-eboraci, and Cadophora spadicis). C. orientoamericana, C. novi-eboraci, and C. spadicis were restricted to the northeastern US, whereas C. luteo-olivacea was only recovered from California. C. melinii was present in California and Ontario, Canada. Morphological characterization was less informative, due to significant overlap in dimensions of conidia, hyphae, conidiophores, and conidiogenous cells. Pathogenicity tests confirmed the presence of wood lesions after 24 m, suggesting that Cadophora species may have a role as grapevine trunk pathogens.

Acidomelania panicicola gen. et sp. nov. from switchgrass roots in acidic New Jersey pine barrens

A new genus, Acidomelania, is described based on molecular phylogenetic analyses and ecological and morphological characters. Isolated from switchgrass roots in acidic and oligotrophic New Jersey pine barrens in this study, Acidomelania likely has a global distribution because its internal transcribed spacer (ITS) sequence has high similarity with a number of GenBank sequences resulted from various ecological studies. Apparently these samples all were from roots of plants that lived in acidic, nutrient-poor environments. Phylogenetic analyses based on ITS, LSU and ACT sequence data strongly supported the fact that Acidomelania isolates formed a monophyletic clade in Helotiales, distinct from any known taxa. Phylogenetically Acidomelania is closely related to Loramyces, Mollisia and Phialocephala fortinii, Acephala applanata species complex (PAC), the dark septate endophytes. Acidomelania also can be distinguished from Loramyces and Mollisia by its association with living grass roots. While taxa in PAC also are root endophytes, they have more complex phialid arrangement than Acidomelania. Results from this work will facilitate ecological and evolutionary studies on root-associated fungi.

Recommendations on generic names competing for use in Leotiomycetes (Ascomycota)

In advancing to one scientific name for fungi, this paper treats genera competing for use in the phylogenetically defined class Leotiomycetes except for genera of Erysiphales. Two groups traditionally included in the so-called "inoperculate discomycetes" have been excluded from this class and are also not included here, specifically Geoglossomycetes and Orbiliomycetes. A recommendation is made about the generic name to use in cases in which two or more generic names are synonyms or taxonomically congruent along with the rationale for the recommendation. In some cases the recommended generic name does not have priority or is based on an asexual type species, thus needs to be protected and ultimately approved according to Art. 57.2 of the International Code of Nomenclature for algae, fungi and plants (ICN). A table is presented listing all competing generic names and their type species noting the recommended generic name. New combinations are introduced for the oldest epithet in the recommended genus including Ascocalyx berenice, Ascoconidium purpurascens, Ascocoryne albida, A. trichophora, Blumeriella filipendulae, B. ceanothi, Botrytis arachidis, B. fritillariae-pallidoflori, Calloria urticae, Calycellina aspera, Dematioscypha delicata, Dermea abietinum, D. boycei, D. stellata, Diplocarpon alpestre, D. fragariae, Godroniopsis peckii, Grovesinia moricola, Heterosphaera sublineolata, Hyphodiscus brachyconium, H. brevicollaris, H. luxurians, Leptotrochila campanulae, Monilinia polystroma, Neofabraea actinidae, N. citricarpa, N. vagabunda, Oculimacula aestiva, O. anguioides, Pezicula brunnea, P. californiae, P. cornina, P. diversispora, P. ericae, P. melanogena, P. querciphila, P. radicicola, P. rhizophila, Phialocephala piceae, Pilidium lythri, Rhabdocline laricis, Streptotinia streptothrix, Symphyosirinia parasitica, S. rosea, Unguiculariopsis caespitosa, and Vibrissea laxa.