Spore Size Research Articles

Suberose- a Doença Profissional mais Portuguesa

Introduction/ background/ objectives Portugal is the world’s largest producer of cork. It is derived from the cork oak (quercus suber) and consists of dead cells with cellulose. The tasks with the highest load are usually assigned to the male and the most repetitive to the female; this implies a different occupational exposure, meaning that exposures of higher risk generally occur almost exclusively in male positions. The first reference to Suberose (cork = suber) was in 1947. However, most studies in the sector were carried out in companies with good working conditions, so the conclusions may not be easily extrapolated to most cork workers. The aim of this bibliographic review is to summarize the most relevant information about the topic. Methodology This is a Bibliographic Review, initiated through a survey conducted in October 2020 in the databases “CINALH plus with full text, Medline with full text, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Cochrane Methodology Register, Nursing and Allied Health Collection: comprehensive, MedicLatina and RCAAP ”. Content The first articles related to the Cork sector highlight the role that some microorganisms have, like Penicillium glabrum (formerly known as frequentans); more recent documents add Chrysonilia Sitophila and Mucor. In places with less humidity the fungal concentration decreases. Workers with Suberosis had skin reactions to the fungus in question and the inhalation of the respective aerosols caused the characteristic symptoms. Some authors also believe that some mites may have some relevance in cork asthma (such as P notatum, Cladosporium, A fumigatus, Alternaria alternata, Acarus siro and Tyrophagus putrescentiae). The suberin found abundantly in cork, may also be associated with some symptoms. Workers are also exposed to cork dust; yet it is less prevalent in the workplace than fungi. Suberose is a pathology of the pulmonary interstitium caused by repeated exposure to dust and mold from cork; in fact, it is the most prevalent disease of the pulmonary interstitium in the north of the country. However, Asthma may also be associated with a lower prevalence. Depending on the size of the fungal spores, Asthma or Hypersensitivity Pneumonitis will be more likely, that is, if smaller (1 to 2 micromers), an alveolar response (alveolitis) will appear more frequently; if larger, a bronchial response, like asthma, can occur. Conclusions The cork industry is reasonably developed in some areas of the country, but knowledge about Suberosis is not always abundant. It would be relevant that all professionals in the Occupational Health Teams with clients in this area were comfortable in the way how to approach the sector; in addition, it is very relevant to develop recent research, disseminating it internationally, not least because Portugal is the country that most developed the sector, worldwide.

The Biogeography of Polyploid Ferns Across Space and Time

A review of work on the origin and phylogenetic relationships of six systems of allopolyploid homosporous ferns and their progenitors serves as the basis for assessing the history and status of ideas relating to the biogeography of polyploid ferns. The likely dates of origin for the polyploids from recent analyses provide a historical context not previously available, making possible rigorous tests of hypotheses about the history of polyploids, especially the origin, distribution, and duration of polyploid ferns as lineages. Insularity figures prominently in developing an understanding of polyploid fern biogeography. The origin and persistence of polyploid ferns is enhanced by the empty niche space and high disturbance on Darwinian islands. In addition, the greater precinctiveness of polyploid ferns related to larger spore size is likely a selective advantage on islands, consistent with the number of high polyploids encountered among ferns on oceanic islands. Though recently originated polyploid ferns usually have identifiable progenitors with which they are partially sympatric, the rate of expansion of these ferns beyond the range of their progenitors varies. In two cases from Austral regions, long-term persistence and divergent speciation have been demonstrated in widespread polyploids and polyploid lineages with unknown diploid progenitors, though the general consensus is that polyploids do not persist in the long term.

Morphological Study of Bacillus thuringiensis Crystals and Spores

In this paper, we report a morphological study of the crystals and spores of different shapes synthesized by seven different strains of Bacillus thuringiensis. Crystals and spores were separated after 48 h of culture on T3 agar medium and imaged under a scanning electron microscope (SEM). Sizes of the crystals and spores were determined using Image J software. The results showed that crystal and spore sizes were normally distributed. In addition, the volumes and aspect ratios of the crystals and spores were calculated. The statistical analysis of the data showed the variability of the size distribution and morphological data of the crystals produced by the analyzed strains. Furthermore, variations in spore size and shape within the same serovar were observed, indicating that, perhaps, there are still some unexplored differences between strains of this serovar, making them less identical than what was believed so far.

Identification of Fungal Isolates from Soils of Rice and Napier Grass

Microbial diversity of cultivated soil is the key resource for maintaining the functional capacity of agricultural and natural ecosystem. The research aimed to study the prevalence of soil fungi from the soils of rice and napier grass fields. Soil samples were collected from the fields of rice in flooded condition and napier grass in the upland condition at the University farm. Soil fungi were cultured on RB media through the serial dilution method. A total of 13 isolates were cultured, in which 11 from the soil collected from rice cultivated field and 2 from napier grass field. Seven out of 11 isolates collected from rice and 2 from napier grass were selected and identified through the morphological characters such as colony color, mycelium diameter, color and segmentaiton, spore size and color. Mycelium growths were examined on the PDA and RB media. Fungal isolates collected in this study were morphologically identified/ characterized as Aspergillus niger, A. flavus, A. terreus, A. carbonarius, A. nidulans, Alternaria sp., Penicillium and Talaromyces. Fungal species differed among the soils were discussed.

Isolation of the Parasite Enterocytospora artemiae From Chinese Grass Shrimp (Palaemonetes sinensis)-First Report in Asia.

Chinese grass shrimp (Palaemonetes sinensis) is an economically important crustacean in Chinese aquaculture. Recently, we found that shrimp in Panjin city were infected with microsporidia, a group of fungi. The hepatopancreas of several infected shrimp showed white turbidity and pathological changes that negatively affected the health and appearance of the shrimp. Histopathology and transmission electron microscopy were used to examine the development of the parasite within its parasitophorous vacuole. Our results indicated that microsporidia developed asynchronously within the same parasitophorous vacuole. The spores were predominantly small, and rod or oval-shaped. The sizes of fresh spores were approximately 3.1 × 2.4 μm and fixed spores were 1.9 × 1.1 μm. The polar filament was isofilar with 5–6 coils and the thickness was 103.2 nm. Merogonial divisions occurred by binary fission and sporogonial division occurred by plasmotomy. The small subunit ribosomal DNA sequence (1295 bp) from the parasite was highly similar to the previously reported parasite Enterocytospora artemiae (99% nucleotide identity, JX915760). Using maximum likelihood to analyze the phylogenetic relationships, we found that this microsporidian should be grouped within Clade IV, an Enterocytospora-like clade, of the Microsporidia phylum. Based on this parasite’s life cycle characteristics, morphology, and small subunit ribosomal DNA sequence, the parasite described here is likely E. artemiae, which has previously only been described in Europe and North America. Thus, this is the first report of E. artemiae both in Asia and economically important shrimp.

Arcyria versicolor of western mountains, U.S.A. (Myxomycetes: Trichiales: Trichiaceae): a morphological and taxonomic study with observations of nivicolous species

Arcyria versicolor (Trichiales: Trichiaceae) is a distinct myxomycete species described by William Phillips in 1877. The genus Arcyria dates back to Linnaeus in 1753 through the species A. denudata. Arcyria sporangia are brightly colored red, yellow, grey or white, mostly stalked, often in large groups easily seen with the naked eye. Approximately 54 species are known, many are common, and distributed worldwide. Collectors often encounter these colorful species on decaying logs as clusters of many sporangia often covering extensive areas. Arcyria versicolor, collected in the Valles Caldera National Preserve located in the Jemez Mountains of north central New Mexico, is a new record for the state. The nomenclatural history of this species is reviewed and the justification for selection of the species name versicolor is discussed. Arcyria versicolor is accepted as the valid species name and A. vitellina a synonym after examination of type specimens. Environmental parameters for coloration are discussed in general for fruiting bodies of Arcyria and more specifically for nivicolous snowbank species. Transitional stages of plasmodial color to mature fruiting body formation are described for Arcyria versicolor. More than 140 specimens of Arcyria versicolor fruiting bodies were examined with light microscopy and in part illustrated with multifocal computer stacked imaging. Higher magnifications were highlighted using scanning electron microscopy. A more complete and accurate species description is provided for Arcyria versicolor. Differences of fruiting body morphology including habit, color, dehiscence, peridial inner and outer surface features, capillitial ornamentation and size, spore color, size, and ornamentation, and stalk spore-like bodies are described and illustrated. Observation of type specimens from the type locality is illustrated, discussed, and nomenclatural evaluation given for the name selected. Mountain myxomycetes are reviewed based on the observations of T.H. Macbride and his early 1914 paper published in Mycologia. Collection data is presented that compares the dark-spored and light spored nivicolous myxomycetes in the French Alps. The history of renown collectors of nivicolous myxomycetes in western mountains of U.S.A. documents the discovery and study of this special ecological group of myxomycetes. This current paper is the first in a series from an ongoing research project entitled Myxomycetes of New Mexico.

Cytotypes of bracken (Pteridium aquilinum) in Europe: widespread diploids and scattered triploids of likely multiple origin

Polyploidization is an important speciation and evolution mechanism in ferns. Initially, new cytotypes face challenges in maintaining themselves within the majority cytotype populations. Unlike in most even-ploidy cytotypes, fern triploids are often apomictic or infertile, due to genetic imbalance. An interesting opportunity to study these phenomena has emerged with the discovery of triploid bracken (Pteridium aquilinum), a triploid fern that is fertile but not apomictic. Originally found in one Welsh population, the distribution of this cytotype in Europe is unknown as is its origin and how it maintains itself among the presumed diploid majority. We sampled 135 populations of P. aquilinum, focusing on Central Europe. Ploidy level of all samples was analyzed by flow cytometry. We compared the two cytotypes via micromorphological characters (spore and stomata size), fertility characteristics (spore abortion and proportion of populations with sporangia-bearing fronds). Additionally, genetic difference between ploidy levels was tested as well. The diploid cytotype of P. aquilinum is dominant in continental Europe with 121 entirely diploid populations found, but we also found 9 mixed and 5 entirely triploid populations. Fertile diploid and triploid plants were found only in 17.7% and 21.4% of populations, respectively. The cytotypes are distinguishable using both tested micromorphological characters, but stomata are more reliable due to overall reduced fertility. Unlike the Welsh specimen, our tested triploid has most spores aborted, ca 97.4%, compared to mean 6.0% of spores aborted in diploids. The triploid cytotype is rare and likely originated multiple times from the diploids and relies on clonal and possibly limited sexual reproduction to maintain itself. However, diploids and triploids are often genetically different within a population, indicating that the triploid may migrate between populations. Due to its vegetative growth and presumed continuous formation, the triploid cytotype is likely to remain established in Central Europe, although in small numbers.

Identification and characterization of three microsporidian genera concurrently infecting a silkworm, Bombyx mori, in Brazil

Microsporidia are important entomopathogens known for infecting insects such as the silkworm (Bombyx mori) thus impairing global silk production. This study aimed to identify and characterize the microsporidia isolated from a diseased larva of silkworm, collected from a sericulture farm in southern Brazil. Identification was performed by phylogenetic analysis of the nucleotide sequences of the SSU rRNA genes. Characterization was performed by analyzing spore sizes, tissue tropism, internal and external symptoms, and pathogenicity against B. mori. Microsporidia belonging to three different genera were identified, namely, Endoreticulatus, Nosema and Tubulinosema. After inoculation of the mixed spores of the microsporidian isolates into B. mori larvae, a high prevalence of Tubulinosema spp. was observed. This isolate showed high prevalence on the silk glands and a late mortality, initially of around 10% until the 20th day post-inoculation but reaching 91.5% upon pupation. Therefore, we demonstrated that Tubulinosema spp. causes chronic infection with slow pathogenicity. We identified for the first time three different microsporidians concurrently infecting B. mori in Brazil. Tubulinosema is of particular interest because of its potential threat to silk production; it affects the formation of silk glands in B. mori while not presenting distinguishable external symptoms or causing the immediate death of these insects. Further studies focusing on this species, mainly regarding its life cycle within the host and the sublethal effects of surviving individuals, demonstrate the importance of describing it as a new species and improving the characterization of the disease in order to prevent its spread.

Dimorphic Sexual Expression and Anisospory in Homalothecium sericeum Schimp. s.l. (Brachytheciaceae) in Portugal

Among terrestrial plant species, male dwarfism (nannandry) is a unique feature of bryophytes, common in numerous dioicous pleurocarpous mosses. In this study, our objective was to describe and to elucidate the incidence of dwarf males in Portuguese populations of Homalothecium sericeum (Hedw.) Schimp and H. meridionale (M. Fleisch. & Warnst.) Hedenas. We also evaluated the occurrence of sporophytes and of dwarf males, in 150 selected samples from the LISU herbarium collection. The results showed that most samples are heteromorphic, with sporophytes, and include dwarf males, independent marginal male branches and/or caducous brood branches as vegetative propagules. The samples containing only independent male plants are infrequent. Anisospory was observed in both species, with a perceptible bimodal distribution of spore size in both species. Moreover, in Portugal no differences were found between the two species of this complex concerning the presence and relative position of male plants, the occurrence of anisospory, or the strategies exhibited by male plants, such as nannandry and caducous branches.

Morphological Characterization and Determination of Aflatoxigenic and Non-Aflatoxigenic Aspergillus flavus Isolated from Sweet Corn Kernels and Soil in Malaysia

This study aimed to morphologically characterize and determine the aflatoxigenic and non-aflatoxigenic Aspergillus flavus isolates. Forty isolates of A. flavus were obtained from sweet corn kernels and soil samples collected from Kampong Raja, Rose Valley, Kea, and Klebang farms in Malaysia. They were cultured on potato dextrose agar (PDA), dichloran rose-bengal chloramphenicol (DRBC), Aspergillusflavus and Aspergillus parasiticus agar (AFPA), and coconut cream agar (CCA). Macromorphological characteristics were determined by observing the colony color and texture, while the micromorphological characteristics were determined by examining the spore color, size, structure, conidiophore structure, and vesicle shape. The production of aflatoxin was determined by direct visualization of the UV fluorescence of A. flavus colonies on CCA. Aflatoxin was qualitatively detected in 18 (45%) isolates of A. flavus using UV fluorescence screening while the remaining 22 (55%) isolates did not exhibit any aflatoxin production. The highest incidence of A. flavus (30%) and aflatoxin production (15%) was recorded in samples from Kampong Raja. On the other hand, isolates from Rose Valley (17%) and Kea (12%) were non-aflatoxigenic. Klebang recorded a 25% incidence of A. flavus in which 15% were aflatoxigenic while 10% were non-aflatoxigenic. The occurrence of aflatoxin-producing A. flavus emphasizes the need for the measure to eradicate their presence in food crops. A biological control treatment utilizing the non-aflatoxigenic strains to compete with the aflatoxigenic ones is underway. Validation of aflatoxin production through high performance liquid chromatography is also ongoing.

Parasexual recombination enablesAspergillus fumigatusto persist in cystic fibrosis

Aspergillus fumigatus is a saprobic fungus that causes a range of pulmonary diseases, some of which are characterised by fungal persistence such as is observed in cystic fibrosis (CF) patients. Creation of genetic variation is critical for A. fumigatus to adapt to the lung environment, but biofilm formation, especially in CF patients, may preclude mutational supply in A. fumigatus due to its confinement to the hyphal morphotype. We tested our hypothesis that genetic variation is created through parasexual recombination in chronic biofilms by phenotypic and genetic analysis of A. fumigatus isolates cultured from different origins.As diploids are the hallmark of parasex, we screened 799 A. fumigatus isolates obtained from patients with CF, chronic pulmonary lung disease and acute invasive aspergillosis, and from the environment for spore size. Benomyl sensitivity, nuclear content measurements through fluorescence-activated cell sorting and scanning electron microscopy were used to confirm the diploid state of large size spores. Whole genome sequencing was used to characterise diploid-associated genetic variation.We identified 11 diploids in isolates recovered from six of 11 (55%) CF patients and from one of 24 (4%) chronic aspergillosis patients, but not in 368 isolates from patients with acute Aspergillus infection and the environment. Diploid formation was associated with accumulation of mutations and variable haploid offspring including a voriconazole-resistant isolate.Parasexual recombination allows A. fumigatus to adapt and persist in CF patients, and plays a role in azole resistance development. Our findings are highly significant for understanding the genetics and biology of A. fumigatus in the human lung.

Dispersal of Arbuscular Mycorrhizal Fungi: Evidence and Insights for Ecological Studies.

Dispersal is a critical ecological process that modulates gene flow and contributes to the maintenance of genetic and taxonomic diversity within ecosystems. Despite an increasing global understanding of the arbuscular mycorrhizal (AM) fungal diversity, distribution and prevalence in different biomes, we have largely ignored the main dispersal mechanisms of these organisms. To provide a geographical and scientific overview of the available data, we systematically searched for the direct evidence on the AM fungal dispersal agents (abiotic and biotic) and different propagule types (i.e. spores, extraradical hyphae or colonized root fragments). We show that the available data (37 articles) on AM fungal dispersal originates mostly from North America, from temperate ecosystems, from biotic dispersal agents (small mammals) and AM fungal spores as propagule type. Much lesser evidence exists from South American, Asian and African tropical systems and other dispersers such as large-bodied birds and mammals and non-spore propagule types. We did not find strong evidence that spore size varies across dispersal agents, but wind and large animals seem to be more efficient dispersers. However, the data is still too scarce to draw firm conclusions from this finding. We further discuss and propose critical research questions and potential approaches to advance the understanding of the ecology of AM fungi dispersal.

No bull: dung-dwelling mushrooms show reproductive trait syndromes different from their non-coprophilous allies

The spores of most coprophilous mushrooms require passage through a mammalian gut. Guts and faeces constitute a chemically and microbially aggressive environment. Hence, the spores need to be armed, e.g. by melanisation and thick walls, possibly leading to large spores due to volume constraints. Conversely, litter is a less stressful substrate that may become colonised by mushrooms with less fortified spores. Compared with litter, dung pats are spatially constrained, which limits mycelial growth. Small mycelia can only produce small fruit bodies. Moreover, on quickly perishing faeces, fruiting takes place under fierce competition by microbes and dung-dwelling invertebrates. Therefore, coprophilous mushrooms are forced to mature fast, implying small fruit bodies as well. Competition in spatially less constrained litter substrates can be pronounced but should not lead to quick nutrient depletion as in dung, hence would allow for mushroom assemblages with on average larger fruit bodies. To find evidence for our assumptions, we compiled a database of fruit body and spore sizes of mushroom genera which contain coprophilous species, comprising 633 (including ca. 20% coprophilous) species across 18 genera worldwide. The data set was subjected to a phylogenetically informed statistical analysis. Our hypotheses were confirmed though the selective pressure of the faecal environment appears to be more forceful on spores considering the fact that the mean spore size differences are more pronounced than differences in mean fruit body size. It would be worthwhile to further elucidate this phenomenon and the coprophilous trait syndrome in general with molecular methods.

Conidial heat resistance of various strains of the food spoilage fungus Paecilomyces variotii correlates with mean spore size, spore shape and size distribution

Contamination by spores is often the cause of fungal food spoilage. Some distinct strains of the food spoilage fungus Paecilomyces variotii are able to produce airborne conidia that are more heat-resistant than similar species. These ellipsoid asexual spores can vary in size between strains, but also within strains. Here, we compared four measurement techniques to measure conidia size and distribution of five heat-sensitive and five heat-resistant P. variotii strains. Light microscopy (LM), Scanning Electron Microscopy (SEM) and Coulter Counter (CC) were used to measure and compare the spherical equivalent diameter, while CC and flow cytometry were used to study spore size distributions. The flow cytometry data was useful to study spore size distributions, but only relative spore sizes were obtained. There was no statistic difference between the method used of spore size measurement between LM, SEM and CC, but spore size was significantly different between strains with a 2.4-fold volume difference between the extremes. Various size distribution and shape parameters were correlated with conidial heat resistance. We found significant correlations in mean spore size, aspect ratio, roundness and skewness in relation to heat resistance, which suggests that these parameters are indicative for the conidial heat resistance of a P. variotii strain.

Spore development during capsule maturation of three Riccia species

Berg, C. & Pöltl, M. 2020. Spore development during capsule maturation of three Riccia species. – Herzogia 33: 179 –187.Ricciaspores develop during sporophyte growing and maturation. In young capsules, the spores have not yet archived their final size, color and ornamentation. These are important features for the determination. We ask, at which stage of development the spores show their final features, and how bryologists can recognize this. With the help of light microscope photography, we measure and describe spores taken from young, mature and open capsules. Young capsules exhibit a lighter color and do not bulge above the thallus surface. Riccia-spores reach their final size, ornamentation and color in mature capsules. Mature capsules are mostly dark, and bulge above the thallus surface. They remain globose after drying as herbarium specimens. According to our study, the spores of such capsules show the same final features as spores in open capsules. They are suitable to measure spore size and examine the characteristic ornamentation and color of the exospore.

The new truffle genus Babosia and a new species of Stouffera from semiarid grasslands of Hungary

ABSTRACT Truffles with distinct morphological and anatomical features were collected during a study of hypogeous fungi of semiarid sandy grasslands of the Great Hungarian Plain in Hungary, representing the westernmost localities of the Eurasian steppe belt. None of the ascomata were collected near ectomycorrhizal plant species, and none were identified as ectomycorrhizal during previous surveys in the collection area. We studied morphoanatomical characteristics of these truffles with light and scanning electron microscopy and investigated their phylogenetic positions based on analyses of different nuclear loci. The truffles were found to represent two novel lineages that grouped with the Marcelleina-Peziza gerardii clade of the Pezizaceae. One formed a distinct lineage, for which we propose a new genus Babosia with a new species Babosia variospora characterized by diverse spore ornamentation varying even within one ascus. The truffles in the other lineage clustered with the rarely collected American truffle Stouffera longii and share with it similar spore ornamentation and habitat features. However, our material differs from S. longii by geographic origin, the quick and strong coloration of the ascomata to dark gray at cut surface or bruised area, varying spore number in asci, and smaller spore size; thus, we describe it as a new species, Stouffera gilkeyae.

Four Species of True Morels (Morchella) Recorded from Poonch District (Azad Jammu and Kashmir)

A study was carried out in three administrative units (tehsils) of Poonch district of Azad Jammu and Kasmir (AJK) state to record the presence of true morels belonging to genus Morchella of class Ascomycetes. A periodic random survey was carried out during the year 2015-16. Distribution of four species of morels Morchella esculenta (40%), M. elata (30%), M. deliciosa (20%) and M. semilibera (10%) was recorded during survey period from February 15 to March 30. During rest of months of survey period no morel was observed in the same locations. The temperature during collection ranged between 3-7 °C. Morels were found growing under plant canopies, tree shades and on disturbed grass lands. To isolate, morels were dug out with the help of shovel and spade. Detailed macro and microscopic features such as stipe, pileus, spore shape and size were recorded. The minimum pileus diameter measured was about 1.0-2.5 cm in M. semilibera, while the maximum measurement of pileus diameter was 7.0-7.5 cm in M. elata. The minimum stipe length was about 1.5-5.0 cm in M. deliciosa, while the maximum measurement was observed 7.0-10.0 cm in M. semilibera. In addition, spore print (yellow, pale and black) was observed, while the maximum spore size was found in case of M. semilibera. The findings of this study showed the presence of four different species of morels in Poonch district of Azad Jammu and Kashmir.

Morphologically similar but not closely related: the long-spored species of Subulicystidium (Trechisporales, Basidiomycota)

Species boundaries and geographic distribution of corticioid fungi (resupinate Basidiomycota) are often poorly known. Our recent study on Subulicystidium showed that species diversity in this genus is at least twice as high as previously recognized. This re-estimation of the species diversity was based on a study of only a part of the genus. The present study sheds light on molecular and morphological diversity of three more species. We generated 27 ITS and 24 28S nuclear ribosomal DNA sequences from 49 specimens labelled as Subulicystidium cochleum, S. longisporum and S. perlongisporum and collected in distant geographic localities. We assessed pairwise dissimilarities and phylogenetic relationships of DNA sequences with Bayesian and maximum likelihood methods. We correlated phylogenetic information with morphological data on spores and cystidia. We found that the three species are not closely related, despite their similarity in spore shape and size. In one of the species, S. perlongisporum, we detected the presence of two sympatric lineages. These lineages are not morphologically distinct, except for a small difference in the mean length of cystidia. Our study provides a further example of transoceanic species distribution in Agaricomycetes.

Global mycorrhizal fungal range sizes vary within and among mycorrhizal guilds but are not correlated with dispersal traits

AbstractAimMycorrhizal fungi associate with the majority of plant species with large consequences on ecosystem nutrient, carbon and water cycling. Two main types of mycorrhizal fungi, arbuscular mycorrhizal (AM) fungi and ectomycorrhizal (EM) fungi, dominate terrestrial ecosystems. Most global distribution modelling of AM and EM associations describe the distribution of AM and EM plants, and not fungi directly. However, significant functional trait variation occurs within AM and EM fungal guilds. Therefore, modelling range sizes and determinants of these ranges of fungi directly is likely to create spatial maps that are a better proxy of ecosystem function than guild‐level lumping of AM and EM plant distributions.LocationGlobal.TaxaArbuscular mycorrhizal and ectomycorrhizal fungi.MethodsHere I calculated the ranges of 164 AM and 67 EM fungal taxa at the global scale and related range sizes to differences in spore sizes as a proxy of dispersal potential. If dispersal limitation affects range sizes, I expected that EM fungi with smaller spores would have larger ranges than AM fungi with larger spores. If spore size was not related to range size, this would indicate factors other than passive dispersal control global mycorrhizal fungal ranges.ResultsOverall, AM fungal taxa had larger ranges than EM fungal taxa. AM fungi also had larger spore sizes than EM fungi. Range sizes within both AM and EM fungal taxa were phylogenetically conserved; closely related AM and EM fungi have similar range sizes. Closely related EM fungi also had similar spore sizes. However, spore size was not related to range size for either mycorrhizal fungal guild after phylogenetic correction, except for EM fungi in the Northern hemisphere.Main ConclusionsThese findings provide evidence that range size for both mycorrhizal fungal guilds is for the most part not determined by dispersal limitation, suggesting instead that environmental tolerance or plant host distributions determine mycorrhizal fungal ranges. Future surveys of the same plant species across environmental gradients will elucidate abiotic versus host plant influence on mycorrhizal fungal niches.

<p><strong><em>Urocystis piptatheri</em></strong><strong> sp. nov. (Urocystaceae), a new species of smut fungus on <em>Piptatherum laterale</em> (Poaceae) from Pakistan</strong></p>

A new species of smut fungi, Urocystis piptatheri is described from Kumrat Valley, Pakistan based on morphological characters and molecular phylogenetic analysis of nuclear ribosomal DNA comprising the internal transcribed spacer (ITS) regions along with large subunit (LSU). The new species is characterized by the large size of its spore balls, size and number of central spores, spore wall thickness, sori in leaves and by the host plant species (Piptatherum laterale). Phylogenetic analysis of nuclear ribosomal ITS and LSU nucleotide sequences confirmed the novelty of Urocystis piptatheri. A key for the identification of Urocystis species on Pipthatherum spp. is provided.