Pestalotiopsis shaanxiensis N. Jiang, in Jiang, Voglmayr, Xue, Piao & Li, Microbiology Spectrum: 10.1128/spectrum.03272-22, 20 (2022)

Index Fungorum number:IF 843390; MycoBank number: MB 843390; Facesoffungi number: FoF 11699;

Etymology – named after the collection site of the type specimen, Shaanxi Province.

Pathogenic to host leaves. Asexual state: Conidiomata in culture sporodochial, aggregated or solitary, erumpent, pulvinate, black, 100–550 μm diam., exuding black conidial masses. Conidiophores indistinct, usually reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth, cylindrical to spherical, annelidic, 7–15 × 2–5.5 μm, mean ± SD = 10.5 ± 3 × 4.3 ± 1.1 μm. Conidia fusoid, straight or slightly curved, 4-septate, smooth, slightly constricted at the septa, (21–)22–24.5(–25) × (7–)7.5–8.5(–9) μm, mean ± SD = 23.1 ± 1.3 × 8 ± 0.4 μm (n = 50), L/W = 2.5–3.3; basal cell obconic with a truncate base, thin-walled, hyaline or pale brown, (3.5–)4–5(–5.5) μm; median cells 3, trapezoid or subcylindrical, concolourous, pale brown to brown, thick-walled, the first median cell from base (4–)4.5–5.5(–6) μm long, the second cell (4.5–)5–5.5(–6) μm long, the third cell (4.5–)5–5.5(–6) μm long, together (13.5–)14.5–16.5(–17.5) μm long; apical cell conic with an acute apex, thin-walled, hyaline or pale brown, (3–)3.5–4.5(–5) μm long; basal appendage single, unbranched, tubular, centric, straight or slightly bent, (1.5–)2.5–6(–7.5) μm long, mean ± SD = 4.2 ± 1.6 μm; apical appendages 3, unbranched, tubular, centric, straight or slightly bent, (13–)13.5–18(–22) μm long, mean ± SD = 15.6 ± 2.3 μm. Sexual morph unknown.

Culture characters – Colonies on MEA flat, spreading, with flocculent aerial mycelium forming concentric rings and undulate edge, white to pale luteous, reaching a 40-mm diameter after 10 days at 25°C, forming black conidiomata with black conidial masses; on PDA, flat, spreading, with flocculent aerial mycelium forming concentric rings and entire edge, white, reaching a 70-mm diameter after 10 days at 25°C, forming black conidiomata with black conidial masses.

Material examined – China, Shaanxi Province, Hanzhong City, Foping County, Dongshan Mountain, on diseased leaves of Quercus variabilis, 7 September 2019, Yong Li (holotype CAF 800047; ex-holotype culture CFCC 54958); ibid., CFCC 57356.

Distribution – China

Sequence data – ITS: ON007026 (ITS1/ITS4); tef1: ON005043 (EF1-728F/EF2); tub2: ON005054 (Bt2a/Bt2b)

Notes – Two isolates of Pestalotiopsis shaanxiensis from Quercus variabilis formed a distinct clade phylogenetically close to P. biciliata and P. camelliae-oleiferae (Fig. 1). Morphologically, P. shaanxiensis has obviously wider conidia than P. camelliae-oleiferae (7 to 9 μm in P. shaanxiensis versus 5 to 7 μm in P. camelliae-oleiferae) (28). P. shaanxiensis can be distinguished from P. biciliata by one versus two basal appendages in the latter (16).

Fig. 20. Morphology of Pestalotiopsis shaanxiensis (CFCC 54958). A. Colony on PDA after 10 d at 25 °C; B. Colony on MEA after 10 d at 25 °C; C. Conidiomata formed on PDA; D, E. conidiogenous cells giving rise to conidia; F, G. conidia. — Scale bars: C = 200 μm; D–G = 10 μm.