Cytospora tanaitica Norph., Bulgakov & K. D. Hyde

Wang, Caixia, Jiang, Ning, Liu, Chuli, Xu, ZiYan, Lu, Hailong & Ma, Rong, 2025, Morphology and molecular phylogeny reveal new species and records of Diaporthales from Betula in Xinjiang, China, MycoKeys 125, pp. 167-204 : 167-204

Cytospora tanaitica Norph., Bulgakov & K. D. Hyde , Fungal Diversity 75: 172 (2015)

Fig. 9

Description.

Conidiomata pycnidial, serried, semi-immersed in the bark, conical, 1200–2000 μm diam., 400–650 μm high, with multiple subdivided locules with common walls. Conceptacle absent. Ectostromatic disc honey, circular to ovoid, 350–650 μm diam., with a single ostiole per disc in the centre. Ostiole grey to black, 75–140 μm diam. Conidiophores borne along the locules, hyaline, branched, (13 –) 15–28.5 (– 32) × 1.5–2 μm. Conidiogenous cells enteroblastic, phialidic, subcylindrical to cylindrical. Conidia hyaline, allantoid, thin-walled, eguttulate, aseptate, smooth, (5 –) 5.5–6 (– 7) × 1.5–2 (av. = 5.8 ± 0.4 × 1.7 ± 0.1, n = 50) μm, L / W ratio = 3.2–3.8.

Culture characteristics.

Colonies on PDA flat, spreading, with abundant aerial mycelium and rough margin, grey to dark green, reaching 90 mm diam. after 2 weeks at 25 ° C, sterile.

Materials examined.

China • Xinjiang Uygur Autonomous Region, Altay Prefecture, Altay City, Alahake Town, Haxionggou , from branches of Betula pendula , 7 October 2024, Rong Ma, Caixia Wang & Hailong Lu ( XJAU 4047 , cultures CFCC 71675 , CFCC 71676 ) ; • Xinjiang Uygur Autonomous Region, Altay Prefecture, Altay City , from branches of Betula pendula , 7 October 2024, Rong Ma, Caixia Wang & Hailong Lu ( XJAU 4064 , cultures CFCC 71677 and CFCC 71678 ) ; • Xinjiang Uygur Autonomous Region, Altay Prefecture, Qinghe County, Xileasheke Village , from branches of Betula pendula , 8 October 2024, Rong Ma, Caixia Wang & Hailong Lu ( XJAU 4084 , cultures CFCC 71683 , CFCC 71684 , CFCC 71685 ) .

Notes.

Cytospora tanaitica was first described from Betula pubescens var. glabrata in Russia ( Ariyawansa et al. 2015). In the present study, seven isolates obtained from Betula pendula in Xinjiang, China, clustered within a single clade together with the ex-type strain of Cy. tanaitica in the phylogenetic tree (Fig. 2 ). However, the conidia of our specimens were larger than those of the holotype (5.5–6 × 1.5–2 μm vs. 3.5–4 × 0.6–0.7 μm) ( Ariyawansa et al. 2015). Based on the molecular phylogenetic evidence and the shared host genus, the isolates obtained in this study are identified as Cy. tanaitica , representing a new host and geographic record for this species.

Figures

Figure 2. Maximum Likelihood tree of Cytospora ribis species complex generated from combined ITS, act, rpb 2, tef 1 and tub 2 sequence data. Bootstrap support values ≥ 50 % and Bayesian posterior probabilities ≥ 0.90 are demonstrated at the branches. Ex-type strains are marked in bold.

Figure 9. Morphology of Cytospora tanaitica from Betula pendula. A, B. Habit of conidiomata on branch; C, D. Transverse section through conidiomata; E. Longitudinal section through conidiomata; F. Conidiophores and conidiogenous cells; G. Conidia. Scale bars: 500 μm (B – E); 10 μm (F – G).