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Mushroom-forming fungi (Agaricomycetes) have the greatest morphological diversity and complexity of any group of fungi. They have radiated into most niches and fulfil diverse roles in the ecosystem, including wood decomposers, pathogens or mycorrhizal mutualists. Despite the importance of mushroom-forming fungi, large-scale patterns of their evolutionary history are poorly known, in part due to the lack of a comprehensive and dated molecular phylogeny. Here, using multigene and genome-based data, we assemble a 5,284-species phylogenetic tree and infer ages and broad patterns of speciation/extinction and morphological innovation in mushroom-forming fungi. Agaricomycetes started a rapid class-wide radiation in the Jurassic, coinciding with the spread of (sub)tropical coniferous forests and a warming climate. A possible mass extinction, several clade-specific adaptive radiations and morphological diversification of fruiting bodies followed during the Cretaceous and the Paleogene, convergently giving rise to the classic toadstool morphology, with a cap, stalk and gills (pileate-stipitate morphology). This morphology is associated with increased rates of lineage diversification, suggesting it represents a key innovation in the evolution of mushroom-forming fungi. The increase in mushroom diversity started during the Mesozoic-Cenozoic radiation event, an era of humid climate when terrestrial communities dominated by gymnosperms and reptiles were also expanding.

Species of the ectomycorrhizal (ECM) family Cortinariaceae (Agaricales, Agaricomycetes, Basidiomycota) have long been considered impoverished or absent from lowland tropical rainforests. Several decades of collecting in forests dominated by ECM trees in South America's Guiana Shield is countering this view, with discovery of numerous Cortinariaceae species. To date, ~12 morphospecies of this family have been found in the central Pakaraima Mountains of Guyana. Here, we describe three of these as new species of Cortinarius and two as new species of Phlegmacium from forests dominated by the ECM tree genera Dicymbe (Fabaceae subfam. Detarioideae), Aldina (Fabaceae subfam. Papilionoideae), and Pakaraimaea (Cistaceae). Macromorphological, micromorphological, habitat, and DNA sequence data are provided for each new species. [ABSTRACT FROM AUTHOR]

Cortinarius is the largest genus of Agaricales (mushrooms) in the world with a cosmopolitan distribution. All species are ectomycorrhizal. Cortinariaceae is a very diverse fungal family, recently split into ten genera, one of which is Cortinarius. The former genus Cortinarius s. lato, in its turn, was traditionally divided into 4–7 subgenera, of which one of the later additions is the subgenus Leprocybe. Here we review the diversity of Leprocybe in the Southern Hemisphere. Using a 4-locus molecular phylogeny, it is shown that all but one of M. Moser’s original sections are represented in the South Pacific region, many of them in New Zealand. Several species sharing a morphology that may be designated ‘leprocyboid’ are found in the country. These are discussed, their taxonomy is analysed, and a key is provided. Three new species (Aureonarius ruficollybianus, Cortinarius stenophryx, and Cystinarius pseudoeutactus) are proposed. The leprocyboid Cortinarius sect. Incensi, present in New Zealand, appears not to nest in any of the studied genera, but an analysis with more genes and a wider taxon sampling is required to clarify its position within the phylogeny of the family. [ABSTRACT FROM AUTHOR]

Stipitate Thelephorales are basidiomycetous, mostly hydnoid, ectomycorrhizal fungi. Some species have declined considerably, and some are threat-listed as vulnerable or endangered. These ecological concerns require a well-resolved taxonomy to understand diversity in this group of fungi and facilitate conservation. However, phylogenetic studies have mostly neglected Southern Hemisphere representatives. This study examines the fleshy species of stipitate Thelephorales from native forests in Australia and New Zealand, using morphological analyses and phylogenetic analyses of nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode) and D1–D2 domains at the 5′ end of nuc 28S rDNA (28S) sequences amplified from DNA isolated from fungarium collections and environmental DNA (eDNA) sequences from the Australian Microbiome initiative. Five new species, Sarcodon austrofibulatus, Hydnellum gatesiae, H. nothofagacearum, H. pseudoioeides, and H. variisporum, are described, Sarcodon carbonarius is transferred to Neosarcodon, and a key is provided for the six named species in the region. Boletopsis and Neosarcodon are reported from Australia for the first time based on detections from eDNA in soil samples taken from native forests. The Australasian species of Hydnellum occupy a highly derived position with the phylogeny of the genus, the members of which are otherwise all from the Northern Hemisphere, suggestive of a long-distance dispersal origin for the Australasian species. [ABSTRACT FROM AUTHOR]

Alien plant pathogens are a threat to native plants and are increasingly integrating into native plant–pathogen networks, but how these novel plant–pathogen networks are structured remains unclear. Theory predicts that novel antagonists are likely to be generalists, resulting in interaction networks with greater nestedness as well as lower modularity and specialization than native networks.We tested these predictions by quantifying associations between native plants and their native and alien pathogens using a comprehensive database of plant–fungal associations in New Zealand. We compared the host ranges of alien and native pathogens and the structure of native and alien pathogen subnetworks.As predicted, alien pathogens associated with a greater number and diversity of native plant host species than native pathogens. The alien pathogen subnetwork was more nested and connected, but less modular and less specialized than the native pathogen subnetwork, consistent with expectations for novel interactions. Alien pathogens altered the overall native plant–pathogen network structure, making the full network more connected and less specialized than the native network. Modules in the native and alien subnetworks were clustered by host phylogeny but did not show a clear signal associated with host habitat or region.Synthesis. Our study provides some of the first empirical insights into the structure of novel plant–pathogen networks and the changes that occur when alien pathogens invade a native network. Because alien pathogens interacted with more hosts than native pathogens, alien pathogens have an increased risk of adverse indirect effects, including pathogen spillover, host jumps and network destabilization. [ABSTRACT FROM AUTHOR]