Cytospora sinensis L. Lin & X. L. Fan

Li, Jieqiong, Li, Canting, Wang, Ganlin, Zhu, Liangliang & Huang, Lili, 2025, Cytospora longdensis sp. nov. and C. sinensis (Diaporthales, Valsaceae) associated with Populus alba subsp. pyramidalis canker and dieback in China, MycoKeys 118, pp. 345-359 : 345-359

Cytospora sinensis L. Lin & X. L. Fan , Studies in Mycology 109: 381 (2024)

Fig. 3

Description.

Sexual morph: not observed. Asexual morph: Conidiomata immersed in bark, erumpent when mature, discoid, with multiple locules. Conceptacle absent. Ectostromatic disc isabelline or greenish black, circular to ovoid, (285 –) 305–452 (– 512) μm in diameter, with single ostiole per disc. Ostiole black, circular to ovoid, (38 –) 45–84 (– 103) μm in diameter. Locules numerous, divided with shared walls. Conidiophores hyaline, thin-walled, unbranched, or branched at the bases, 12.5–23.2 × 1.2–2.2 μm (av. = 17.6 ± 2.7 × 1.6 ± 0.2 μm, n = 30). Conidiogenous cells enteroblastic, phialidic, subcylindrical to cylindrical. Conidia hyaline, smooth, allantoid, aseptate, 4.5–5.9 × 1.6–2.1 μm (av. = 5.2 ± 0.4 × 1.8 ± 0.1 μm, n = 50).

Culture characteristics.

Colonies at 25 ° C on PDA are initially white, flat, growing up to 6.2 cm in diameter after three days, becoming olivaceous and completely covering the 9.0 cm Petri dish after five days.

Additional materials examined.

China • Ningxia Hui Autonomous Region, Guyuan City, Longde County, Shatang Town , 35°35'12.5"N, 106°7'7.4"E, on cankered and infected branches of Populus alba subsp. pyramidalis , 30 July 2022, J. Q. Li & L. L. Huang ( NWAFU H 180 , culture: D 180; NWAFU H 182 , culture: D 182; NWAFU H 184 , culture: D 184) .

Notes.

Cytospora sinensis has been reported from Populus species in Gansu and Yunnan provinces of China ( Lin et al. 2024). In the present study, three isolates causing canker and dieback on Populus alba subsp. pyramidalis in the Ningxia Hui Autonomous Region were identified as C. sinensis based on the phylogenetic topology (Fig. 1 ) and morphological characteristics consistent with previous descriptions (Fig. 3 , Lin et al. 2024).

Figures

Figure 1. Phylogenetic tree of Cytospora based on maximum likelihood analysis of a combined DNA sequence dataset of ITS, act, rpb 2, tef 1 - α, and tub 2 genes. Bootstrap values ≥ 50 % (maximum likelihood) and posterior probabilities ≥ 0.5 (Bayesian) are presented at the branches. Values lower than these thresholds are marked with “ * ”, and absent are marked with “ - ”. Type materials are marked with “ T ”. Isolates from this study are highlighted in blue. The tree was rooted to Diaporthe vaccinii (CBS 160.32).

Figure 3. Cytospora sinensis (D 184). A View of conidiomata on branch; B, C Transverse section through a conidioma; D, E Longitudinal section through a conidioma; F Conidiophores and conidiogenous cells; G Conidia; H Cultures on PDA after five days, front side (left) and back side (right). Scale bars: 500 μm (A); 100 μm (B, C, E); 50 μm (D); 5 μm (F, G).