Aroramyces sinensis is described as new to science from subtropical region of southwestern China. Molecular and morphological characters separate this new hypogeous species from other existing taxa in the genus Aroramyces. Phylogenetic analyses based on partial nuc 28S rDNA (LSU) and translation elongation factor 1-α (tef1) sequences show that A. sinensis is closely related to A. gelatinosporus. This serves as the first report of Aroramyces from Asia. In addition, we provide a worldwide key to all recognized Aroramyces species.
Production of sterigmatocystin (ST) in Aspergillus nidulans involves the ST biosynthetic gene cluster, which has been considered to comprise 26 genes. However, functions of several genes within this cluster remain unclear. In this study, we investigated the role of the stcX gene in ST biosynthesis. As the open reading frame of stcX has been undefined, we deleted three putative genes adjacent to stcW simultaneously. Deletion of the region did not significantly impact growth rate across various growth conditions compared to the control strain. Chemical analyses revealed no significant change in ST production in the deletion strain compared to the control. Furthermore, the three transcripts were largely undetectable during ST biosynthesis, and the expression of other ST cluster genes was unaffected by the deletion. Our results suggest that these genes are not essential for ST biosynthesis in A. nidulans, indicating that the cluster should be delineated to exclude stcX.
This study describes Parasarocladium yichunense, a new species of Hypocreales isolated from leaf cradles of Reynoutria japonica, which were constructed by the weevil Euops chinensis for oviposition and fungal cultivation. Its taxonomic position within the genus Parasarocladium was determined using an integrative approach combining morphological, cultural, and multi-locus analyses based on the ITS, LSU, ACT, tef1, and tub2 regions. Phylogenetically, P. yichunense forms a well-supported, distinct monophyletic clade sister to the clades comprising P. debruynii and P. dipikae. Parasarocladium yichunense differs from its phylogenetically close relative, P. debruynii, in exhibiting slower growth on culture media, longer conidiophores (up to 120 μm), longer phialidic conidiogenous cells (2.3-40 μm), and larger conidia [3-11.8(-13.4) × 1.5-4.6 μm]. This discovery expands the known diversity of Parasarocladium and contributes to the growing documentation of fungal symbionts in leaf-rolling weevil mutualisms.
Myxomycetes are amoeboid protists primarily found in forest ecosystems. However, their inhabitation and ecology on twig litter remain poorly understood. Therefore, myxomycete species richness and diversity in a forest, canopy tree species and types, and the microenvironmental factors influencing their distribution were assessed. In a natural mid-temperate forest of western Japan, twig litter was seasonally sampled on the forest floor under nine canopy trees selected by different tree types and large, long-lived trees. Using moist chamber cultures (MCs), twigs were incubated to induce myxomycete fruiting. As a result, 60% of the 380 MCs produced fruiting bodies of 33 myxomycete taxa from 21 genera. Ordination of 18 myxomycete communities using non-metric multidimensional scaling distinguished two seasonal groups. The arrangement of the communities was significantly correlated with environmental factors, such as twig pH, soil pH, and diameter at breast height. Large, long-lived trees had characteristically distinct ecological habitats for myxomycetes on twig litter. Members of Cribrariales and Trichiales were dominant on coniferous twigs, whereas Physarales dominated evergreen twigs. This study suggests that canopy trees shape myxomycete communities as a microhabitat in a forest ecosystem, and a mid-temperate forest maintains a high species diversity of myxomycetes, making it an important biodiversity hotspot.
Spermogonia and aecia were found on Persicaria odorata subsp. conspicua (Polygonaceae) in a reed field of Lake Kasumigaura, Ibaraki, Japan. Near these plants, telia appeared to be Puccinia trabutii var. abei, of which the other spore stages were unknown, were found on culms of Phragmites australis. Inoculation experiments using basidiospores and aeciospores demonstrated that the two rust fungi were conspecific and the species was a heteroecious macrocyclic species of Puccinia. In addition to telia, an uredinial stage of the rust species was found on Ph. australis in the field observation and the inoculation experiments with aeciospores. Based on morphological observation including type specimens, the rust species was identified as P. abei. Characteristics of all the spore stages were described.
Mexico hosts a wide diversity of plant species, which is reflected in the high number of powdery mildew species present in the country. Nevertheless, many of them have not yet been detected and are often undescribed. The present work provides records of 13 species belonging to the genus Erysiphe (including sect. Erysiphe, sect. Microsphaera, and sect. Uncinula) from Mexico. In most cases, only asexual morphs have been found, which require molecular phylogenetic analyses based on ITS+28S rRNA sequences in addition to morphological examinations for accurate identifications. Five new reports: E. ampelopsidis, E. intermedia, E. peckii, E. rumicicola, and E. russellii and two new hosts for Mexico, viz., Casuarina equisetifolia (E. diffusa) and Lupinus elegans (E. intermedia), are amongst the new collections. The new species Erysiphe burserae, on Bursera kerberi and Bursera sp., is introduced, illustrated, and discussed.
Tuber japonicum is an ectomycorrhizal ascomycete fungus native to Japan that produces whitish truffles as one of their reproductive organs. In 2019, a truffle plantation was established in Kyoto Prefecture, Japan, by planting 14 seedlings of konara oak inoculated with two distinct inocula. In November 2022, the first ascocarp production was detected. To contribute to our understanding of the origin of the paternal gametes in this species, we determined the genotypes of 91 second-year ascocarps collected from the site in the autumn of 2023. All of the successfully-analyzed ascocarps possessed one of three maternal multilocus genotypes (MLGs), as identified by simple sequence repeat (SSR) marker analysis, two of which were identical to the paternal and maternal genotypes identified in ascocarps harvested the previous year. The number of paternal MLGs identified increased markedly from 2 in 2022 to 53 in 2023, 48 of which were found in only a single ascocarp. All paternal MLGs were either identical to a maternal one or a random recombination between them, indicating that the paternal gametes were derived from ascospores formed the previous year. Thus, this study clearly demonstrates that the majority of paternal mating partners in T. japonicum originate from the previous year's ascospores.
Understanding forest ecosystems involves knowing the role of organisms in dead trees. Myxomycetes that grow on dead trees disperse spores and reuse dead trees as substrate for reproduction. Compared to research on the interactions between myxomycetes and organisms other than Collembola (e.g., Acari, Diptera, and Coleoptera), studies on the interactions between myxomycetes and collembolans on dead trees are limited. To clarify the relationship between them, myxomycetes and nearby collembolans were collected through the aspiration method. This method allows the simultaneous collection of myxomycete fruiting bodies and collembolans. In the laboratory, the collected specimens were observed under a microscope, and the population density and spore-feeding behavior of collembola were analyzed and compared for each myxomycete. In our study, we identified ten families of collembola residing among myxomycetes on dead trees at the collection site. Notably, eight of these families were observed to consume spores and various components of the fruiting bodies of myxomycetes. Additionally, we conducted an analysis of the interrelationships among three species of myxomycetes, focusing on variations in collembolan populations and their feeding rates. This research represents the first quantitative investigation into the relationship between myxomycetes and collembolans, employing field-based observations and collections to yield our findings.
The sake industry continues to evolve in response to consumer demand for novel flavor profiles and fermentation characteristics. However, the genetic and phenotypic diversities of kuratsuki sake yeasts (brewery-specific landraces), which are critical for regional uniqueness and flavor development, remain poorly understood because of limited research and the inherent difficulty of distinguishing these indigenous strains from industrial counterparts. Using molecular biology techniques developed in our laboratory, we successfully isolated indigenous yeast strains from sake breweries in Niigata Prefecture. Subsequent sake fermentation analysis demonstrated substantial phenotypic diversity among these isolates, revealing a wide range of fermentation performance and distinct flavor compound profiles. These findings confirm the continued presence of diverse kuratsuki sake yeasts with industrial potential and highlight their practical applicability in broadening the flavor profiles of sake products.
A new species, Auriscalpium flabellatum (Auriscalpiaceae), is described from Japan. While A. orientale, which typically grows on conifer cones, is the only known species of Auriscalpium in Japan, A. flabellatum produces basidiomata directly from soil. The basidiocarps are small, laterally stipitate, and have fan-shaped pilei with fimbriate margins. Morphological examination revealed distinctive features, including amyloid basidiospores that are subglobose to broadly elliptic, and a dimitic hyphal system with gloeocystidia. Molecular phylogenetic analyses based on the internal transcribed spacer (ITS) region of rDNA placed this species within the Auriscalpium-Gloiodon clade. Clear morphological and ecological differences from known species support the recognition of A. flabellatum as a new species based on substrate specificity, pileus morphology, and phylogenetic evidence.
In this study, by screening approximately 160 mushroom extracts for anti-Trichophyton activity, significant activity was found in the culture filtrate of the Auricularia heimuer TUFC 100803 strain. To purify the active compound, the strain was cultured in 2.0 L of malt liquid medium, and the culture filtrate was extracted with ethyl acetate. The resulting crude extract was fractionated by silica-gel chromatography and preparative thin-layer chromatography, and a pure active compound, designated heimuerol A, was successfully isolated. According to IUPAC nomenclature, the compound was identified as (1R,2R,5R)-2-(prop-1-en-2-yl)-6-oxabicyclo[3.1.0]hex-3-en-2-ol. Unlike terbinafine, which is used as both a topical and oral medication for tinea, heimuerol A lacks a nitrogen and possesses a structure containing an epoxide group and a five-membered ring. The minimum inhibitory concentration (MIC) of terbinafine-resistant strains was lower than that for wild-type strains when treated with heimuerol A. Furthermore, a mixture of heimuerol A and terbinafine exhibited activity at concentrations lower than their respective MICs. These findings suggest that heimuerol A inhibits ergosterol biosynthesis through a mechanism distinct from that of terbinafine.
Amanita clarisquamosa and A. avellaneosquamosa, both of which belong to the section Amidella, were described in 1933 in Nopporo, Hokkaido, Japan. Owing to large intraspecific variation and high interspecific resemblance in morphology, species delimitation and identification of section Amidella members is difficult. This also applies to the two focal species. Furthermore, the minimality of the original descriptions of A. clarisquamosa and A. avellaneosquamosa exacerbates this problem. For reliable identification, detailed morphological and molecular information of reliably identified specimens, hopefully type specimens is required. However, further morphological and molecular information cannot be obtained from the degraded type specimens. In this study, new specimens that showed morphological and molecular matches with A. clarisquamosa and A. avellaneosquamosa were obtained from Nopporo and the surrounding areas of Hokkaido. Detailed morphology and barcoding region sequences of these specimens were recorded. Importantly, the newly collected specimens showed morphological and molecular mismatches with previously reported A. clarisquamosa or A. avellaneosquamosa specimens. This indicated that specimens previously identified as these two species might have included misidentifications. Overall, the study results suggest a need for reconfirmation of species within the section Amidella.
Mold contamination in library and museum collections poses risks to both cultural heritage and human health. This study examined fungal flora on books stored under controlled environmental conditions (temperature <20 °C, relative humidity <50%) in The University Museum, The University of Tokyo. Both culture-dependent methods and DNA-based metabarcoding targeting the internal transcribed spacer 2 region were used. DNA analysis revealed that Aspergillus halophilicus accounted for over 90% of the sequences from six books. In contrast, culture-based methods using standard media (e.g., PDA, DG18, M40Y) primarily isolated species such as Aspergillus, Penicillium, and Cladosporium, but not A. halophilicus. However, cultivation on CzA supplemented with 70% sucrose at lower temperatures enabled successful isolation of A. halophilicus from one sample. The strain was identified based on morphological features and β-tubulin gene analysis. These findings demonstrate a notable discrepancy between molecular and culture-based results, underscoring the limitations of conventional media for detecting xerophilic fungi in dry environments. The study suggests that desiccation-tolerant species like A. halophilicus can thrive even under strict storage controls and may evade standard integrated pest management (IPM) protocols. To better assess fungal risks in preservation settings, combining improved media with DNA-based methods is essential.
A new anther smut fungus, Microbotryum crypticum is described based on specimens collected from the Japanese endemic plant, Silene miqueliana (Caryophyllaceae) in Osaka Prefecture, as well as from herbarium specimens of S. miqueliana preserved at the National Museum of Nature and Science (TNS) in Japan. Microbotryum crypticum is phylogenetically distinct from other anther smut fungi reported on Silene species and has relatively small spores compared to previously described Microbotryum species. Host preference further supports this new species. The presence of infected S. miqueliana plants in both herbarium and fresh specimens suggests that M. crypticum is widely distributed in Japan.
In regions of cryosphere, plants dormant under snow are attacked by snow mold pathogens, which include various fungal taxa (mainly oomycetes, ascomycetes and basidiomycetes). These fungi are well adapted to the environment with ambient temperatures fluctuating at around 0 °C. Their cold adaptation mechanisms differ at the phylum level. Oomycetous and basidiomycetous snow molds avoid freezing by intracellular host infection and ice-binding protein, respectively. Osmophily is another mechanism to cope with freezing for the ascomycete, Sclerotinia borealis. Thus diverse fungal taxa evolved snow molds to adapt to nival environments, illustrating adaptive radiations by developing cold tolerance and selecting host organisms.
A new species, Micropsalliota subumbonata, is described and illustrated from tropical region of the Western Ghats of Maharashtra, India, and the phylogenetic placement is determined by using nrITS and nrLSU sequence data analyses. Micropsalliota subumbonata, is morphologically circumscribed by its campanulate to conical umbonate pileus, covered with greyish brown to reddish brown squamules, ellipsoid to subcymbiform basidiospores, and cylindrical, long narrow, capitate cheilocystidia with a ventricose base.
Three species of tricholomatoid dark blue Entoloma spp. from temperate forests in Japan are described as new to science. Entoloma obscurocyaneum and E. purpureobrunneolum show a dull dark blue pileus, with the former distinguished by the purple-brown suprapellis hyphae of the pileipellis and the latter by its light brown color. Entoloma quasicyanonigrum is similar to E. cyanonigrum but exhibits smaller basidiospores. Our phylogenetic analysis placed them within a moderately supported clade that generally shares the characteristics of having a hymeniderm-or palisadoderm-type pileipellis. To date, the sole tricholomatoid dark blue Entoloma documented from Japan is E. cyanonigrum. Because it was confirmed that the type specimen of E. cyanonigrum no longer exists, the original material, the colored drawing by Tsuguo Hongo, was designated as the lectotype, and E. cyanonigrum was redescribed based on Hongo's observation notes and our examination of herbarium specimens.
A new species, Micropsalliota subumbonata, is described and illustrated from tropical region of the Western Ghats of Maharashtra, India, and the phylogenetic placement is determined by using nrITS and nrLSU sequence data analyses. Micropsalliota subumbonata, is morphologically circumscribed by its campanulate to conical umbonate pileus, covered with greyish brown to reddish brown squamules, ellipsoid to subcymbiform basidiospores, and cylindrical, long narrow, capitate cheilocystidia with a ventricose base.
Suillus grevillei is an ectomycorrhizal fungus of larch that occurs widely throughout the Northern Hemisphere. According to its pileus color and geographic distributions, two closely related species are recognized: European S. grevillei that has a yellowish pileus and North American S. clintonianus that has a reddish pileus. Because specimens in eastern Eurasia are understudied, we incorporated basidioma collections from Japan and eastern Siberia to clarify the taxonomy and distribution of the S. grevillei complex in a global context. The multi-locus phylogeny assembled with four conservative loci (LSU, RPB1, RPB2, and TEF) revealed three monophyletic clades with strong branching support, one of which is described as a new species, S. orientalis. Morphologically, S. orientalis is distinguished from S. grevillei by its dark reddish-brown pileus and from S. clintonianus by having smaller spores and the absence of encrusted hyphae in the pileipellis. S. orientalis is distributed in eastern Eurasia, S. grevillei in Europe and eastern Asia, and S. clintonianus in North America. The multi-locus phylogeny of conservative DNA markers was more effective than rapidly evolving and highly variable ITS regions in recognizing closely related species within the S. grevillei complex.
The fungus genus Mycena is saprotrophic, but several lineages form orchid mycorrhizae or associate closely with plant roots. To elucidate which Mycena species form mycorrhizal associations with orchids, fungal isolates of five Mycena species (M. epipterygia, M. haematopus, M. polygramma, M. pura, and Mycena sp.) from four sections (Calodontes, Fragilipedes, Hygrocyboideae, and Lactipedes) were cultured with the seeds of mycoheterotrophic orchids, including Gastrodia confusa, G. elata, G. nipponica, and G. pubilabiata. All five Mycena species stimulated seed germination in all four Gastrodia species. Mycena haematopus and M. polygramma had a high affinity for Gastrodia and induced protocorm formation in all of them and tuberization in seedlings of two of them. Phylogenetic analyses indicated that Mycena species that associate with Gastrodia are dispersed throughout the genus and do not form a monophyletic group. Gastrodia species differ in fungal specificity, with G. confusa having a narrow specificity for specific Mycena species, whereas G. pubilabiata and G. nipponica have a broader specificity with multiple Mycena lineages and non-Mycena species, Cyanotrama gypsea and Collybiopsis dichroa. Our results imply that phylogenetically diverse Mycena taxa associate with Gastrodia species as orchid mycorrhizal fungi.
