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

Fig. 12

Etymology.

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

Diagnosis.

Masuyamyces xishanensis 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. 2022, Dan Xie ( holotype HMAS 354188 , dried culture prepared from NFF 1608 ; ex-holotype culture CGMCC 3.28599 = NFF 1608 ) .

Description.

Sexual morph not observed. Asexual morphs observed both synnematous and mononematous. Synnematous morph: pesotum-like, the base transparent or light brown, (112 –) 158–296 (– 345) μm tall, including the conidiogenous apparatus, (35 –) 87–117 (– 172) μm wide. Conidiogenous cells hyaline, (5 –) 9–18 (– 22) × 1–1.5 μm. Conidia hyaline, one-celled, cylindrical, (2 –) 2.5–4 (– 5) × (1 –) 1.5–2 (– 2) μm. Mononematous morph: hyalorhinocladiella-like, conidiogenous cells arising directly from mycelium, (5 –) 7–39 (– 61) × (0.5 –) 1–1.5 (– 2) µm; conidia hyaline, single-celled, smooth, obovoid to oblong, (2 –) 2.5–3.5 (– 4) × (0.5 –) 1–1.5 (– 2) 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, the colonies margin smooth, part of the mycelium grows in the agar, pure white. Optimal growth temperature 30 ° C, no growth observed at 5 ° C, slow growth at 10 ° C.

Ecology.

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

Distribution.

Currently known only from Shandong Province, China.

Additional specimens examined.

China • Shandong Province: Yantai City , from H. ligniperda , Apr. 2022, D. Xie (living culture NFF 1609 ) .

Notes.

Masuymyces xishanensis is phylogenetically most closely related to M. dongshanensis . Morphologically, M. xishanensis differs from M. dongshanensis by the absence of ascomatal necks, a more conspicuous pesotum-like stage, and a darker basal pigmentation. Based on both phylogenetic and morphological evidence, we propose the recognition of M. xishanensis 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 12. Morphological characteristics of Masuyamyces xishanensis sp. nov. (NFF 1608). a. Fifteen-day-old culture on 2 % MEA; b, c. Pesotum-like asexual morph; d. Pesotum-like asexual morph: conidiogenous cells and conidia; e – g. Hyalorhinocladiella-like asexual morph: conidiogenous cells and conidia. Scale bars: 200 μm (b, c); 20 μm (d – g).