Graphilbum jiuguanense 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-

Graphilbum jiuguanense D. Xie, H. W. Chen & D. F. Chi sp. nov.

Fig. 10

Etymology.

The epithet jiuguanense (Latin) refers to the Jiu Guan village from where this taxon was first isolated.

Diagnosis.

Graphilbum jiuguanense is phylogenetically distinct from all morphologically similar species, from which it can be readily distinguished using molecular sequence data for the ITS, the elongation factor 1 - alpha ( TEF 1 - α) and the calmodulin ( CAL) regions (Suppl. materials 6 – 8).

Type.

China • Shandong Province: Yantai City , from H. ligniperda , Nov. 2022, Dan Xie ( holotype HMAS 354190 , dried culture prepared from NFF 1626 ; ex-holotype culture CGMCC 3.28602 = NFF 1626 ) .

Description.

Sexual morph not observed. Asexual morphs observed both synnematous and mononematous. Synnematous morph: pesotum-like, (109 –) 179–309 (– 358) μm long including conidiogenous apparatus, curving, the base dark yellow, (32 –) 42–80 (– 141) μm in width. Conidiogenous cells hyaline, (14 –) 18–44 (– 53) × (1 –) 2–2.5 (– 3) μm. Conidia hyaline, one-celled, cylindrical to obovoid, (3 –) 4–5.5 (– 6) × (1 –) 1.5–2 (– 3) μm. Mononematous morph: hyalorhinocladiella-like, conidiogenous cells arising directly from mycelium, (9 –) 24–57 (– 92) × (0.5 –) 1–1.5 (– 2) µm; conidia hyaline, single-celled, smooth, ellipsoidal to ovoid, (2.5 –) 3–5 (– 6) × (1 –) 1.5–2 (– 2.5) μm.

Culture characteristics.

Colonies on 2 % MEA medium fast growing in the dark, hyphae submerged in agar with aerial mycelium, mycelial growing disorderly, white. The optimal temperature for growth is 30 ° C, reaching 86 mm diam in 7 days. Growth slower at 35 ° C, 7 mm diam in 7 days.

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 , Nov. 2022, D. Xie (living culture NFF 1627 ) .

Notes.

Phylogenetic analyses show that Gr. jiuguanense is phylogenetically close to Gr. niveum . Morphologically, the colony of Gr. niveum is light brown, while that of Gr. jiuguanense is white with a disorganized mycelial growth pattern. Furthermore, Gr. jiuguanense produces both pesotum-like and hyalorhinocladiella-like asexual morphs, whereas Gr. niveum exclusively exhibits the hyalorhinocladiella-like morph ( Chang et al. 2021). Based on both phylogenetic and morphological evidence, we propose the recognition of Gr. jiuguanense as a novel species.

Figures

Figure 10. Morphological characteristics of Graphilbum jiuguanense sp. nov. (NFF 1626). a. Ten-day-old culture on 2 % MEA; b, c. Pesotum-like asexual morph; d – g. Hyalorhinocladiella-like asexual morph: conidiogenous cells and conidia. Scale bars: 100 μm (b); 10 μm (c – e); 20 μm (f, g).