Pestalotiopsis changjiangensis N. Jiang, in Jiang, Voglmayr, Xue, Piao & Li, Microbiology Spectrum: 10.1128/spectrum.03272-22, 10 (2022)

Index Fungorum number: IF 841309; MycoBank number: MB 841309; Facesoffungi number: FoF 11692;

Etymology – named after the collection site of the type specimen, Changjiang Li Autonomous County.

Pathogenic to host leaves. Asexual state: Conidiomata in culture sporodochial, aggregated or solitary, erumpent, pulvinate, dark brown, 300–850 μm diam., exuding black conidial masses. Conidiophores indistinct, usually reduced to conidiogenous cells. Conidiogenous cells hyaline, smooth, cylindrical to sphaerical, annelidic, 3.5–6 × 2–5.5 μm, mean ± SD = 4.7 ± 1.1 × 3.4 ± 1 μm. Conidia fusoid, straight, 4-septate, smooth, not to slightly constricted at the septa, (19–)20–22.5(–24) × 7–8(–8.5) μm, mean ± SD = 21.2 ± 1.4 × 7.7 ± 0.4 μm (n = 50), L/W = 2.4–3.3; basal cell obconic with a truncate base, thin-walled, hyaline or pale brown, (2–)3–4 μm; median cells 3, trapezoid or subcylindrical, pale brown to brown, thick-walled, the first median cell from base 4.5–5.5 μm long, the second cell (4.5–)5–5.5 μm long, the third cell (4–)4.5–6 μm long, together (13.5–)14.5–16(–16.5) μm long; apical cell conic with an acute apex, thin-walled, hyaline or pale brown, (2–)2.5–4(–5) μm long; basal appendage indistinct or absent; apical appendage indistinct, tubular, bent, 1.5–4.5(–7) μm long, mean ± SD = 3 ± 1.1 μm. Sexual morph unknown.

Culture characters – Colonies on MEA flat, spreading, with flocculent aerial mycelium and undulate edge, pale luteous, reaching a 70-mm diameter after 10 days at 25°C, sterile; on PDA, flat, spreading, with flocculent aerial mycelium forming concentric rings and undulate edge, white, reaching a 65-mm diameter after 10 days at 25°C, forming black conidiomata with black conidial masses.

Material examined – China, Hainan Province, Changjiang Li Autonomous County, Bawangling National Forest Park, on diseased leaves of Castanopsis tonkinensis (Fagaceae), 16 November 2018, Yong Li (holotype CAF 800024 = JNH0020; ex-holotype culture CFCC 54314); ibid., on diseased leaves of Castanopsis hainanensis, 14 November 2018, Yong Li (CFCC 54433); ibid., on diseased leaves of Cyclobalanopsis austrocochinchinensis, 16 November 2018, Yong Li (CFCC 52803).

Distribution – China

Sequence data – ITS: OK339739 (ITS1/ITS4); tef1: OK358500 (EF1-728F/EF2); tub2: OK358515 (Bt2a/Bt2b)

Notes – Three isolates of Pestalotiopsis collected from Castanopsis hainanensis, C. tonkinensis, and Cyclobalanopsis austrocochinchinensis clustered into a distinct and well-supported clade, which is newly described as P. changjiangensis here (Fig. 1). Its conidia are characterized by the lack of a basal appendage and an indistinct apical appendage, which is unique within the genus Pestalotiopsis.

Fig. 9. Morphology of Pestalotiopsis changjiangensis (CFCC 54314). A. Colony on PDA after 10 d at 25 °C; B. Colony on MEA after 10 d at 25 °C; C. Conidioma formed on PDA; D. conidiogenous cells; E–G. conidia. — Scale bars: C = 300 μm; D–G = 10 μm.