Chionobium takahashii, gen. et sp. nov., associated with snow blight of conifers in Japan

ABSTRACT

Gremmenia abietis (Dearn.) Crous (syn: Phacidium abietis) was originally described in North America to accommodate the species associated with snow blight of Abies and Pseudotsuga spp. In Japan, this species was first observed on the dead needles on Abies sachalinensis and Picea jezoensis var. jezoensis in 1969. However, the identity of Japanese species was unclear due to the lack of molecular data and the absence of anamorph description. In this study, we collected fresh specimens from various conifer species (A. sachalinensis, A. veitchii, Pic. jezoensis var. jezoensis, Pic. jezoensis var. hondoensis, Pinus koraiensis, and Pin. pumila) in Japan and revised the taxonomy based on morphological and phylogenetic analyses. Phylogenetic analyses based on nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS), nuc 28S rDNA (28S), and RNA polymerase II second largest subunit (RPB2) regions indicated that the species belongs to Phacidiaceae. Conidiomata formed in vitro produced pyriform, hyaline conidia without mucoid appendage, which distinguished the species from phylogenetically related genera. Consequently, we established Chionobium takahashii to accommodate the snow blight fungus in Japan. Further phylogenetic analyses also indicated that C. takahashii includes several distinct clades corresponding to the host genera (Abies, Picea, Pinus). Morphological differences among those clades were unclear, suggesting that C. takahashii may contain host-specific cryptic species.

KEYWORDS:

• Cryptic species
• Phacidiaceae
• Phacidiales
• 2 new taxa

ACKNOWLEDGMENTS

We thank Dr. J. B. Tanney for valuable discussions and comments. We express our gratitude to Canadian National Mycological Herbarium (DAOM) and University of Helsinki (H) and their curators for the loan of specimens, the staff of the University of Tokyo Hokkaido Forest for sampling and the loan of specimens, and Mr. Tetsuo Mutsuji for allowing us to take samples.

DISCLOSURE STATEMENT

No potential conflict of interest was reported by the author(s).

SUPPLEMENTARY MATERIAL

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00275514.2024.2302283

Additional information

Funding

This study was financially supported by Japan Society for the Promotion of Science (JSPS) KAKENHI grant [no. 22J11197], Japan Science and Technology Agency (JST) SPRING grant [no. JPMJSP2108], and the Institute for Fermentation, Osaka, Japan.