Cytospora lhaluensis Ning Jiang & B. Cao, in Cao et al., Fungal Diversity 132: 473 (2025)

Index Fungorum number: IF 571958; MycoBank number: MB 571958; Facesoffungi number: FoF 17097; Figs. 1, 2

Etymology – refers to Lhalu Wetland National Nature Reserve, the locality of the type specimen.

Holotype – CAF800091.

Conidiomata Pycnidial, ostiolated, semi-immersed in the host bark, scattered, pulvinate, with multiple locules. Conceptacle absent. Ectostromatic disc brown, circular to ovoid, (120–)150–220(–320) µm diam., with one ostiole per disc. Ostioles dark, at the same level as the disc, (25–)40–70(–90) µm diam. Locule numerous, arranged circularly or elliptically with independent walls, 120–200 µm diam. Peridium comprising few layers of cells of textura angularis, brown to dark brown. Conidiophores hyaline, unbranched, thin walled, filamentous. Conidiogenous cells enteroblastic polyphialidic, 7–12.47–17.5 × 1.5–2.21–3 µm (n = 20). Conidia hyaline, allantoid, smooth, aseptate, thin walled, 5.5–6.5–7.5 × 1.5–2.16–2.5 µm (n = 20). Colonies on PDA flat, spreading, with flocculent mycelium and entire edge, initially white, becoming brown after 10 days, reaching a 90 mm diameter after 25 days at 25 °C in the dark.

Material examined – CHINA, Xizang Autonomous Region, Lhasa City, Lhalu Wetland National Nature Reserve, on dead branches of Prunus davidiana, 28 Jul 2022, Peng Jin, Yuanyuan Liu, Ning Jiang, Min Liu, JN22.149 (CAF800091, holotype; CFCC 58880, ex-type), JN22.150 (living culture CFCC 58886) and JN22.151 (living culture CFCC 58887).

GenBank – CFCC 58880: PP965509 (ITS), PP957867 (act), PP957874 (rpb2), PP957881 (tef1), PP957888 (tub2); CFCC 58886: PP965510 (ITS), PP957868 (act), PP957875 (rpb2), PP957882 (tef1), PP957889 (tub2); CFCC 58887: PP965511 (ITS), PP957869 (act), PP957876 (rpb2), PP957883 (tef1), PP957890 (tub2).

Notes – Cytospora lhaluensis from Prunus davidiana in the present study is phylogenetically close to C. berberidis from Berberis dasystachya (Fig. 1). These two species share similar conidial shape and size, but differs in the locule number in the conidiomata (Liu et al. 2015a).

Figure 1 – Maximum likelihood (GTR + G + I) tree illustrating the phylogenetic placement of the Cytospora species discussed in-text (in bold) within the genus. This phylogenetic tree is based on the alignment of concatenated ITS, act and rpb2 sequences. Branches are labelled with bootstrap prob abilities = 70% across 1,000 bootstrapping replicates, and type specimens are denoted by a superscript “T”. Diaporthe vaccinii CBS 160.32 was used as an outgroup.

Figure 2 – Cytospora lhaluensis from Prunus davidiana (CAF800091, holotype). a Symptoms of canker disease on the host. b, c, e Conidiomata formed on branches. d Longitudinal section through the conidioma. f Transverse section through the conidioma. g Conidiophores and conidiogenous cells. h Conidia. Scale bars: d–f = 200 µm, g, h = 10 µm.