Mycologia最新文献

During scientific expeditions across the Qinghai-Tibetan Plateau, a group of Buellia species were frequently collected from alpine arid regions. These were characterized by having whitish chalky thalli, a surface covered with thick coarse pruina, a reddish-brown hypothecium, and the presence of xanthones. Detailed observations were made of specimen morphology and anatomy. Phylogenetic analysis was conducted based on four loci: the internal transcribed spacer of the rDNA (ITS), partial large subunit nuc rDNA region (28S), RNA polymerase II second largest subunit gene (rpb2), and β-tubulin gene (tubb). Three species, which formed a new distinct lineage within Buellia s.l. were confirmed as new to science: Buellia plana, B. elevata, and B. tibetana. This lineage is here referred to as the pruinocalcarea-group because of a species previously described that belongs to this group: B. pruinocalcarea. Species included in this group are closely related to Tetramelas; the group also has affinities to the epigaea-group and subalbula-group. Detailed descriptions, photographs of the new species, and a key to the species are provided.

The Oomycetes are renowned for harboring several important pathogenic species, such as Phytophthora and Pythium. In this study, we described two species: a non-papillate, homothallic Phytophthora species and a papillate, asexual Phytopythium species. The strains were collected from the subtropical island of Japan and a warm-temperate forest in China, respectively. Neither strain could be fully assigned to any known taxon, so they were characterized through morphological studies and multigene phylogenetic analyses. The phylogenetic relationships were determined using four loci, namely, the internal transcribed spacer region (ITS-rDNA), cytochrome c oxidase gene (cox1), TigA gene fusion protein (tigA), and the ras-related protein (ypt1), for Phytophthora and five loci, namely, ITS-rDNA, 28S ribosomal DNA (28S-rDNA), cox1, cox2, and the beta-tubulin (β-tub) gene, for Phytopythium. Furthermore, the mitochondrial genome of the new Phytophthora species was sequenced and annotated, revealing a unique gene arrangement compared with related Phytophthora species. Based on these distinct morphological features and taxonomic status, we formally describe the two species as new species. Detailed micromorphological descriptions, illustrations, and molecular DNA data are provided to support their taxonomic classification.

Taphrinomycotina, a subphylum of the phylum Ascomycota, comprises fungi with diverse morphologies and ecologies. Saitoella and Savitreella are genera of red-colored yeasts within Taphrinomycotina, but their precise phylogenetic positions have remained controversial. In this study, we sequenced the whole genomes of Saitoella coloradoensis and Savitreella phatthalungensis in order to elucidate their phylogenetic relationships using a phylogenomic approach based on chromosome-level genome assemblies generated by long-read sequencing technologies. Our phylogenetic analyses suggest that Saitoella is distinct from all currently described classes within Taphrinomycotina, whereas Savitreella seems to belong to the class Taphrinomycetes. Furthermore, Saitoella shares high average amino acid identity with all other classes in Taphrinomycotina, suggesting that it retains ancient gene sequences. Our findings enable us to propose a new class, order, and family-namely, Saitoellomycetes, Saitoellales, and Saitoellaceae-automatically typified by the genus Saitoella. Our chromosome-level assembly reveals that Saitoella coloradoensis possesses 38 chromosomes, the highest number of chromosomes among fungi reported to date. We also identify structural differences between two Saitoella species and a chromosome structure lacking the canonical palindromic centromeric repeat sequence.

The Trichiaceae, a major family of Myxomycetes, has undergone significant taxonomic revision in recent years. Yet, systematic research on this group in China remains limited, resulting in outdated taxonomy and persistent gaps in species diversity and biogeographic understanding. To resolve this, this study performed a comprehensive revision of Chinese Trichiaceae, combining morphological analysis (light and scanning electron microscopy) and multigene phylogenetics (nuclear 18S rDNA, elongation factor-1 alpha, and mitochondrial small subunit ribosomal RNA) based on specimens deposited in the Herbarium of Fungi at Nanjing Normal University and the Herbarium Mycologicum, Academiae Sinicae. We also synthesized published literature to compile an updated checklist of 65 species with detailed Chinese distribution records. This study describes two new species (Metatrichia scintillans and Trichia coronata), revises one species (Oligonema latitubulare), and reports four new records for China (Ophiotheca calongei, Trichia acetocorticola, Trichia pinicola, and Trichia taeniifila). This study addresses key knowledge gaps in China's myxomycete biota and provides a standardized framework for future research on Trichiaceae biodiversity and taxonomy.

Fire is a common disturbance that structures terrestrial ecosystems. Since climate change models predict increases in fire frequency, it is important to study how changes in fire regime influence plant fuel-related above- and belowground ecosystem components. Due to their role in plant fuel production, arbuscular mycorrhizal (AM) fungal spore communities and symbioses with plants are invaluable for understanding how changes in fire regime influence belowground communities and alter fuel-related above- and belowground processes such as plant growth. With a greenhouse experiment, we tested how variation in fire frequency and history influenced AM fungal community composition, traits, and their interactions with host plants by manipulating fire regimes over three successive generations of AM fungi and Rudbeckia hirta plants. We found that fire frequency effects on spore traits such as pigmentation and sporulation mediated changes in AM fungal spore communities, but these effects took time to develop and were associated with reduced plant growth. This demonstrates that increases in fire frequency can alter the fire-fuel feedbacks that underlie pyrophilic ecosystems.

Mexican dry ecosystems, mainly tropical dry forests, harbor a vast and largely undiscovered fungal diversity. The stalked puffballs of Tulostoma (Basidiomycota: Agaricales) are highly cryptic, necessitating detailed and expert examination to accurately distinguish the species. A revision of the MEXU national fungarium and recent sampled specimens revealed fruiting bodies that did not match any known species. This led us to propose T. parvirufula and T. chamelensis as new species. Six collections were morphologically characterized using two microscopy techniques: light and scanning electron microscopy. DNA was extracted, the nuc rDNA internal transcribed spacer region ITS15.8S-ITS2 (ITS barcode) and D1-D2 domains of the nuc 28S rDNA were amplified and sequenced. Phylogenetic analyses were conducted using maximum likelihood and Bayesian inference methods, incorporating sequences from previous studies. Tulostoma chamelensis is distinguished by its medium-sized spore sac, a hyphal exoperidium that persists at the base, a tubular ostiole, and verrucose to subreticulate basidiospores. Tulostoma parvirufula is characterized by minute spore sacs, a tubular ostiole, a hyphal exoperidium, a reddish-brown endoperidium, and spiny basidiospores. Phylogenetic analyses place both species in a sister clade to clade 11, alongside other taxa with tubular ostioles and coarsely ornamented basidiospores, further expanding our understanding of the Tulostoma genus and its diversity in dry ecosystems.

The eastern larch beetle (Dendroctonus simplex LeConte) is a native and historically nonaggressive inhabitant of Larix laricina trees in North America. Since 2001, however, D. simplex has experienced an uncharacteristic and prolonged outbreak that has impacted trees on approximately 90% of the L. laricina forests in Minnesota. To investigate the fungal communities within D. simplex galleries during this outbreak, we isolated fungi from 56 D. simplex-infested trees across seven sites in Minnesota. We recovered 45 fungal species, including four new species in the order Ophiostomatales, proposed as Graphilbum insulare, sp. nov., Ophiostoma itasca, sp. nov., Ophiostoma minnesotense, sp. nov., and Ophiostoma pseudoips, sp. nov. Additionally, based on phylogenetics and morphological traits, we recommend a new taxonomic classification for Leptographium simplex, comb. nov. previously described as Graphium simplex from D. simplex galleries in Vermont, USA. At the community level, most isolates were in the phylum Ascomycota (82% of the total relative abundance), followed by Basidiomycota (12%). The most frequently isolated orders were Ophiostomatales (59% of the total relative abundance), Hypocreales (9%), and Pleosporales (8%). One species, Grosmannia americana, accounted for more than half of all isolates recovered. These results improve our understanding of the fungi associated with a bark beetle outbreak and an understudied tree species.

A novel Synchytrium species, Synchytrium gangeticum, sp. nov. (Chytridiomycota: Synchytriaceae), is described as the causal agent of wart disease in Andrographis paniculata (a medicinally important herb) in northern India. Synchytrium gangeticum exhibits host specificity toward A. paniculata, inducing the formation of small, raised, red/brown galls on leaves and stems, with rapid spread observed during early rainy seasons. The microscopic analysis revealed distinct spore morphology and gall development, characteristic of a long-cycled Synchytrium species. It is distinguished by unique resting spore dimensions (90-170 µm) and sporangium size (40-70 µm) and produces uniflagellate zoospores measuring 1-3 µm. Phylogenetic analyses, based on rDNA gene cluster (internal transcribed spacer [ITS], 18S, and 28S), positioned S. gangeticum closest to Synchytrium collapsum, but with significant morphological, and genetic divergence. This study presents the first comprehensive description of a Synchytrium species pathogenic to A. paniculata, providing insights into its host specificity, life cycle, and phylogenetic relationship within the genus.

The ash dieback pathogen (Hymenoscyphus fraxineus) is a major threat to ash populations across Europe. This study examined how strain handling can affect in vitro growth and in planta virulence of H. fraxineus, with implications for maintaining culture collections for laboratory and greenhouse studies. Ten H. fraxineus strains were selected: seven from a strain collection and three newly isolated individuals. Growth characteristics of the strains were evaluated in vitro on malt extract agar (MEA) and ash-amended malt extract agar (AMEA). Virulence was also investigated in planta following artificial inoculations into Fraxinus excelsior saplings. In vitro growth rate did not correlate with virulence in planta. The strains were subsequently reisolated to investigate changes in in vitro growth and in planta virulence due to reintroduction to the host. Reintroduction to the host led to increased virulence of strains in planta, including a significant increase in necrosis growth rate following two reintroductions. There was a significant increase in necrosis growth rate following two reintroductions to the host. These observations were more distinct in newly isolated strains previously cultured on AMEA. Moreover, more strains were virulent when previously cultured on AMEA, compared with MEA. These results indicate not only that strains of H. fraxineus from collections can be rejuvenated, but also that the virulence of newly isolated strains can be increased. Overall, these results provide insights into the impacts of laboratory protocols on in vitro growth characteristics and in planta virulence of H. fraxineus strains. Furthermore, these results provide methodological opportunities for maintaining growth characteristics in strains intended for long-term use and storage in collections, as well as a possible method for rejuvenating strain virulence.

We investigated the extent of recombination among isolates of Beauveria bassiana s.l. to assess whether gene flow occurs among them in nature and infer whether non-outcrossing populations may represent cryptic species. We sequenced and assembled genomes of 14 isolates collected from soil in Queensland, Australia, and each was genotyped at their mating type locus. We reconstructed a phylogeny from sequences of B. bassiana available on the National Center for Biotechnology Information Sequence Read Archive (NCBI SRA) database and those generated in this study. The isolates from Queensland sequenced in this study form a distinct clade relative to the isolates from other countries on NCBI, and they separated into four genetic groups with high pairwise F_ST values between them. One of these groups had both MAT1-1 and MAT1-2 mating types, but the other three each had only a single mating type. We crossed isolates from the different genetic groups on Sabouraud dextrose agar yeast extract (SDAY) solid medium and used vegetative compatibility and the production of sexual structures as measures of whether sexual or parasexual recombination is likely to occur in nature. Vegetative compatibility was found within genetic groups when opposite mating types were crossed, with the production of synnemata and perithecia-like structures. However, sexual structures (perithecia, asci, or ascospores) did not develop. Isolates from the different genetic groups were not vegetatively compatible when crossed. We used analyses of linkage disequilibrium to test for evidence of past recombination among the Queensland genetic groups. Two of them had low indices of association and were reticulate in network analyses, which supports recombination (and therefore sexual or parasexual reproduction) within these two genetic groups, but we found no evidence for recombination among the four genetic groups. Our results indicate that B. bassiana is a diverse complex of multiple cryptic species.