Masuyamyces dongshanensis D. Xie, H. W. Chen & D. F. Chi, 2025

Xie, Dan, Chen, Huanwen, Jia, Niya, Niu, Fang, Wang, Xiaomei, Yu, Jia & Chi, Defu, 2025, Ophiostomatoid fungi associated with Hylurgus ligniperda, including six new species from eastern China, IMA Fungus 16, pp. e 169382-e 169382 : e169382-

Masuyamyces dongshanensis D. Xie, H. W. Chen & D. F. Chi sp. nov.

Fig. 13

Etymology.

The epithet dongshanensis (Latin) refers to the Dong Shan village from where this taxon was first isolated.

Diagnosis.

Masuyamyces dongshanensis is phylogenetically distinct from all morphologically similar species, from which it can be readily distinguished using molecular sequence data for the ITS and the beta-tubulin ( βT) (Fig. 7 , Suppl. material 12).

Type.

China • Shandong Province: Yantai City , from H. ligniperda , Apr. 2023, D. an Xie ( holotype HMAS 354191 , dried culture prepared from NFF 1645 ; ex-holotype culture CGMCC 3.28603 = NFF 1645 ) .

Description.

Sexual morph perithecial. Perithecia appeared after 35 days of cultivation on sterilized wooden chips or 30 days of cultivation on 2 % MEA, superficial or partly embedded, globose, black, the outer layer with hyphal ornamentation, (249 –) 367–606 (– 727) μm diam. Ascomatal necks black, straight or slightly curved, (410 –) 480–1038 (– 1849) µm long, (77 –) 107–161 (– 195) µm wide at base, (18 –) 22–41 (– 52) µm wide at the apex. In culture, necks sometimes 2–4 per ascoma. Asci and ascospores were not observed. Asexual morphs observed both synnematous and mononematous. Synnematous morph: pesotum-like, the base transparent or light yellow, aggregating into a transparent mucilaginous spore drop, (64 –) 96–218 (– 316) μm tall, including the conidiogenous apparatus, (40 –) 58–108 (– 149) μm wide. Mononematous morph: hyalorhinocladiella-like, conidiogenous cells arising directly from mycelium, (22 –) 23–165 (– 359) × (2 –) 2.5–3.5 (– 4) µm; conidia hyaline, single-celled, smooth, obovoid to bacilliform, (6 –) 7–9 (– 10) × (2 –) 2.5–3 (– 4) μm.

Culture characteristics.

Colonies on 2 % MEA medium slow growing in the dark, reaching 72 mm in diam. in 15 days at 25 ° C, growth rate up to 4.5 mm / day at the fastest, part of the mycelium grows in the agar, pure white. Optimal growth temperature 30 ° C, slow growth at 5–10 ° C.

Ecology.

Isolated from migratory beetles living in Pinus hosts. Insect vector: H. ligniperda .

Additional specimens examined.

China • Shandong Province: Yantai City , from H. ligniperda , Apr. 2023, D. Xie (living culture NFF 1646 ) .

Distribution.

Currently known only from Shandong Province, China.

Notes.

Masuymyces dongshanensis is phylogenetically most closely related to M. xishanensis . Morphologically, it can be distinguished from M. xishanensis by the presence of ascomatal necks and its distinctive pesotum-like asexual morph, which is transparent, mucilaginous, and aggregates into irregularly edged, chip-like masses. Based on both phylogenetic and morphological evidence, we propose the recognition of M. dongshanensis as a novel species.

Figures

Figure 7. Maximum Likelihood tree of Masuyamyces and Ophiostoma ips complex generated from the ITS sequence data. Sequences generated in this study are printed in bold. Bold branches indicate posterior probability values ≥ 0.9, while ML SH-aLRT / UFBooT values of ≥ 75 % are recorded at nodes, < 75 % are indicated by the symbol *. T = ex-type cultures.

Figure 13. Morphological characteristics of Masuyamyces dongshanensis sp. nov. (NFF 1645). a. Fifteen-day-old culture on 2 % MEA; b, c. Perithecium; d, e. Pesotum-like asexual morph; f – h. Hyalorhinocladiella-like asexual morph: conidiogenous cells and conidia. Scale bars: 200 μm (b, c); 100 μm (d, e); 30 μm (f); 20 μm (g, h).