Cytospora sinopopuli Ning Jiang sp. nov.

Fig. 5

Etymology.

Named after the collection country China (sino -) and the host genus, Populus.

Description.

Associated with branch canker disease of Populus szechuanica var. tibetica. Teleomorph: Pseudostromata Group SII (type s 3), immersed in the bark, scattered to serried, conical, 1700–2450 μm diam., 450–800 μm high, with 6–12 perithecia arranged circularly. Conceptacle absent. Ectostromatic disc buff to honey, circular to ovoid, 420–600 μm diam., with 6–12 ostioles arranged circularly per disc. Ostioles brown to black, 85–150 μm diam. Perithecia flask-shaped to spherical, 350–500 μm diam. Asci hyaline, with chitinoid, refractive ring, clavate, (38.5 –) 45–59 (– 60) × (6.5 –) 9–13.5 (– 14.5) μm, 8 - spored. Ascospores multiseriate, allantoid, thin-walled, hyaline, aseptate, (10 –) 13.5–15.5 (– 16.5) × (2 –) 2.5–3 (– 3.5) (av. = 14.6 ± 1.1 × 2.8 ± 0.3, n = 50) μm, L / W ratio = 4.7–5.7. Anamorph: Undetermined.

Culture characteristics.

Colonies on PDA flat, spreading, with abundant aerial mycelium and entire margin, initially white, turning brown after 1 wk, fast growing, reaching 90 mm diam. after 2 wk at 25 ° C, sterile.

Materials examined.

China, • Xizang Autonomous Region (Tibet), Linzhi (Nyingchi) City, Bomi (Bomê) County, 29 ° 44 ' 1 " N, 96 ° 2 ' 41 " E, 3050 m asl, from cankered branches of Populus szechuanica var. tibetica, 22 Oct. 2024, Ning Jiang, Min Liu, Jieting Li & Yi Li (holotype CAF 800151, ex-type cultures CFCC 71370 and CFCC 71955).

Notes.

Cytospora sinopopuli, isolated from Populus szechuanica var. tibetica (Salicaceae) in Xizang, is phylogenetically closely related to C. lauricola from Laurus nobilis (Lauraceae) in Yunnan (Fig. 1). Currently, C. sinopopuli is known only from its teleomorph, while C. lauricola has been described only in its anamorph stage; therefore, direct morphological comparison between the two species is not possible. Nevertheless, C. sinopopuli is clearly distinguished from C. lauricola by molecular data: 1 / 512 bp (0.19 %) in ITS, 8 / 255 bp (3.14 %) in act, 1 / 625 bp (0.16 %) in rpb 2, and 31 / 264 bp (11.74 %) in tef 1 (Lin et al. 2024).