Leptographium ligniperdae 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-

Leptographium ligniperdae D. Xie, H. W. Chen & D. F. Chi sp. nov.

Fig. 11

Etymology.

The epithet ligniperdae (Latin) refers to the insect of Hylurgus ligniperda , the bark beetle vector of this species.

Diagnosis.

Leptographium ligniperdae is phylogenetically distinct from all morphologically similar species, from which it can be readily distinguished using molecular sequence data for the beta-tubulin ( βT), the elongation factor 1 - alpha ( TEF 1 - α), and the calmodulin regions ( CAL) (Suppl. materials 9 – 11).

Type.

China • Shandong Province: Yantai City , from H. ligniperda infesting Pinus thunbergii , Apr. 2022, Dan Xie ( holotype HMAS 354189 , dried culture prepared from NFF 1605 ; ex-holotype culture CGMCC 3.28598 = NFF 1605 ) .

Description.

Sexual morph not observed. Asexual morphs observed both synnematous and mononematous. Synnematous morph: pesotum-like, (110 –) 200–310 (– 356) μm long including conidiogenous apparatus, the base dark brown, expanding branches at the apex, (22 –) 28–58 (– 78) μm in width. Conidiogenous cells hyaline, cylindrical, (7 –) 9–16 (– 19) × 1–2.5 μm. Conidia hyaline, one-celled, cylindrical to obovoid, (5 –) 6.5–8 (– 10) × (2.5 –) 3–3.5 (– 4) μm. Mononematous morph: leptographium-like, arising directly from mycelium; conidiophores, simple to strongly branched, hyaline, (41 –) 43–127 (– 226) µm long; conidiogenous cells (6 –) 8–18 (– 26) μm long; conidia hyaline, single-celled, smooth, oblong, (3.4 –) 4.8–7.6 (– 9.4) × (1.3 –) 1.7–2.5 (– 3) μm.

Culture characteristics.

Colonies on 2 % MEA medium fast growing in the dark, reaching 88 mm in diam. in 7 days at 25 ° C, growth rate up to 15 mm / day at the fastest. Hyphae submerged in agar with aerial mycelium, dark-olivaceous to brown. Optimal growth temperature 25–30 ° C, no growth observed at 5 ° C and 35 ° C.

Ecology.

Isolated from beetles found on Pinus hosts. Host trees: Pinus thunbergii and Pinus densiflora . Insect vector: H. ligniperda .

Distribution.

Currently known only from Shandong Province, China.

Additional specimens examined.

China • Shandong Province: Yantai City , from H. ligniperda infesting Pinus densiflora , Apr. 2022, D. Xie (living culture NFF 1606 ) .

Notes.

Leptographium ligniperda belongs to the L. olivaceum species complex and is most closely related to L. hizoidum and L. sagmatosporum in phylogenetic analyses. Distinguishing between these closely related species based on morphology alone is challenging due to their considerable morphological similarities in conidial size and shape, conidiogenous apparatus structure, and recorded asexual morphs ( Yin et al. 2019).

Figures

Figure 11. Morphological characteristics of Leptographium ligniperdae sp. nov. (NFF 1605). a. Ten-day-old culture on 2 % MEA; b, c. Pesotum-like asexual morph; d – f. Leptographium - like asexual morph: conidiogenous cells and conidia. Scale bars: 200 μm (b); 20 μm (c – f).