Neonectria bordenii sp. nov., a potential symbiote of the alder bark beetle, and its detection by quantitative PCR.

A taxonomically comprehensive perspective on the fungal associates of bark beetles (Coleoptera: Curculionidae: Scolytinae), and powerful molecular tools for detection of these fungi, are imperative to understanding bark beetle impacts on forest ecosystems. The most common filamentous fungi living alongside bark beetles in infested trees are ophiostomatoids (Ascomycota: Ophiostomatales and Microascales), yet an undescribed species of Neonectria (Neonectria sp. nov.; Ascomycota: Hypocreales) was recently identified cohabitating with the alder bark beetle, Alniphagus aspericollis, in red alder, Alnus rubra. The hardwood-infesting alder bark beetle is found throughout the range of its red alder host in the Pacific Coast region of North America and is associated with Neonectria sp. nov. in southwestern British Columbia, Canada. The aim of this study was to describe and name Neonectria sp. nov. and to develop a quantitative PCR (qPCR) assay to enable rapid detection of Neonectria sp. nov. from individual adult alder bark beetles and to define the distribution of the fungus. Neonectria sp. nov. was phylogenetically and morphologically determined to represent a distinct species closely related to N. ditissima and is described herein as Neonectria bordenii sp. nov. Neonectria bordenii was reliably detected from individual whole-beetle DNA extractions using a probe-based qPCR assay targeting multi-copy internal transcribed spacers (ITS) of nuclear ribosomal DNA. The qPCR assay amplified the fungus from 87.8 % (36/41) of individual alder bark beetle samples and was highly sensitive to N. bordenii, with a lower limit of detection of 1 × 10-6 ng/µL of culture DNA (or ~262 genome copies). Application of the qPCR assay developed in this study will expedite future research evaluating N. bordenii as a potential symbiote of the alder bark beetle. Citation: Wertman DL, Tanney JB, Hamelin RC, Carroll AL (2024). Neonectria bordenii sp. nov., a potential symbiote of the alder bark beetle, and its detection by quantitative PCR. Fungal Systematics and Evolution 13: 15-28. doi: 10.3114/fuse.2024.13.02.

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.

Cones, needles and wood: Micraspis (Micraspidaceae, Micraspidales fam. et ord. nov.) speciation segregates by host plant tissues.

Micraspis acicola was described more than 50 years ago to accommodate a phacidium-like fungus that caused a foliar disease of Picea mariana. After its publication, two more species were added, M. strobilina and M. tetraspora, all of them growing on Pinaceae in the Northern Hemisphere, but each species occupying a unique type of host tissue (needles, cones or wood). Micraspis is considered to be a member of class Leotiomycetes, but was originally placed in Phacidiaceae (Phacidiales), later transferred to Helotiaceae (Helotiales) and recently returned to Phacidiales but in a different family (Tympanidaceae). The genus remains poorly sampled, and hence poorly understood both taxonomically and ecologically. Here, we use morphology, cultures and sequences to provide insights into its systematic position in Leotiomycetes and its ecology. Our results show that the genus should not be included in Tympanidaceae or Phacidiaceae, and support the erection of a new family and order with a unique combination of morphological features supported by molecular data.

Tryblidiopsis magnesii sp. nov. from Picea glauca in Eastern Canada.

Tryblidiopsis pinastri (Leotiomycetes, Rhytismatales) was described from Picea abies in Europe and was also thought to occur on North American Picea. However, previously published sequences of Picea foliar endophytes from Eastern Canada suggested the presence of at least two cryptic Tryblidiopsis species, distinct from T. pinastri and other known species. Our subsequent sampling of Tryblidiopsis ascomata from dead attached Picea glauca branches resulted in the collection of a putatively undescribed species previously isolated as a P. glauca endophyte. Morphological evidence combined with phylogenetic analyses based on nuclear ribosomal internal transcribed spacer (ITS) and large subunit ribosomal (LSU) DNA sequences support the distinctiveness of this species, described here as T. magnesii.

Aspergillus subgenus Polypaecilum from the built environment.

Xerophilic fungi, especially Aspergillus species, are prevalent in the built environment. In this study, we employed a combined culture-independent (454-pyrosequencing) and culture-dependent (dilution-to-extinction) approach to investigate the mycobiota of indoor dust collected from 93 buildings in 12 countries worldwide. High and low water activity (aw) media were used to capture mesophile and xerophile biodiversity, resulting in the isolation of approximately 9 000 strains. Among these, 340 strains representing seven putative species in Aspergillus subgenus Polypaecilum were isolated, mostly from lowered aw media, and tentatively identified based on colony morphology and internal transcribed spacer rDNA region (ITS) barcodes. Further morphological study and phylogenetic analyses using sequences of ITS, ß-tubulin (BenA), calmodulin (CaM), RNA polymerase II second largest subunit (RPB2), DNA topoisomerase 1 (TOP1), and a pre-mRNA processing protein homolog (TSR1) confirmed the isolation of seven species of subgenus Polypaecilum, including five novel species: A. baarnensis, A. keratitidis, A. kalimae sp. nov., A. noonimiae sp. nov., A. thailandensis sp. nov., A. waynelawii sp. nov., and A. whitfieldii sp. nov. Pyrosequencing detected six of the seven species isolated from house dust, as well as one additional species absent from the cultures isolated, and three clades representing potentially undescribed species. Species were typically found in house dust from subtropical and tropical climates, often in close proximity to the ocean or sea. The presence of subgenus Polypaecilum, a recently described clade of xerophilic/xerotolerant, halotolerant/halophilic, and potentially zoopathogenic species, within the built environment is noteworthy.

Aspergillus, Penicillium and Talaromyces isolated from house dust samples collected around the world.

As part of a worldwide survey of the indoor mycobiota, dust was collected from nine countries. Analyses of dust samples included the culture-dependent dilution-to-extinction method and the culture-independent 454-pyrosequencing. Of the 7 904 isolates, 2 717 isolates were identified as belonging to Aspergillus, Penicillium and Talaromyces. The aim of this study was to identify isolates to species level and describe the new species found. Secondly, we wanted to create a reliable reference sequence database to be used for next-generation sequencing projects. Isolates represented 59 Aspergillus species, including eight undescribed species, 49 Penicillium species of which seven were undescribed and 18 Talaromyces species including three described here as new. In total, 568 ITS barcodes were generated, and 391 ß-tubulin and 507 calmodulin sequences, which serve as alternative identification markers.

Phylogeny, identification and nomenclature of the genus Aspergillus.

Aspergillus comprises a diverse group of species based on morphological, physiological and phylogenetic characters, which significantly impact biotechnology, food production, indoor environments and human health. Aspergillus was traditionally associated with nine teleomorph genera, but phylogenetic data suggest that together with genera such as Polypaecilum, Phialosimplex, Dichotomomyces and Cristaspora, Aspergillus forms a monophyletic clade closely related to Penicillium. Changes in the International Code of Nomenclature for algae, fungi and plants resulted in the move to one name per species, meaning that a decision had to be made whether to keep Aspergillus as one big genus or to split it into several smaller genera. The International Commission of Penicillium and Aspergillus decided to keep Aspergillus instead of using smaller genera. In this paper, we present the arguments for this decision. We introduce new combinations for accepted species presently lacking an Aspergillus name and provide an updated accepted species list for the genus, now containing 339 species. To add to the scientific value of the list, we include information about living ex-type culture collection numbers and GenBank accession numbers for available representative ITS, calmodulin, ß-tubulin and RPB2 sequences. In addition, we recommend a standard working technique for Aspergillus and propose calmodulin as a secondary identification marker.

Fungal Planet description sheets: 128-153.

Novel species of microfungi described in the present study include the following from Australia: Catenulostroma corymbiae from Corymbia, Devriesia stirlingiae from Stirlingia, Penidiella carpentariae from Carpentaria, Phaeococcomyces eucalypti from Eucalyptus, Phialophora livistonae from Livistona, Phyllosticta aristolochiicola from Aristolochia, Clitopilus austroprunulus on sclerophyll forest litter of Eucalyptus regnans and Toxicocladosporium posoqueriae from Posoqueria. Several species are also described from South Africa, namely: Ceramothyrium podocarpi from Podocarpus, Cercospora chrysanthemoides from Chrysanthemoides, Devriesia shakazului from Aloe, Penidiella drakensbergensis from Protea, Strelitziana cliviae from Clivia and Zasmidium syzygii from Syzygium. Other species include Bipolaris microstegii from Microstegium and Synchaetomella acerina from Acer (USA), Brunneiapiospora austropalmicola from Rhopalostylis (New Zealand), Calonectria pentaseptata from Eucalyptus and Macadamia (Vietnam), Ceramothyrium melastoma from Melastoma (Indonesia), Collembolispora aristata from stream foam (Czech Republic), Devriesia imbrexigena from glazed decorative tiles (Portugal), Microcyclospora rhoicola from Rhus (Canada), Seiridium phylicae from Phylica (Tristan de Cunha, Inaccessible Island), Passalora lobeliae-fistulosis from Lobelia (Brazil) and Zymoseptoria verkleyi from Poa (The Netherlands). Valsalnicola represents a new ascomycete genus from Alnus (Austria) and Parapenidiella a new hyphomycete genus from Eucalyptus (Australia). Morphological and culture characteristics along with ITS DNA barcodes are also provided.