Matthew E. Smith’s research while affiliated with University of Florida and other places

Ectomycorrhizal fungi in the genus Tuber form hypogeous fruiting bodies called truffles. Many Tuber species are highly prized due to their edible and aromatic ascomata. Historically, there has been attention on cultivating and selling European truffle species, but there is growing interest in cultivating, wild-harvesting, and selling species of truffles endemic to North America. North America has many endemic Tuber species that remain undescribed, including some that have favorable culinary qualities. Here, we describe two such Tuber species from eastern North America. Maximum likelihood and Bayesian phylogenetic analyses of ITS (internal transcribed spacer), tef1 (translation elongation factor 1-alpha), and rpb2 (second largest subunit of RNA polymerase II) sequences were used to place these species within a phylogenetic context. We coupled these data with morphological analyses and volatile analyses based on gas chromatography-mass spectrometry. Tuber cumberlandense, sp. nov. (previously referred to as Tuber sp. 66), is a member of the Rufum clade that has been opportunistically harvested for commercial sale from T. melanosporum orchards across eastern North America. Tuber canirevelatum, sp. nov. belongs in the Macrosporum clade and thus far is only known from eastern Tennessee, USA. Both new species were discovered with the assistance of trained truffle dogs. The volatile profiles of T. canirevelatum and T. cumberlandense were measured in order to characterize aromas based on the chemical compounds produced by these fungi. Ascomata from both species were enriched in acetone, dimethyl sulfide, 1-(methylthio)-1-propene, and 1-(methylthio)propane. In this work, we celebrate and encourage the use of trained truffle-hunting dogs for fungal biodiversity discovery and research.

Cistaceae are shrubs, subshrubs and herbs that often occur in stressful, fire-prone or disturbed environments and form ectomycorrhizal (ECM) associations with symbiotic fungi. Although some Cistaceae are long-lived shrubs that grow to significant size, others are herbaceous annuals or short-lived plants. Thus, Cistaceae are atypical ECM hosts that are fundamentally different in their biology from trees that are the more typically studied ECM hosts. The Mediterranean region is the center of diversity for Cistaceae and the ectomycorrhizal fungi associated with Cistaceae hosts have primarily been studied in Europe, North Africa, and the Middle East. Mediterranean Cistaceae often host diverse communities of ECM fungi, but they also act as hosts for some ECM fungi that putatively show host-specificity or strong host preference for Cistaceae (including species of Delastria, Hebeloma, Terfezia, and Tirmania). The ECM associations of Cistaceae in North America, however, remain highly understudied. Here we use fungal DNA metabarcoding to document the ectomycorrhizal fungal communities associated with Crocanthemum and Lechea (Cistaceae) in open, fire-prone sandhill habitats in north Florida. At each site we also sampled nearby Pinus to determine whether small, herbaceous Cistaceae have specialized ECM fungi or whether they share their ECM fungal community with nearby pines. The ECM communities of Florida Cistaceae are dominated by Cenococcum (Ascomycota) and Russula (Basidiomycota) species but were also significantly associated with Delastria, an understudied genus of mostly truffle-like Pezizales (Ascomycota). Although many Cistaceae ECM fungi were shared with neighboring pines, the ECM communities with Cistaceae were nonetheless significantly different than those of pines.

Subantarctic Nothofagus forests are the southernmost forests in the world, with negligible atmospheric nitrogen (N) deposition. Most paradigms about the role of ectomycorrhizal (ECM) fungi in N cycling and plant N uptake at high latitudes have been tested in boreal coniferous forests, while in the southern hemisphere, ECM hosts are primarily angiosperms. Using ITS1 meta‐barcoding, we characterized ECM and saprotrophic fungal communities in evergreen and deciduous Nothofagus forests forming monodominant and mixed stands in the archipelago of Tierra del Fuego (Chile and Argentina). We assessed the N economy of Nothofagus by correlating host species with fungal relative abundances, edaphic variables, net N mineralization, microbial biomass N and the activity of eight extracellular soil enzymes activities. The N economy of deciduous N. pumilio forests was strikingly similar to boreal coniferous forests, with the lowest inorganic N availability and net N mineralization, in correlation to higher relative abundances of ECM fungi with enzymatic capacity for organic N mobilization (genus Cortinarius). In contrast, the N economy of evergreen N. betuloides forests was predominantly inorganic and correlated with ECM lineages from the family Clavulinaceae, in acidic soils with poor drainage. Grassy understory vegetation in deciduous N. antarctica forests likely promoted saprotrophic fungi (i.e., genus Mortierella) in correlation with higher activities of carbon‐degrading enzymes. Differences between Nothofagus hosts did not persist in mixed forests, illustrating the range of soil fertility of these ECM angiosperms and the underlying effects of soil and climate on Nothofagus distribution and N cycling in southern Patagonia.

Presentation and illustration of a new species of the genus Paragalactinia, P. pseudomichelii, collected in Canada and the USA, based on morphological and molecular characters. An updated key to the genus Paragalactinia is also provided

Background Truffles are subterranean fungal fruiting bodies that are highly prized for their culinary value. Cultivation of truffles was pioneered in Europe and has been successfully adapted in temperate regions throughout the globe. Truffle orchards have been established in North America since the 1980s, and while some are productive, there are still many challenges that must be overcome to develop a viable North American truffle industry. These challenges include extended delays between establishment and production, comparatively low yields, high spatial heterogeneity in yield distribution, and orchard contamination with lower-value truffle fungi. Aim Here we review known requirements for truffle production including necessary environmental conditions, reproductive biology, and effective agronomic practices. Content We consider the potential limitations of importing exotic host-fungal associations into North America where there is already a rich community of competing ectomycorrhizal fungi, host pests and pathogens. We also describe the status of the North American truffle industry with respect to market potential, including production costs, pricing, and biological and socioeconomic risk factors. A critical aspect of modern trufficulture involves monitoring with genetic tools that supply information on identity, abundance and distribution of fungal symbionts, abundance of competitive and contaminating fungi, and insight into the interactions between fungal mating types that are fundamental to the formation of truffle primordia. Implications Cultivation of the ectomycorrhizal truffle symbiosis requires application of pragmatic agronomic practices, adopting rigorous quality control standards, and an understanding of fungal biology, microbiology, and molecular biology. Consequently, significant interdisciplinary collaboration is crucial to further develop the North American truffle industry.

Pezizales are a diverse and economically important order of fungi. They are common in the environment, having epigeous form, such as morels and hypogeous, forms called truffles. The mature ascospores of most epigeous Pezizales are forcibly discharged through an opening at the ascus apex created with the lifting of the operculum, a lid-like structure specific to Pezizales. The axenic cultures of Pezizales fungi isolated from single ascospores are important for understanding the life cycle, development, ecology, and evolution of these fungi. However, obtaining single-spore isolates can be challenging, particularly for collections obtained in locations where sterile work environments are not available. In this paper, we introduce an accessible method for harvesting ascospores from fresh ascomata in the field and laboratory for obtaining single-spore isolates. Ascospores are harvested on the inside cover of Petri plate lids in the field, air dried, and stored. At a later date, single-spore isolates are axenically cultured through serial dilution and plating on antibiotic media. With this approach, we were able to harvest ascospores and obtain single-spore isolates from 12 saprotrophic and 2 ectomycorrhizal species belonging to six Pezizales families: Discinaceae, Morchellaceae, Pezizaceae, Pyronemataceae, Sarcosomataceae, and Sarcoscyphaceae. This method worked well for saprotrophic taxa (12 out of 19 species, 63%) and was even effective for a few ectomycorrhizal taxa (2 out of 13 species, 15%). This process was used to study the initial stages of spore germination and colony development in species across several Pezizales families. We found germination often commenced with the swelling of the spore, followed by the emergence of 1–8 germ tubes. This method is sufficiently straightforward that, provided with sterile Petri dishes, citizen scientists from distant locations could use this approach to capture spores and subsequently mail them with voucher specimens to a research laboratory for further study. The generated single-spore Pezizales isolates obtained through this method were used to generate high-quality genomic data. Isolates generated in this fashion can be used in manipulative experiments to better understand the biology, evolution, and ecogenomics of Pezizales.

As the continuation of Fungal Diversity Notes series, the current paper is the 16th contribution to this series. A total of 103 taxa from seven classes in Ascomycota and Basidiomycota are included here. Of these 101 taxa, four new genera, 89 new species, one new combination, one new name and six new records are described in detail along with information of hosts and geographic distributions. The four genera newly introduced are Ascoglobospora, Atheliella, Rufoboletus and Tenuimyces. Newly described species are Akanthomyces xixiuensis, Agaricus agharkarii, A. albostipitatus, Amphisphaeria guttulata, Ascoglobospora marina, Astrothelium peudostraminicolor, Athelia naviculispora, Atheliella conifericola, Athelopsis subglaucina, Aureoboletus minimus, A. nanlingensis, Autophagomyces incertus, Beltrania liliiferae, Beltraniella jiangxiensis, Botryobasidium coniferarum, Calocybella sribuabanensis, Calonarius caesiofulvus, C. nobilis, C. pacificus, C. pulcher, C. subcorrosus, Cortinarius flaureifolius, C. floridaensis, C. subiodes, Crustomyces juniperi, C. scytinostromoides, Cystostereum subsirmaurense, Dimorphomyces seemanii, Fulvoderma microporum, Ginnsia laricicola, Gomphus zamorinorum, Halobyssothecium sichuanense, Hemileccinum duriusculum, Henningsomyces hengduanensis, Hygronarius californicus, Kneiffiella pseudoabdita, K. pseudoalutacea, Laboulbenia bifida, L. tschirnhausii, L. tuberculata, Lambertella dipterocarpacearum, Laxitextum subrubrum, Lyomyces austro-occidentalis, L. crystallina, L. guttulatus, L. niveus, L. tasmanicus, Marasmius centrocinnamomeus, M. ferrugineodiscus, Megasporoporia tamilnaduensis, Meruliopsis crystallina, Metuloidea imbricata, Moniliophthora atlantica, Mystinarius ochrobrunneus, Neomycoleptodiscus alishanense, Nigrograna kunmingensis, Paracremonium aquaticum, Parahelicomyces dictyosporus, Peniophorella sidera, P. subreticulata, Phlegmacium fennicum, P. pallidocaeruleum, Pholiota betulicola, P. subcaespitosa, Pleurotheciella hyalospora, Pleurothecium aseptatum, Resupinatus porrigens, Russula chlorina, R. chrysea, R. cruenta, R. haematina, R. luteocarpa, R. sanguinolenta, Synnemellisia punensis, Tenuimyces bambusicola, Thaxterogaster americanoporphyropus, T. obscurovibratilis, Thermoascus endophyticus, Trechispora alba, T. perminispora, T. subfarinacea, T. tuberculata, Tremella sairandhriana, Tropicoporus natarajaniae, T. subramaniae, Usnea kriegeriana, Wolfiporiella macrospora and Xylodon muchuanensis. Rufoboletus hainanensis is newly transferred from Butyriboletus, while a new name Russula albocarpa is proposed for Russula leucocarpa G.J. Li & Chun Y. Deng an illegitimate later homonym of Russula leucocarpa (T. Lebel) T. Lebel. The new geographic distribution regions are recorded for Agaricus bambusetorum, Bipolaris heliconiae, Crinipellis trichialis, Leucocoprinus cretaceus, Halobyssothecium cangshanense and Parasola setulosa. Corresponding to morphological characters, phylogenetic evidence is also utilized to place the above-mentioned taxa in appropriate taxonomic positions. The current morphological and phylogenetic data is helpful for further clarification of species diversity and exploration of evolutionary relationships in the related fungal groups.

Nidulariaceae, also known as bird’s nest fungi, is an understudied group of mushroom-forming fungi. The common name is derived from their nest-like morphology. Bird’s nest fungi are ubiquitous wood decomposers or saprobes on dung. Recent studies showed that species in the Nidulariaceae form a monophyletic group with five sub-clades. However, phylogenetic relationships among genera and placement of Nidulariaceae are still unclear. We present phylogenomic analyses of bird’s nest fungi and related Agaricales fungi to gain insight into the evolution of Nidulariaceae. A species tree with 17 newly generated genomes of bird’s nest fungi and representatives from all major clades of Agaricales was constructed using 1044 single-copy genes to explore the intergeneric relationships and pinpoint the placement of Nidulariaceae within Agaricales. We corroborated the hypothesis that bird’s nest fungi are sister to Squamanitaceae, which includes mushroom-shaped fungi with a stipe and pileus that are saprobes and mycoparasites. Lastly, stochastic character mapping of discrete traits on phylogenies (SIMMAP) suggests that the ancestor of bird’s nest fungi likely possessed an evanescent, globose peridium without strings attaching to the spore packets (funiculi). This analysis suggests that the funiculus was gained twice and that the persistent, cupulate peridium form was gained at least four times and lost once. However, alternative coding schemes and datasets with a wider array of Agaricales produced conflicting results during ancestral state reconstruction, indicating that there is some uncertainty in the number of peridium transitions and that taxon sampling may significantly alter ancestral state reconstructions. Overall, our results suggest that several key morphological characters of Nidulariaceae have been subject to homoplasy.