Thyronectria lamyi (Desm.) Seeler, J. Arnold Arbor.

Li, Sheng-Nan, Zhao, Ying, Tian, Cheng-Ming, Michailides, Themis J. & Ma, Rong, 2018, A new species and a new record of Thyronectria (Nectriaceae, Hypocreales) in China, Phytotaxa 376 (1), pp. 17-26 : 23-24

Thyronectria lamyi (Desm.) Seeler, J. Arnold Arbor. 21: 449. 1940. Fig. 3 .

Basionym : Sphaeria lamyi Desm., Ann. Sci. Nat., Bot. , sér. 2, 6: 246, 1836.

= Nectria lamyi (Desm.) De Not., Sfer. Ital. , 1: 13. 1863.

= Pleonectria lamyi (Desm.) Sacc., Mycotheca Ven. No. 688. 1876.

Host/Distribution:—Pathogen on twigs and branches of Berberis heteropoda . Known from Berberis aquifolium , B. candidula , B. gagnepainii , B. vulgaris , B. thunbergii in Austria and B. hispanica in Spain.

Descriptions:—Mycelium not visible around the ascomata or on the host. Stromata erumpent through the epidermis, 0.5 mm high, 0.8 mm diam., black brown, becoming dark red in KOH and yellow in LA pseudoparenchymatous, cells forming textura angularis, intergrading with the ascomatal wall. Ascomata superficial on well-developed stromata, aggregated in groups of 4–9, subglobose to globose, 189–228 μm high, 202–244 μm diam., not cupulate when dry, blackish brown in colour, becoming purple in KOH and yellow in LA, sometimes the surface with green or slightly yellowish scurf or scaly. Asci widely clavate and increasing in size as ascospores mature, 72.1–100.6(–112.8) × (10.3–)14.2–26.7(–30.6) μm (n = 15), eight-spored, ascospores mainly biseriate. Ascospores ellipsoidal to fusiform, hyaline, constricted at septa, with 5 transverse septa, 1(–2) longitudinal septum, (15.4–)23.7–36.7(–45.1) × (5.1–)6.4– 9.0(–10.5) μm (n = 70), smooth, budding to produce hyaline, thin-walled, bacillar ascoconidia, (3.2–)3.9–4.7(–5.7) × (1.0–)1.3–1.8(–2.8) μm, l/w = (1.65–)2.4–2.8(–3) (n = 100), that fill asci. Asexual morph:—Not observed.

Culture characteristics:—In culture, the colony grew on average 8.8 mm /d on PDA at 25 °C; the colour of the colony was slightly orange with concentric round grains after 5 days. Colony growth on MEA 9 mm /d at 25 °C, pale-orange pigment, with white aerial mycelium. Conidiophores developed on aerial mycelium, 10–23.5 μm long, 1.8–2.7 μm wide at base. Conidia ellipsoidal, oblong to cylindrical, hyaline, straight or slightly curved, rounded at both ends, non-septate, smooth, 4.3–6.7 × 1.3–1.9 μm (n=150).

Specimen examined:— CHINA, Xinjiang Uygur Autonomous Region, Ili, Huocheng County, Apeiying ditch, 44°25’54.94’’N, 80°46’37.37’’E, alt. 1304 m, on twigs of Berberis heteropoda, R. Ma , 14 August 2017 (XJ-FPL 2365, XJAU 2365-4).

Notes:— Thyronectria lamyi used to be called Pleonectria lamyi , and has only been recorded on Berberis spp. The fungus was previously known only from Asia ( Pakistan), Europe and North America ( Hirooka et al. 2012; Jaklitsch & Voglmayr 2014). This is the first collection of Thyronectria lamyi in China and is the first report from Berberis heteropoda . Compared with the description of Hirooka et al. (2012), the Chinese collection has slightly smaller asci [72.1–100.6(–112.8) × (10.3–)14.2–26.7(–30.6) μm vs. 70–145 × 10–40 μm], larger ascospores [(15.4–)23.7–36.7(– 45.1) × (5.1–)6.4–9.0(–10.5) μm vs. (14.5–)18.9–26.1(–32.2) × (5–)5.2–8(–10.8) μm], and the colour of ascomata is slightly different (blackish brown vs. bay to scarlet), which are treated as infraspecific variation.

Figures

FIGURE 3. Thyronectria lamyi. A–C: Perithecia on natural substrata. D: Ascus. E: Budding ascospores. F: Ascoconidia. G: Colony on PDA after 5 days at 25 °C. H: Median section of perithecium in water. I: Median section of perithecium in LA. J: Conidiophores and lateral phialidic pegs on MEA. K: Conidia on MEA. Scale bars: A = 200 μm; B–C = 100 μm; D–F, J–K= 10 μm; H–I = 50 μm.