Stylonectria qilianshanensis2020

Stylonectria qilianshanensis Z.Q. Zeng & W.Y. Zhuang, sp. nov.

2020

Fungal Names: FN 570729

Holotype: China. Gansu Province, Wuwei, Chashugou, on decayed fruitbodies of an ascomycete on bark of Picea asperata, 26 August 2018, Z.Q. Zeng, X.C. Wang & H.D. 

Zheng 12155 (HMAS 255803).

Morphological description

Perithecia gregarious, up to 30 in a group, parasitic on decayed fruitbodies of an ascomycete, deep red to dark red, turning black red in 3% KOH and light yellow in 100% LA, subglobose to globose, not becoming cupulate upon drying, (216–)255–344 × (186–)206–304 μm (n = 12), apex broadly discoid, flattened, 50–70 μm high, 160–220 μm in diameter, slightly constricted below, with a tiny papilla. Perithecial wall of two layers, 25–38 μm thick, outer layer 20–31 μm, of textura angularis, cells 5–8 × 2–4 μm, walls 0.8–1.0 μm thick; inner layer 5–7 μm, of textura prismatica, cells 8–12.5 × 3–5 μm, walls 0.5–0.8 μm thick. Asci clavate, with an apical ring, 8-spored, 55–88 × 5–8(–10) μm. Ascospores ellipsoidal, ends rounded, 1-septate, light brown, smooth, uniseriate, 10–13 × 5–5.5 μm. Asexual state unknown.

Habitat: on decayed fruitbodies of an ascomycete on bark of Picea asperata Distribution: China 

GenBank Accession:ACL1 MT087289; ITS MT084413; RPB2 MT087288

Notes: Stylonectria qilianshanensis is morphologically similar to S. wegeliniana in having the perithecia with a broad, discoid apex, clavate asci with an apical ring, and ellipsoidal ascospores with rounded ends (Petch 1938). However, S. qilianshanensis differs in having smaller asci [55–88 × 5–8(–10) μm vs 90–100 × 9–10 μm] and ascospores (10–13 × 5–5.5 μm vs 10–18 × 6–9 μm) (Petch 1938). Sequence comparisons indicate that ITS of S. qilianshanensis differs from that of S. wegeliniana by 20 bp in a total length of 576 bp; ACL1 and RPB2 of the former differ from those of the latter by 84 bp and 38 bp, respectively among 722 bp and of 869 bp in length. The asexual state of the fungus remains unknown until culture is available.

Reference: Zeng Z-Q, Zheng H-D, Wang X-C et al. (2020) Ascomycetes from the Qilian Mountains, China

Stylonectria qilianshanensis a–c ascomata on natural substrate d–f median section through perithecium g–l ascus with ascospores m–q ascospores. From HMAS 255803. Scale bars: 1 mm (a–c); 50 μm (d–f); 10 μm (g–q).