Corticioid fungi form effused basidiomata with various hymenophore configurations, mostly on woody substrates, and they are presently classified into 15 orders in Agaricomycotina in the phylum Basidiomycota. In this review, the corticioid fungi of Japan are treated on the basis of the current classification system, and all currently known species are listed and classified by order. Japanese corticioid fungi number 442 species in 160 genera belonging to 14 orders. Analysis of the distribution of Japanese corticioid species reveals that 375 species (85% of the total) have wide distributions, and that the Japanese corticioid fungal flora is composed of species with diverse patterns of distribution. In the subtropical regions, 146 corticioid species belonging to 77 genera are listed, including 100 species from the Nansei Islands and 76 from the Ogasawara Islands. Although these two island groups are located at similar latitudes, they share only 30 corticioid species―21% of the total reported from the subtropical regions. Along with this summary of the current status, this study presents future directions for the taxonomic research of the Japanese corticioid fungi.

Primer bias toward Tulasnellaceae fungi during PCR is a known issue with metabarcoding analyses for the assessment of orchid mycorrhizal communities. However, this bias had not been evaluated for the fungal communities of epiphytic orchids, which account for 69% of all orchid species diversity. We compared the mycorrhizal communities detected using two primer pairs, a fungal universal primer pair (ITS86F/ITS4) and Tulasnella-specific primer pair (5.8STulngs/ITS4-Tul2), using a mock community of fungal isolates from epiphytic orchids and also environmental samples, including orchid roots and a tree bark tip from the host tree of an epiphytic orchid collected. The detected mycorrhizal communities differed widely depending on the primer pairs used. The fungal universal primer pair successfully identified Ceratobasidiaceae and Serendipitaceae fungi but did not reflect Tulasnellaceae diversity. Tulasnellaceae fungi were mainly detected using the Tulasnella-specific primer pair. These tendencies were observed in both the mock community and environmental samples. These results strongly suggest that the use of a Tulasnella-specific primer in combination with a fungal universal primer is essential for assessing the mycorrhizal communities of orchids through metabarcoding analysis, especially in epiphytic orchids. Our study contributes to further understanding of the diversity of mycorrhizal fungi in orchids.

The rust fungi (Pucciniales) that infect ferns, early diverging vascular plants, are neither “primitive” nor monophyletic, as once hypothesized. The neotropical fern pathogen, Puccinia lygodii (Pucciniaceae), specializes on species of Lygodium. Lygodium is believed to have evolved in a period ca. 211 mya, which is after the evolution of the temperate fern rust fungi that parasitize later diverged ferns. Puccinia lygodii is the only rust species in the genus Puccinia known to infect ferns, the majority of which infect flowering plants. In this study we examined multiple new and herbarium specimens of P. lygodii and reconstructed its phylogenetic history with data generated from the 28S nuclear rDNA repeat. Puccinia lygodii is the sister species to another neotropical fern rust, Desmella aneimiae (Pucciniaceae), which also infects early diverged leptosporangiate fern species, and the new combination D. lygodii is made. Interestingly, P. lygodii and D. aneimiae differ primarily in sorus structure, i.e., subepidermal in the former vs. suprastomatal in the latter fungus. Characters such as suprastomatal sori and probasidia that germinate without dormancy are now known to represent a suite of adaptations that have been derived multiple times within Pucciniales, most likely in response to tropical climates.

Fungi exhibit saprophytic, parasitic, and symbiotic lifestyles, and flexibly switching between them by the environmental changes and host conditions. However, only a few studies have elucidated the detailed changes in fungal DNA or morphology, including the formation of reproductive structures along with lifestyle switching. We hypothesized that Pyrenopeziza protrusa, which occurs abundantly and specifically on Magnolia obovata as a saprophyte, is also associated with living hosts and switches its lifestyles as part of its lifecycle. To elucidate this hypothesis, we periodically sampled the fresh/fallen leaves of M. obovata to observe the seasonal occurrence of reproductive structures for the isolation and detection/quantification of P. protrusa DNA with newly developed species-specific primers. The isolation frequency and amount of P. protrusa DNA drastically increased in the fresh leaves just before defoliation in autumn, but remained high in fallen leaves from autumn to spring. Abundant production of conidiomata and apothecia was also observed in the fallen leaves with increasing DNA content. These results clarified a large part of the lifecycle of P. protrusa, suggesting that the lifestyle is switched from symbiotic to saprophytic stage by significantly increasing the amount of DNA in response to host conditions according to the seasonal variations.

In this study, we isolated 741 wild budding yeast strains from the flowers of 45 rose cultivars growing in Fukuyama city, Hiroshima, Japan. Of these 741 strains, 21 were found to have high fermentation abilities in yeast extract-peptone-dextrose (YPD) medium. Four of the 21 strains were able to ferment bread dough to make bread. These yeasts were identified as Saccharomyces cerevisiae, Lachancea fermentati, Lachancea kluyveri, and a Torulaspora sp. based on DNA sequences from the 26S rDNA D1/D2 regions. The CO₂ production profiles of the bread dough generated by the rose yeasts were evaluated using a Fermograph. Saccharomyces cerevisiae FRY2915 exhibited the highest fermentation capacity. Furthermore, FRY2915 was able to ferment grape juice to produce wine, yielding an alcohol concentration of more than 12%. The four rose yeasts isolated during this study have the potential to produce various types of unique fermented foods, thus enhancing the value of the microbiota associated with rose flowers.

The phylogeny and taxonomy of Podosphaera filipendulae (including P. filipendulensis, syn. nov.) have been examined. Asian, European and North American collections were examined and the nucleotides sequences of their partial rDNA region were determined. In particular, the relationship between P. filipendulae and P. spiraeae was analysed. The results confirmed P. filipendulae and P. spiraeae as two separate, morphologically similar species. The phylogenetic analysis revealed a similar phylogeny to that of the host genera. Although ITS sequences retrieved from Asian, European and North American specimens of P. filipendulae on various Filipendula spp. are identical to sequences from P. macularis on hop, there is consistently one base substitution at the 5'-end of 28S rRNA gene between the species. This result provides evidence that the hop powdery mildew and P. filipendulae are biologically and morphologically clearly distinguished, and should be maintained as two separate species.

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.

Racodium therryanum is a snow mold causing snow blight and seed rot in conifers. The sexual stage of R. therryanum has not been found, however, it has been speculated that Herpotrichia juniperi, which causes brown felt blight, is the sexual stage of R. therryanum. In this study, we conducted phylogenetic analysis using 28S large subunit (LSU) rDNA, 18S small subunit (SSU) rDNA, translation elongation factor 1-alpha (tef1), and RNA polymerase II second largest subunit (rpb2). Four isolates were identified as R. therryanum based on their morphological characteristics; together with two strains of H. juniperi, they composed a clade supported by high bootstrap and Bayesian posterior probability values. Therefore, we conclude that the snow mold previously described as R. therryanum is phylogenetically H. juniperi.