Leptographium sylvestris M.L. Yin, Z.W. de Beer and M.J. Wingf.

Yin, Mingliang, Wingfield, Michael J., Zhou, Xudong, Linnakoski, Riikka & Beer, Z. Wilhelm de, 2019, Taxonomy and phylogeny of the Leptographium olivaceum complex (Ophiostomatales, Ascomycota), including descriptions of six new species from China and Europe, MycoKeys 60, pp. 93-123 : 93

Leptographium sylvestris M.L. Yin, Z.W. de Beer and M.J. Wingf. sp. nov. Fig. 7

Etymology.

The epithet refers to the host species where the holotype was collected.

Type.

POLAND, Chrosnica, from Pinus sylvestris , Jan. 2008, R. Jankowiak, (PREM 60920- holotype, ex-holotype cultures: CBS 136511 = CMW 34140). FINLAND, Jouhteninen, from Picea abies infested with Ips typographus , Aug. 2005, Z.W. de Beer, (PREM 60921- paratype, ex-paratype cultures: CBS 128833 = CMW 23300).

Description.

Sexual state develop on wood on WA in 14-21 days. Perithecia superficial on wood and agar, base brown to black, globose, unornamented, 91-110 μm in diameter, necks dark brown, cylindrical, slightly curved, 200-480 μm long (including ostiolar hyphae), 26-32 μm wide at base, 15-21 μm wide at the tip. Ostiolar hyphae present, pale brown, straight, septate, numerous, divergent, tapering at the tip, up to 190 μm long. Asci not seen. Ascospores one-celled, hyaline, fusiform to orange section shaped in side view, ellipsoidal in face view, globose in end view, (4.0 –)4.5–5.5(– 5.8) × (2.5 –)2.8–3.7(– 3.9) μm including hyaline gelatinous sheath, 0.3-0.6 μm thick. Conidiophores macronematous, synnematous, swollen at the base, occasionally wider at the stipe, brown to light brown, expanding branches at the apex, 260-500 × 14-57 μm including conidiogenous apparatus. Conidiogenous cells discrete, hyaline, cylindrical, 2-3 per branch, percurrent proliferation, (10 –)11–15(– 18) × 1.5-2.5 μm. Conidia hyaline, obovate to clavate, (3.6 –)4.5–4.9(– 5.2) × (1.6 –)1.7–1.9(– 2.1) μm. Cultural characteristics: Colonies on OA, hyaline at first, later becoming dark yellowish in the center, mycelium appressed and immersed, Perithecia and Pesotum -like asexual morph co-occur in culture. Optimal growth temperature is 30 °C, radial growth rate 5.0 ( ± 0.5) mm/d, growth reduced at 10 °C, no growth at 35 °C.

Host trees.

Pinus sylvestris , Picea abies .

Insect vector.

Ips typographus .

Distributions.

Poland, Finland.

Notes.

The Finnish isolate (CMW 23300) was considered by Linnakoski et al. (2012) to be the same undescribed species as the isolates described above as L. conplurium . The addition of a newly obtained isolate from Poland in the present study, confirmed that the two isolates represented a distinct taxon, clearly separated from all other species in the complex. This is the only new species for which ascomata were obtained in culture. Single ascospore isolates of this species produced ascomata in culture, suggesting that the species is homothallic. The common characters of sexual states of species in this complex are having ascomata with sheath and ostiolar hyphae on the top of neck. This species differs from others by its fusiform to orange section shaped ascospores and slightly curved neck.

Figures

Figure 7. Leptographium sylvestris sp. nov. (CMW 34140) a fourteen-days old culture on OA with black background b synnematous asexual state on wood tissue on WA c conidiophore d conidiogenous apparatus e conidiogenous cells f conidia g-h the sexual state on wood tissue on WA i ascoma j ostiolar hyphae k ascomatal base l ascospores. Scale bars: 100 μm (b), 50 μm (c), 25 μm (d), 10 μm (e), 5 μm (f), 100 μm (g), 100 μm (h), 50 μm (i), 25 μm (j), 20 μm (k), 5 μm (l).