Mycoscience最新文献

We hypothesised that cadmium exposure would hinder growth and secretion of carbon-degrading enzymes by mycorrhizal fungi, and that this would vary according to their tolerance to cadmium stress. The enzymes measured were β-Glucosidase, β-Xylosidase, β-D-cellubiosidase, N-acetyl-β-Glucosaminidase in three strains of ectomycorrhizal fungi Hebeloma subsaponaceum, Scleroderma sp., Hebeloma sp. and a feremycorrhizal fungus Austroboletus occidentalis. Fungi were subjected to cadmium stress for 28 d (in modified Melin-Norkrans liquid medium). The results showed unanticipated differential response of enzyme activities among the fungal species, including potential hormesis effects. Austroboletus occidentalis showed an increase in enzyme activity under cadmium stress.

Developing high-content strains of L-ergothioneine (EGT), an antioxidant amino acid, is an important breeding target for tamogitake mushroom, Pleurotus cornucopiae var. citrinopileatus. We constructed a genetic linkage map based on segregation analysis of markers in 105 F1 progenies. The loci of 245 markers, including 10 AFLP markers, 195 Rad markers, 2 mating type factors, and 38 gene markers, were mapped. The map contained 12 linkage groups with a total genetic distance of 906.8 cM, and an average marker interval of 4.0 cM. The population from crossing between tester monokaryon and F1 progenies was used to characterize quantitative trait loci (QTL) for EGT content. With composite interval mapping (CIM) method, QTL of EGT content were found to be located in linkage group 10, having a Logarithm of the odds (LOD) score of 2.53 with a 10.1% contribution rate. Moreover, a single nucleotide polymorphism (SNP), A/T, was identified in a gene region of the genome in the neighborhood where the QTL peak existed. This SNP genotype was in good agreement with the EGT phenotypes of each strain in the both QTL population and wild population. Thus, this SNP would have great potential value to use the marker-assisted selection (MAS) for this mushroom with high EGT content.

The resinicolous fungi Sarea difformis and S. resinae (Sareomycetes) were taxonomically revised on the basis of morphological observations and phylogenetic analyses of the nucleotide sequences of the nSSU-LSU-rpb1-rpb2-mtSSU genes. The results of phylogenetic analyses show that S. difformis and S. resinae are grouped with members of Xylonomycetes. According to the results of phylogenetic analyses and their sexual and asexual morphs resemblance, Sareomycetes is synonymized with Xylonomycetes. Although Tromera has been considered a synonym of Sarea based on the superficial resemblance of the sexual morph, we show that they are distinct genera and Tromera should be resurrected to accommodate T. resinae (= S. resinae). Xylonomycetes was morphologically re-circumscribed to comprise a single family (Xylonaceae) with four genera (Sarea, Trinosporium, Tromera, and Xylona) sharing an endophytic or plant saprobic stage in their lifecycle, ascostroma-type ascomata with paraphysoid, Lecanora-type bitunicate asci, and pycnidial asexual morphs. Phylogenetic analyses based on ITS sequences and environmental DNA (eDNA) implied a worldwide distribution of the species. Although Symbiotaphrinales has been treated as a member of Xylonomycetes in previous studies, it was shown to be phylogenetically, morphologically, and ecologically distinct. We, therefore, treated Symbiotaphrinales as Pezizomycotina incertae sedis.

A novel species of Tricholoma section Tricholoma, namely, T. olivaceonigrum, is described and illustrated based on samples found in an oak woods dominated by Quercus myrsinifolia, an evergreen oak, in Tottori Prefecture, western Japan. It is characterized by a conic-umbonate, dark-greenish olivaceous pileus with blackish innate fibrils; a whitish silky-fibrillose stipe, often faintly tinted pale yellow and with a narrowed subpointed base; subglobose to broadly elliptic spores; and fruiting in early winter. Phylogenetic analysis targeting the internal transcribed spacer region of the ribosomal RNA gene revealed that T. olivaceonigrum forms a well-supported clade sister to T. portentosum. Other morphologically and phylogenetically closely related species of the section Tricholoma are discussed.

A new luminescent lignicolous fungal species, Mycena cristinae sp. nov., is proposed from the Central Amazon forest. This is unique and supported by morphological evaluation along with LSU- and ITS-based phylogenetic analyses. The basidiomata have mostly fuscous olivaceous brown pileus, adnate to subdecurrent and distant lamellae, and stipe with slightly bulbous base (basal mycelium absent). It also has inamyloid and/or weakly amyloid basidiospores, ramose cheilocystidia and a pileipellis composed of an aerated tangle of slender, diverticulate hyphae forming a coralloid pellicle overlaying the hypodermium. The luminescence is evident in the basidiomata (especially the stipe) and in the mycelium on the substrate. The LSU phylogenetic trees reveal that M. cristinae is sister to M. coralliformis within the Mycenaceae clade. In the ITS trees, it forms a unique lineage grouping with undetermined Mycena taxa. Morphological data support M. cristinae as a different species compared to previously described taxa.

Morphological characters and multi-gene phylogenetic analyses were used to identify Retiboletus specimens collected in northern Thailand. Retiboletus brevibasidiatus is described as new to science, whereas R. fuscus and R. nigrogriseus are reported for the first time from Thailand. Retiboletus brevibasidiatus produces medium-sized basidiomes, with a dark blonde to clay pileus and densely reticulate stipe mostly on the upper part with pale yellow to chrome yellow basal mycelium. It is difficult to separate R. brevibasidiatus from other closely related species on the basis of macroscopic characters. However, the new species can be distinguished by microscopic characters, mostly the shorter basidia. The macro- and micro-morphology of the R. fuscus and R. nigrogriseus collections from Thailand fit well with the previous descriptions of materials from China and Japan. Detailed descriptions, molecular phylogeny, and illustrations of the three species are provided.

In order to elucidate the lifecycle of Coprinus comatus, we examined the number of nuclei in basidiospores, hyphal cells and oidia. Basidiospores isolated from the fruiting bodies of four Japanese strains were binucleate. In both primary and secondary mycelia, most of the cells were binucleate. In addition, oidia and oidiophores were observed for the first time in this mushroom and most of the oidia were binucleate. Based on these results, the lifecycle of C. comatus was inferred to be as follows. A homokaryotic binucleate basidiospore germinates and produces homokaryotic binucleate hyphae. After mating between compatible homokaryotic binucleate hyphae, a heterokaryotic binucleate secondary mycelium is produced. If environmental conditions are suitable for fruiting, homokaryotic binucleate basidiospores in the fruiting body are produced.

During surveys conducted on freshwater fungi from Vietnam, a new aquatic anamorphic fungus was isolated from decaying leaves in Vietnam. The fungus produced phialidic, swollen conidiophore and conidiogenous cells with one-celled conidia with four very tiny lobes. Based on its conidial development and other morphological characteristics, we confirmed that this is a novel fungus and described it as P. ambigua sp. nov. Phylogenetic analyses of P. ambigua based on the LSU nrDNA sequences showed that this fungus clusters in a single clade with the two known Polylobatispora spp. with 97% bootstrap value which is sister with Pseudoprobiscisporaceae. The Polylobatispora clade is nested in the Attracrosporales, Sordariomycetes. Furthermore, in this study two known species of Polylobatispora (P. deltoidea and P. quinquecornuta) were also isolated and illustrated.

Erysiphe actinidiicola on Actinidia polygama is described based on morphological and molecular data. Erysiphe actinidiicola is distinguished from E. actinidiae var. actinidiae by having irregularly to dichotomously branched chasmothecial appendages, larger chasmothecia sizes and numbers of asci per chasmothecium. Molecular analyses indicated that this species forms a clade separated from E. actinidiae var. actinidiae. An epitype is proposed for E. actinidiae var. actinidiae with ex-epitype sequences. A powdery mildew found on Limonium tetragonum is tentatively described as Erysiphe sp. This species is distinguished from E. limonii, a powdery mildew on Limonium spp., based on the DNA sequence differences in the 28S rDNA and internal transcribed spacer region as well as the morphological differences in the length of the conidiophores. This is the first record of powdery mildew on L. tetragonum in the world.

Helotiales is one of the most diverse groups of apothecial ascomycetes, including 3000-4000 taxa. Recent progress in the systematics, ecology, and their applications through research is herein reviewed based on the experiences of the author with a special emphasis on activities in Japan. In the past 30 y, more than 50 helotialean taxa have been added to the mycobiota of Japan, including new taxa. With the advent of molecular phylogeny, some families have been revisited, such as members with stroma (Sclerotiniaceae and Rutstroemiaceae) or hairs (Hyaloscyphaceae and Lachnaceae). Although the monophyly of Helotiales has not yet been demonstrated, our understanding of its phylogeny has greatly advanced. The unexpected ecological nature represented by endophytism has been revealed through barcoding and other molecular techniques. The research history of ash dieback is also reviewed, and the endophytism/saprophytism of the pathogen on its original host is discussed. Drug discoveries within Helotiales are reviewed, and successful examples are presented. As future perspectives, both the cumulation of occurrence and sequence data of Helotiales is greatly encouraged to elucidate this important group of fungi.