A new genus Neobelonopsis and two new species of Trichobelonium (Helotiales, Ascomycota) discovered mainly from poaceous grasses native to Asia in Japan.

Mollisioid fungi, represented by Mollisia (Fr.) P. Karst., are characterized by soft, sessile apothecia with globose, dark-celled excipula, hyaline ascospores, and worldwide distribution in temperate regions. Their generic and species delimitation is difficult due to the lack of distinct features, and studies based on DNA sequences are urgently required. Two genera of mollisioid fungi, Belonopsis and Trichobelonium, comprise relatively few species and are recognized by (0-)1-3-septate ascospores, medullary excipulum composed of loosely interwoven hyphae, and calcium oxalate crystals in the excipulum. Specimens of undescribed species that are morphologically assignable to Belonopsis or Trichobelonium were collected from various sites in Japan and their assignment to the proper genera was attempted. According to a molecular phylogenetic analysis involving members of Mollisiaceae based on concatenated sequences of ITS, LSU, and RPB1, eight taxonomic entities were placed in a strongly supported single clade with Mollisiadiesbachiana, separated from the type species of Belonopsis, B.excelsior. A new genus Neobelonopsis was thus proposed to accommodate the undescribed species. In this study, eight new species of Neobelonopsis and two new species of Trichobelonium were described. A new combination was also proposed for M.diesbachiana. The generic distinction of Neobelonopsis and Trichobelonium was supported by molecular analysis. Some additional characteristics to delimit Trichobelonium were identified, such as the presence of anchoring hyphae between the base of the apothecium and subiculum, and the production of abundant crystals and soluble pigments on the colonies. Derivative species of Neobelonopsis were found to have multi-septa in ascospores.

De Novo Genome Assembly of Stinkhorn Mushroom Clathrus columnatus (Basidiomycota, Fungi) Using Illumina and Nanopore Sequencing Data.

We report the reference genome of Clathrus columnatus isolate MO-923, which was isolated from Chichijima Island, the Ogasawara (Bonin) Islands, Japan. Oxford Nanopore Technologies MinION and Illumina sequence reads were assembled using NECAT and polished using Pilon to yield a 36.51-Mb genome with 10,625 predicted protein-coding genes.

Pyrenopeziza orientalipetiolaris sp. nov. in Japan and morphological and genetic comparison with its relevant species P. petiolaris in Europe.

Some Asian fungi are morphologically very similar to European species but belong to different species. A fungus that resembles Pyrenopeziza petiolaris, which commonly occurs on the petioles of Acer pseudoplatanus in Europe, was found on the petioles of Acer spp. and other tree leaves in Japan. The apothecia of this fungus were smaller than those of P. petiolaris, suggesting that it is a different species. To examine this possibility, specimens of this fungus were collected from various hosts in Japan. A detailed morphological examination elucidated that this fungus differed from P. petiolaris in smaller apothecia, marginal cells of the ectal excipulum, and conidia. The ITS sequence difference between this fungus and P. petiolaris was 3.3-4.3%, and they formed distinct clades in the phylogenetic analysis, supporting that they are different species. Consequently, a new species, P. orientalipetiolaris is described. Since an undescribed phialophora-state was observed in the cultures of P. petiolaris for the first time, the morphology under culture is also reported in detail.

Lifecycle of Pyrenopeziza protrusa (Helotiales, Dermateaceae sensu lato) in Magnolia obovata revealed by field observation and molecular quantification.

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.