Import volumes and biosecurity interventions shape the arrival rate of fungal pathogens.

Global trade and the movement of people accelerate biological invasions by spreading species worldwide. Biosecurity measures seek to allow trade and passenger movements while preventing incursions that could lead to the establishment of unwanted pests, pathogens, and weeds. However, few data exist to evaluate whether changes in trade volumes, passenger arrivals, and biosecurity measures have altered rates of establishment of nonnative species over time. This is particularly true for pathogens, which pose significant risks to animal and plant health and are consequently a major focus of biosecurity efforts but are difficult to detect. Here, we use a database of all known plant pathogen associations recorded in New Zealand to estimate the rate at which new fungal pathogens arrived and established on 131 economically important plant species over the last 133 years. We show that the annual arrival rate of new fungal pathogens increased from 1880 to about 1980 in parallel with increasing import trade volume but subsequently stabilised despite continued rapid growth in import trade and recent rapid increases in international passenger arrivals. Nevertheless, while pathogen arrival rates for crop and pasture species have declined in recent decades, arrival rates have increased for forestry and fruit tree species. These contrasting trends between production sectors reflect differences in biosecurity effort and suggest that targeted biosecurity can slow pathogen arrival and establishment despite increasing trade and international movement of people.

Taxonomic similarity, more than contact opportunity, explains novel plant-pathogen associations between native and alien taxa.

Novel associations between plants and pathogens can have serious impacts on managed and natural ecosystems world-wide. The introduction of alien plants increases the potential for biogeographically novel plant-pathogen associations to arise when pathogens are transmitted from native to alien plant species and vice versa. We quantified biogeographically novel associations recorded in New Zealand over the last 150 yr between plant pathogens (fungi, oomycetes and plasmodiophorids) and vascular plants. We examined the extent to which taxonomic similarity, pathogen traits, contact opportunity and sampling effort could explain the number of novel associates for host and pathogen species. Novel associations were common; approximately one-third of surveyed plants and pathogens were recorded with at least one biogeographically novel associate. Native plants had more alien pathogens than vice versa. Taxonomic similarity between the native and alien flora and the total number of recorded associations (a measure of sampling effort) best explained the number of novel associates among species. The frequency of novel associations and the importance of sampling effort as an explanatory variable emphasize the need for effective monitoring and risk assessment tools to mitigate the potential environmental and economic impact of novel pathogen associations.

Molecular phylogeny and global diversity of the remarkable genus Bondarzewia (Basidiomycota, Russulales).

Bondarzewia is a remarkable polypore genus due to its relatively large poroid basidiocarps and belongs to order Russulales according to recent phylogenetic analyses. Two species, B. berkeleyi and B. mesenterica, are commonly reported in North America and Europe but the genus is poorly known elsewhere. We explored the phylogeny and species diversity of Bondarzewia based on a larger number of samples covering a wider geographic range, including eastern Asia, Europe, North America, Oceania and South America. Sequences were generated from the nuc rDNA region encompassing the internal transcribed spacers 1 and 2, along with the 5.8S rDNA (ITS) and nuc 28S rDNA D1-D2 domains (28S), and the final dataset included 28 samples of which 21 ITS and 28S sequences were newly generated. As a result of phylogenetic analyses and comparison of morphological features we propose a new classification of the genus recognizing 10 species. Most of the novel taxonomic concepts are geographically restricted in contrast to the past broad species concepts, especially of B. berkeleyi In addition, a degree of host specificity is observed with B. mesenterica, B. occidentalis, B. podocarpi, B. propria and B. submesenterica apparently restricted to gymnosperms and all others on angiosperm hosts where known. Three new species, B. kirkii, B. occidentalis and B. submesenterica, are described and illustrated. Three new combinations (B. dickinsii, B. propria, B. retipora) are revived from synonymy under B. berkeleyi A key to known species of Bondarzewia is provided.

Psathyloma, a new genus in Hymenogastraceae described from New Zealand.

A new genus Psathyloma is described based on collections of agarics from New Zealand. We describe two new species in the genus, Ps. leucocarpum and Ps. catervatim, both of which have been known and tentatively named for a long time awaiting a formal description. Morphological traits and phylogenetic analyses reveal that Psathyloma forms a strongly supported sister clade to Hebeloma, Naucoria and Hymenogaster Morphologically Psathyloma resembles Hebeloma from which it differs mainly by producing smooth basidiospores with a germ pore. The geographical range of the genus has been demonstrated to include several regions in the southern hemisphere. A survey of published environmental sequences reveals that Psathyloma spp. were isolated from ectomycorrhizal root tips from Tasmania and Argentina, indicating an ectomycorrhizal association with southern beech.

New Cortinariaceae species associated with Dicymbe, Aldina, and Pakaraimaea in Guyana.

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.

A phylogenetic overview of Squamanita, with descriptions of nine new species and four new combinations.

Nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode) sequence data from eight type specimens of previously described Squamanita species were obtained. Phylogenetic analysis of ITS and partial nuc 28S rDNA data revealed Squamanita as paraphyletic splitting into two monophyletic groups, which we recognize as the genera Squamanita and Dissoderma. We accept 14 Squamanita and nine Dissoderma species, provide the first sequences of 13 of these, and describe six new species of Squamanita and three new species of Dissoderma. We transfer three species of Squamanita into Dissoderma, one into Cystoderma, and treat S. basii and S. umbilicata as synonyms of D. paradoxum. Squamanita can be distinguished from Dissoderma by the generally larger fleshier basidiomata with a tricholomatoid or amanitoid stature and yellowish to tawny brown pileus and often similarly colored stipe. Most species have cheilo- and pleurocystidia. Species of Dissoderma are small, collybioid or mycenoid, lack cystidia, and the pileus and often upper stipe are purplish gray. Both genera parasitize basidiomata of other agarics.

Phylogeny and Diversity of the Genus Pseudohydnum (Auriculariales, Basidiomycota).

The toothed jelly fungus Pseudohydnum gelatinosum was originally described from Europe. The name has a broad sense and the species has been widely reported almost all over the world. We have studied samples of so-called P. gelatinosum from Asia and Oceania. Based on morphology, hosts, geography, and phylogenetic analysis using the internal transcribed spacer regions (ITSs) and the large subunit of nuclear ribosomal RNA gene (nLSU), four new species, P. himalayanum, P. orbiculare, P. sinogelatinosum, and P. tasmanicum, from China, New Zealand, and Australia are described and illustrated, and a new combination, Pseudohydnum totarae, is proposed. The five new taxa can be differentiated by the shape of their basidiomata, pileal surface color when fresh, spine size, basidiospore dimensions, shape of hyphidia, hosts, and biogeography. Phylogenetically, most of these taxa are distantly related, and different base pairs among these taxa mostly account for >2% nucleotides in the ITS regions.

Co-invasion by Pinus and its mycorrhizal fungi.

SUMMARY: *The absence of co-evolved mutualists of plants invading a novel habitat is the logical corollary of the more widely recognized 'enemy escape'. To avoid or overcome the loss of mutualists, plants may co-invade with nonnative mutualists, form novel associations with native mutualists or form associations with native cosmopolitan mutualists, which are native but not novel to the invading plant. *We tested these hypotheses by contrasting the ectomycorrhizal fungal communities associated with invasive Pinus contorta in New Zealand with co-occurring endemic Nothofagus solandri var. cliffortioides. *Fungal communities on Pinus were species poor (14 ectomycorrhizal species) and dominated by nonnative (93%) and cosmopolitan fungi (7%). Nothofagus had a species-rich (98 species) fungal community dominated by native Cortinarius and two cosmopolitan fungi. *These results support co-invasion by mutualists rather than novel associations as an important mechanism by which plants avoid or overcome the loss of mutualists, consistent with invasional meltdown.

Purple haze: Cryptic purple sequestrate Cortinarius in New Zealand.

CORTINARIUS: is a species-rich ectomycorrhizal genus containing taxa that exhibit agaricoid or sequestrate basidiome morphologies. In New Zealand, one of the most recognizable and common Cortinarius species is the purple sequestrate fungus, C. porphyroideus. We used genome skimming of the almost 100-y-old type specimen from C. porphyroideus to obtain the nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode) and partial nuc rDNA 28S (28S) sequences. The phylogenetic position of C. porphyroideus was established, and we found that it represents a rarely collected species. Purple sequestrate Cortinarius comprise multiple cryptic species in several lineages. We describe four new species of Cortinarius with strong morphological similarity to C. porphyroideus: Cortinarius diaphorus, C. minorisporus, C. purpureocapitatus, and C. violaceocystidiatus. Based on molecular evidence, Thaxterogaster viola is recognized as Cortinarius violaceovolvatus var. viola. These species are associated with Nothofagus (southern beech) and have very similar morphology to C. porphyroideus but are all phylogenetically distinct based on molecular data.

Megaphylogeny resolves global patterns of mushroom evolution.

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.

Overview of Phacidiales, including Aotearoamyces gen. nov. on Nothofagus.

The new genus Aotearoamyces is proposed to accommodate a single species that was repeatedly collected on fallen wood in Nothofagaceae forests of New Zealand and was previously misidentified as a Claussenomyces species. This monotypic genus belongs to Tympanidaceae, a recently erected family in Phacidiales. Aotearoamyces is differentiated from other Tympanidaceae by phragmospores that do not form conidia either in or outside the asci, an exciple of textura intricata with hyphae widely spaced and strongly gelatinized (plectenchyma), and apically flexuous, partly helicoid paraphyses. The asexual morph was studied in pure culture. Phylogenetic analyses of combined SSU, ITS and LSU sequences strongly support a sister relationship between the sexually typified Aotearoamyces and the asexually typified "Collophorina" paarla characterized morphologically by forming endoconidia, a feature not found in the genetically distinct type species of Collophorina. Based on our molecular results, we place the genus Epithamnolia in the Mniaecia lineage within Phacidiales.

Loss of functional diversity and network modularity in introduced plant-fungal symbioses.

The introduction of alien plants into a new range can result in the loss of co-evolved symbiotic organisms, such as mycorrhizal fungi, that are essential for normal plant physiological functions. Prior studies of mycorrhizal associations in alien plants have tended to focus on individual plant species on a case-by-case basis. This approach limits broad scale understanding of functional shifts and changes in interaction network structure that may occur following introduction. Here we use two extensive datasets of plant-fungal interactions derived from fungal sporocarp observations and recorded plant hosts in two island archipelago nations: New Zealand (NZ) and the United Kingdom (UK). We found that the NZ dataset shows a lower functional diversity of fungal hyphal foraging strategies in mycorrhiza of alien as compared with native trees. Across species this resulted in fungal foraging strategies associated with alien trees being much more variable in functional composition compared with native trees, which had a strikingly similar functional composition. The UK data showed no functional difference in fungal associates of alien and native plant genera. Notwithstanding this, both the NZ and UK data showed a substantial difference in interaction network structure of alien trees compared with native trees. In both cases, fungal associates of native trees showed strong modularity, while fungal associates of alien trees generally integrated into a single large module. The results suggest a lower functional diversity (in one dataset) and a simplification of network structure (in both) as a result of introduction, potentially driven by either limited symbiont co-introductions or disruption of habitat as a driver of specificity due to nursery conditions, planting, or plant edaphic-niche expansion. Recognizing these shifts in function and network structure has important implications for plant invasions and facilitation of secondary invasions via shared mutualist populations.

Three cocrystals and a cocrystal salt of pyrimidin-2-amine and glutaric acid.

Four new cocrystals of pyrimidin-2-amine and propane-1,3-dicarboxylic (glutaric) acid were crystallized from three different solvents (acetonitrile, methanol and a 50:50 wt% mixture of methanol and chloroform) and their crystal structures determined. Two of the cocrystals, namely pyrimidin-2-amine-glutaric acid (1/1), C4H5N3·C6H8O4, (I) and (II), are polymorphs. The glutaric acid molecule in (I) has a linear conformation, whereas it is twisted in (II). The pyrimidin-2-amine-glutaric acid (2/1) cocrystal, 2C4H5N3·C6H8O4, (III), contains glutaric acid in its linear form. Cocrystal-salt bis(2-aminopyrimidinium) glutarate-glutaric acid (1/2), 2C4H6N3(+)·C6H6O4(2-)·2C6H8O4, (IV), was crystallized from the same solvent as cocrystal (II), supporting the idea of a cocrystal-salt continuum when both the neutral and ionic forms are present in appreciable concentrations in solution. The diversity of the packing motifs in (I)-(IV) is mainly caused by the conformational flexibility of glutaric acid, while the hydrogen-bond patterns show certain similarities in all four structures.