Cytospora populina (Pers.) Rabenh., Deutschl. Krypt.-Fl. (Leipzig) 1: 148. 1844

Li, Jiangrong, Li, Jieting & Jiang, Ning, 2024, Morphology and phylogeny of Cytospora (Cytosporaceae, Diaporthales) species associated with plant cankers in Tibet, China, MycoKeys 104, pp. 51-70 : 51

Cytospora populina (Pers.) Rabenh., Deutschl. Krypt.-Fl. (Leipzig) 1: 148. 1844

Fig. 3

Description.

Associated with branch canker disease of Prunus cerasifera . Sexual morph: Stromata immersed in bark. Ascostromata, erumpent through the surface of bark, lenticular, extending to a large circular area, (750-)900-1200(-1350) μm diam. Disc grey to black, circular to ovoid, (85-)100-150(-195) μm in diameter. Ostioles numerous, dark brown to black, at the same level as the disc, (25-)31-46(-52) μm diam. Locules dark brown, arranged circularly, flask-shaped to spherical, (180-)195-285(-340) μm diam. Asci clavate to elongate obovoid, (45-)55.5-62.5(-67) × (6.5-)8-12(-16) μm, 4-spored. Ascospores biseriate, elongate-allantoid, thin-walled, hyaline, aseptate, (15-)18.5-23.5(-25.5) × (4-)4.5-5.5(-6.5) μm (x̄ = 20.4 × 5.1 μm). Asexual morph: Undetermined.

Culture characteristics.

Colonies on PDA flat, with flocculent aerial mycelium and entire edge, initially white, becoming luteous and reaching 80 mm diameter after 10 days at 25 °C, sterile.

Materials examined.

China, Tibet Tibetan Autonomous Region, Shigatse City, Sangzhuzi District , Gongjuelinka Park , on cankered branches of Prunus cerasifera , 2 August 2022, Jin Peng, Jiang Ning and Liu Min (XZ063); culture CFCC 58856 .

Notes.

Cytospora populina has been reported from Populus canadensis in Argentina, Salix psammophila in Shaanxi Province of China and Acer pubescens Rubus sp. in Uzbekistan ( Farr 1973; Fan et al. 2015; Gafforov 2017). This fungus is distinguished from the other Cytospora species by its 4-ascospored asci and undiscovered asexual state ( Fan et al. 2015). In the present study, we firstly found this fungus causing cankered branches of Prunus cerasifera in Tibet, China.

Figures

Figure 3. Cytospora populina (CAF 800085) A, B canker disease symptom C ascostromata D transverse section through an ascostroma E asci and Ascospores F ascospores. Scale bars: 2000 µm (B); 500 µm (C); 200 µm (D); = 10 µm (E-F).