A systematic overview of Descolea (Agaricales) in the Nothofagaceae forests of Patagonia

Discovering the role of Patagonian birds in the dispersal of truffles and other mycorrhizal fungi

Dispersal is a key process that impacts population dynamics and structures biotic communities. Dispersal limitation influences the assembly of plant and microbial communities, including mycorrhizal fungi and their plant hosts. Mycorrhizal fungi play key ecological roles in forests by feeding nutrients to plants in exchange for sugars, so the dispersal of mycorrhizal fungi spores actively shapes plant communities. Although many fungi rely on wind for spore dispersal, some fungi have lost the ability to shoot their spores into the air and instead produce enclosed belowground fruiting bodies (truffles) that rely on animals for dispersal. The role of mammals in fungal spore dispersal is well documented, but the relevance of birds as dispersal agents of fungi has been understudied, despite the prominence of birds as seed dispersal vectors. Here, we use metagenomics and epifluorescence microscopy to demonstrate that two common, widespread, and endemic Patagonian birds, chucao tapaculos (Scelorchilus rubecula) and black-throated huet-huets (Pteroptochos tarnii), regularly consume mycorrhizal fungi and disperse viable spores via mycophagy. Our metagenomic analysis indicates that these birds routinely consume diverse mycorrhizal fungi, including many truffles, that are symbiotically associated with Nothofagaceae trees that dominate Patagonian forests. Epifluorescence microscopy of fecal samples confirmed that the birds dispersed copious viable spores from truffles and other mycorrhizal fungi. We show that fungi are a common food for both bird species and that this animal-fungi symbiosis is widespread and ecologically important in Patagonia. Our findings indicate that birds may also act as cryptic but critical fungal dispersal agents in other ecosystems.

Thaxterogaster revisited: A phylogenetic and taxonomic overview of sequestrate Cortinarius from Patagonia

In the Patagonian region, Cortinarius is the most diverse and abundant genus of ectomycorrhizal fungi with at least 250 species. Sequestrate forms were until recently documented within the genus Thaxterogaster, a genus now known to be polyphyletic, and many were consequently transferred to Cortinarius. Original descriptions were mostly available in German and Spanish and interpretations of morphological structures outdated. Despite recent advances in Cortinarius systematics, the current classification, diversity, and ecology of sequestrate "cortinarioid" fungi in Patagonia remain unclear. The objective of this study was to provide an update on sequestrate Cortinarius of southern South America. We documented each species with morphological descriptions, photographs, basidiospore scanning electron microscopy (SEM) images, and molecular characterization using nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS) and nuc 28S rDNA (28S) sequence data. Original descriptions of taxa were also translated to English and revised based on fresh collections. We documented 24 species from Patagonia based on molecular data and conducted morphological and phylogenetic analysis for 18 previously described species based on type and reference specimens. In addition, we formally described two new species. Four additional taxa were provisionally determined as new but require further study. New ITS sequence data were produced from eight type specimens. We also provide a new name, Cortinarius gloiodes, nom. nov., for the taxon previously described as Thaxterogaster gliocyclus. In addition to the species treated in detail, we provided additional reference information and discussion on six described species that remained incompletely known or for which no recent collections were found. Of the 24 taxa documented from Patagonia, 15 species were assigned to 12 current sections in the genus Cortinarius. Analysis of spore ultrastructure showed that sequestrate forms of Patagonian Cortinarius lack a true perisporium.

Phylogenetic relationships in the genus Podoserpula and description of P. aliweni, a new species from Chile

Phylogenetic analyses based on a three-locus nuclear data set (ITS1-5.8S-ITS2, the 5' end of the 28S, and the largest subunit of RNA polymerase I) supported the pagoda fungus (Podoserpula, Amylocorticiales) as a monophyletic group most closely related to species of Anomoporia, which is nonmonophyletic, and Amyloathelia. Phylogenetic relationships inferred from internal transcribed spacer (ITS) sequences of specimens sampled in Australia, Chile, China, Madagascar, and New Zealand divided Podoserpula into two major lineages: Clade A containing Australian and New Zealand collections designated P. pusio and the Chinese species P. ailaoshanensis, which have basidiospores with no reaction to Melzer's reagent, and Clade B, which includes a species described from Chile, P. aliweni, and specimens originating from Australia, Chile, Madagascar, and New Zealand with dextrinoid basidiospores. Podoserpula aliweni forms a unique branch in the phylogenetic tree and differs from its most closely related taxon by 1.8-2.1% in the ITS region. The new species exhibits a tree-like habit with a white to concolorous stipe-like base with the hymenophore's main subcylindrical axis bearing up to 18 superimposed pilei, slightly enrolled white margins shading from yellowish white to orange-yellow toward the center, and ellipsoid to broadly ellipsoid basidiospores measuring 4.0-4.5 × 3.5 µm. Ecologically, P. aliweni occurs during the rainy season, often gregariously on dried branches or wet soil under Nothofagus dombeyi or N. obliqua and has a distribution range of more than 600 km in southern Chile. This study extends the known distributional range and increases our knowledge on the phylogenetic diversity and taxonomy in Podoserpula.

Loose Ends in the Cortinarius Phylogeny: Five New Myxotelamonoid Species Indicate a High Diversity of These Ectomycorrhizal Fungi with South American Nothofagaceae

This paper is a contribution to the current knowledge of taxonomy, ecology and distribution of South American Cortinarius (Pers.) Gray. Cortinarius is among the most widely distributed and species-rich basidiomycete genera occurring with South American Nothofagaceae and species are found in many distinct habitats, including shrublands and forests. Due to their ectomycorrhizal role, Cortinarius species are critical for nutrient cycling in forests, especially at higher latitudes. Some species have also been reported as edible fungi with high nutritional quality. Our aim is to unravel the taxonomy of selected Cortinarius belonging to phlegmacioid and myxotelamonioid species based on morphological and molecular data. After widely sampling Cortinarius specimens in Patagonian Nothofagaceae forests and comparing them to reference collections (including holotypes), we propose five new species of Cortinarius in this work. Phylogenetic analyses of concatenated rDNA ITS-LSU and RPB1 sequences failed to place these new species into known Cortinarius sections or lineages. These findings highlight our knowledge gaps regarding the fungal diversity of South American Nothofagaceae forests. Due to the high diversity of endemic Patagonian taxa, it is clear that the South American Cortinarius diversity needs to be discovered and described in order to understand the evolutionary history of Cortinarius on a global scale.

Four new species of sequestrate Inocybe from Chilean Nothofagaceae forests

Sequestrate fungi have enclosed hypogeous, subhypogeous, or epigeous basidiomes and have lost the ability to actively discharge their spores. They can be distinguished as gasteroid (basidiome fully enclosed with a loculated hymenophore) or secotioid (basidiome with some agaricoid or pileate-stipitate features, but the lamellae are misshapen and unexposed or mostly unexposed at maturity). There are only four reports of sequestrate taxa within the ectomycorrhizal family Inocybaceae, three from Australia and one from western North America. Recent field work in Nothofagaceae forests in the Chilean coastal range revealed novel sequestrate forms of Inocybe. We examined specimens using a combination of morphological and molecular data from nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS) and portions of nuc 28S rDNA (28S) and the gene encoding the second largest subunit of RNA polymerase II (rpb2). Here, we describe four new sequestrate Inocybe species, I. ranunculiformis, I. anfractuosa, I. illariae, and I. nahuelbutensis. Results of our phylogenetic analysis resolved the four new species as distinct species-level clades with strong support, suggesting that these fungi have convergently evolved sequestrate forms independently. The species described here were all placed along with members of the "smooth-spored temperate austral clade," which includes almost exclusively Australasian and South American species of Inocybe.

Hebeloma in the Malay Peninsula: Masquerading within Psathyrella

In 1994 Corner published five new species within the genus Psathyrella, all having been collected on the Malay Peninsula between 1929 and 1930. Three of these species belong to the genus Hebeloma and with their vinaceous colored lamellae and spore print, when fresh, they belong to H.sect.Porphyrospora. Of these three species, only one, P.flavidifolia, was validly published and thus we herewith recombine it as H.flavidifolium. The other two species, P.splendens and P.verrucispora, are synonyms of H.parvisporum and H.lactariolens, respectively. We also describe a new Malayan species, H.radicans, which also belongs to H.sect.Porphyrospora. These findings confirm the western Pacific Rim as a diversity hotspot for H.sect.Porphyrospora. The records described within this paper, represent the first recognition that the genus Hebeloma, and indeed that members of the ectomycorrhizal Hymenogastraceae, are present on the Malay Peninsula.

Entoloma sequestratum, a new species from northern Thailand, and a worldwide key to sequestrate taxa of Entoloma (Entolomataceae)

Based on our study of the morphology and genetics of sporocarps collected in the mountains of northern Thailand, we herein describe Entoloma sequestratum as a new sequestrate member of the Entolomotaceae. This serves as the first report of a sequestrate member of the genus from Thailand. In addition, we provide a worldwide key to all of the described sequestrate members of the genus.

Continental-scale metagenomics, BLAST searches, and herbarium specimens: The Australian Microbiome Initiative and the National Herbarium of Victoria

PREMISE

Motivated to make sensible interpretations of the massive volume of data from the Australian Microbiome Initiative (AusMic), we characterize the soil mycota of Australia. We establish operational taxonomic units (OTUs) from the data and compare these to GenBank and a data set from the National Herbarium of Victoria (MEL), Melbourne, Australia. We also provide visualizations of Agaricomycete diversity, drawn from our analyses of the AusMic sequences and taxonomy.

METHODS

The AusMic internal transcribed spacer (ITS) data were filtered to create OTUs, which were searched against the National Center for Biotechnology Information Nucleotide database and the MEL database. We further characterized a portion of our OTUs by graphing the counts of the families and orders of Agaricomycetes. We also graphed AusMic species determinations for Australian Agaricomycetes against latitude.

RESULTS

Our filtering process generated 192,325 OTUs; for Agaricomycetes, there were 27,730 OTUs. Based on the existing AusMic taxonomy at species level, we inferred the diversity of Australian Agaricomycetes against latitude to be lowest between -20 and -25 decimal degrees.

DISCUSSION

BLAST comparisons provided reciprocal insights between the three data sets, including the detection of unusual root-associated species in the AusMic data, insights into mushroom morphology from the MEL data, and points of comparison for the taxonomic determinations between AusMic, GenBank, and MEL. This study provides a tabulation of Australian fungi, different visual snapshots of a subset of those taxa, and a springboard for future studies.

Notes, outline and divergence times of Basidiomycota

The Basidiomycota constitutes a major phylum of the kingdom Fungi and is second in species numbers to the Ascomycota. The present work provides an overview of all validly published, currently used basidiomycete genera to date in a single document. An outline of all genera of Basidiomycota is provided, which includes 1928 currently used genera names, with 1263 synonyms, which are distributed in 241 families, 68 orders, 18 classes and four subphyla. We provide brief notes for each accepted genus including information on classification, number of accepted species, type species, life mode, habitat, distribution, and sequence information. Furthermore, three phylogenetic analyses with combined LSU, SSU, 5.8s, rpb1, rpb2, and ef1 datasets for the subphyla Agaricomycotina, Pucciniomycotina and Ustilaginomycotina are conducted, respectively. Divergence time estimates are provided to the family level with 632 species from 62 orders, 168 families and 605 genera. Our study indicates that the divergence times of the subphyla in Basidiomycota are 406–430 Mya, classes are 211–383 Mya, and orders are 99–323 Mya, which are largely consistent with previous studies. In this study, all phylogenetically supported families were dated, with the families of Agaricomycotina diverging from 27–178 Mya, Pucciniomycotina from 85–222 Mya, and Ustilaginomycotina from 79–177 Mya. Divergence times as additional criterion in ranking provide additional evidence to resolve taxonomic problems in the Basidiomycota taxonomic system, and also provide a better understanding of their phylogeny and evolution.

A worldwide nomenclature revision of sequestrate Russula species

Before the application of molecular techniques, evolutionary relationships between sequestrate genera and their epigeous counterparts in the Russulaceae were unclear. Based on overwhelming evidence now available, personal observations, and consideration of the International Code for Nomenclature of Algae, Fungi and Plants, we combine the overlapping sequestrate generic names Bucholtzia, Cystangium, Elasmomyces, Gymnomyces, Macowanites, and Martellia with the agaricoid genus Russula. This nomenclatural action follows precedents set by earlier mycologists and continues an effort to create clarity in our understanding of the evolutionary affiliations among sequestrate fungi - particularly the Russulaceae. We also provide the first comprehensive list of described sequestrate species of Russula.