Thyronectria berberidicola R. Ma & S.N.Li, 2020

Ma, Rong, Li, Sheng-Nan, Zhao, Ying, Wang, Min, Michailides, Themis J. & Tian, Cheng-Ming, 2020, New species of Nectria and Thyronectria from Xinjiang, China, Phytotaxa 433 (4), pp. 253-264 : 259-260

Thyronectria berberidicola R. Ma & S.N.Li , sp. nov. Fig. 3 .

MycoBank no: MB 830452

Holotype:— CHINA, Xinjiang UygurAutonomous Region, Ili , Huocheng County, Kuerdening in Mohe , 43°12’01.05’’N, 82°47’17.70’’E, elev. 1402 m, on twigs of Berberis heteropoda, R. Ma , 4 August 2016, (XJ-FPL 1366, living ex-type culture).

Etymology:— berberidicola , named after Berberis heteropoda , the known host for this species.

Host/Distribution:—Twigs of Berberis heteropoda in northwestern China.

Original description:—Saprophytic on twigs of Berberis heteropoda . Sexual morph: Mycelium not visible around the ascomata or on the host. Stromata erumpent through the epidermis, 0.6 mm high, 1.7 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, aggregated in groups of 4–22, black brown or bay, subglobose to globose, 265–326 μm high, 228–352 μm in diam., rarely becoming cupulate when dry, becoming slightly purple in KOH and yellow in LA, sometimes the surface scurfy or scaly, yellowish green. Ascomatal wall 33–55 μm thick, composed of two regions: outer region 23–36 μm thick, intergrading with the stroma, cells forming textura globulosa or textura angularis, with pigmented walls about 1.5 μm thick; inner region 15–20 μm thick and composed of elongate, thin-walled, hyaline cells, forming textura prismatica. Asci clavate, increasing in size as the ascospores matured, 8- spored, (8.9–)11.9–20.6(–25.9) × (57.2–)66.9–99.0(–117.9) μm (mean=16.3 × 83 μm, n=80). Ascospores ellipsoidal to fusiform, hyaline, constricted at septa, with 5–8 transverse septa, 1(–2) longitudinal septum, (3.4–)4.5–6.3(–9.1) × (14.7–)19.2–26.2(–33.6) μm (mean=5.4 × 22.7 μm, n=80), smooth, budding to produce hyaline, thin-walled, bacillar ascoconidia, (0.9–)1.1–1.4(–1.6) × (2.9–)3.4–4.2(–4.7) μm (mean=1.2 × 3.8 μm, n=80), l/w = 3.0–3.2, that fill asci. Asexual morph: Undetermined.

Culture characteristics:—The mycelium of cultures grown on PDA at 25 °C appeared white at first, developing a pale-orange pigment after 9 days, sometimes with concentric circles.

Specimens examined:— CHINA, Xinjiang Uygur Autonomous Region, Ili, Huocheng county , Apeiying ditch, 44°25’54.94’’N, 80°46’37.37’’E, elev. 1304 m, on twigs of Berberis heteropoda Schrenk, R. Ma , 14 August 2017 (XJ-FPL 2365, paratype; living culture, XJAU 2365-4) ; CHINA, Xinjiang Uygur Autonomous Region, Ili, Huocheng county , Fushou mountain , 44°23’42.21’’N, 80°42’41.95’’E, elev. 1287 m, on twigs of Berberis heteropoda Schrenk, R. Ma , 13 August 2017 (XJ-FPL 2289, paratype; living culture, XJAU 2289-4) .

Notes:—Molecular data indicated that these isolates formed a distinct clade with high support (MP/ML/ BI=100/100/1). Morphologically, this species is characterized by ellipsoidal to fusiform, hyaline ascospores, with 5–8 transverse septa, and 1(–2) longitudinal septum, with ascospores budding in the ascus to produce ascoconidia, which is similar to the morphology of T. lamyi and T. caudata . However, T. berberidicola can be distinguished from T. lamyi and T. caudata by shorter asci [63.7–98.1 μm vs. 108–143 μm ( T. lamyi ) and 104–143 μm ( T. caudata )] ( Hirooka et al. 2012, Jaklitsch & Voglmayr 2014). Moreover, ascomata of T. berberidicola rarely become cupulate when dry, whereas T. lamyi and T. caudata do not become cupulate when dry. The strain XJAU 2365-4 which was previously reported as T. lamyi has been identified as a new species named T. berberidicola in this study ( Li et al. 2018).

Figures

FIGURE 3. Morphology of Thyronectria berberidicola from Berberis heteropoda (XJAU 1366-1). A–C: Perithecia on natural substrata. D: Median section of perithecium. E: Median section of perithecial wall. F–G:Asci. H–I:Ascospores. J:Ascoconidia. K: Colonies on PDA after 30 days. Scale bars:A = 500 μm; B–C = 200 μm; D =50 μm; E–J = 10 μm.