Thyronectria berberidis R.Ma & S.N.Li, 2018

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 : 22-23

Thyronectria berberidis R.Ma & S.N.Li , sp. nov. Fig. 2 .

MycoBank # MB 825056

Holotype:— CHINA, Xinjiang Uygur Autonomous Region, Ili , Huocheng County, 61 groups of natural protected forest, 44°27’37.40’’N, 80°21’46.68’’E, alt. 1184 m, on twigs of Berberis heteropoda, R. Ma , 22 July 2017, (XJ-FPL 2177, living ex-type culture, CGMCC3.18998 and CBS 144512 ).

Etymology:— berberidis , named after the host genus, Berberis .

Host/Distribution:—from Berberis heteropoda in northwestern China.

Original description:—Asexual state: Undetermined. Sexual morph: mycelium not visible around the ascomata or on the host. Stromata erumpent through the epidermis, (0.37–)0.5–0.78(–0.95) mm high (n = 40), 0.3–1.7(–4.6) mm in diam., brown to black, becoming purple red in KOH and yellow in LA, pseudoparenchymatous, cells forming textura angularis, intergrading with the ascomatal wall. Ascomata were superficial, aggregated in groups of 3–28, brown dark, becoming purple in KOH and yellow in LA, globose to obovoid, slightly rough, 235–286 μm high, 253–352 μm diam., cupulate upon drying. The ascomatal wall was 38–59 μm thick and composed of two regions: outer region 34–45-μm thick, intergrading with the stroma, cells forming textura globulosa or textura angularis, with pigmented walls about 1.5-μm thick; inner region 17–27μm thick and composed of elongate, thin-walled, hyaline cells, forming textura prismatica. Asci were clavate, increasing in size as the ascospores matured, eight-spored, biseriate above, uniseriate below, (55.5–)55.7–69.3(–73.7) × (9.4–)9.6–11.9(–12.8) μm (n = 15). Ascospores were ellipsoidal to fusiform, slightly curved, (1–6)7-septate, (11.9–)18.6–26.4(–32.4) × (4.3–)6.2–8.4(–9.8) μm (n = 80), hyaline and smooth.

Culture characteristics:—In culture, the colony grew on average 7.3 mm /d on PDA at 25 ° C. On day 4, the mycelium appeared white. After 9 days, concentric circles of a pale-orange pigment were visible in the medium, and by day 15, the mycelia filled the plate.

Other specimens examined:— Xinjiang Uygur Autonomous Region, Ili, Huocheng county , Fushou mountain , 44°25’37.94’’N, 80°47’17.31’’E, alt. 1182 m, on twigs of Berberis heteropoda, R. Ma , 15 August 2017 (XJ-FPL 2433, paratype; living culture, XJAU 2433-3 ) ; Xinjiang Uygur Autonomous Region, Ili, Huocheng county , Fushou mountain , 44°25’35.27’’N, 80°47’21.45’’E, alt. 1197 m, on twigs of Berberis heteropoda, R. Ma , 15 August 2017 (XJ-FPL 2441, paratype; living culture, XJAU 2441-6 ) .

Notes:—The major taxonomic characters of the fungus, such as the well-developed stromata on natural substrates and multiseptate ascospores in asci are strong evidence that this species belongs to the genus Thyronectria . Among the known species of the genus, T. berberidis is closely related to T. aurigera which has clavate asci and transversely septate ascospores not forming ascoconidia. However, T. aurigera differs from T. berberidis in having wider asci [10–20 μm vs. (9.4–)9.6-11.9(–12.8) μm] and smaller ascospores [(14.9–)17–20.8(–24.7) × (4.4–)5.0–6.4(–7.3) μm vs. (11.9–)18.6–26.4(–32.4) × (4.3–)6.2–8.4(–9.8) μm] ( Hirooka et al. 2012). Moreover, the five-locus phylogeny indicates that T. berberidis is a phylogenetically separate taxon.

Figures

FIGURE 2. Thyronectria berberidis. A–B: Perithecia on natural substrata. C: Median section of perithecium in water. D: Median section of perithecium in LA. E: Asci. F–K: Ascospores. L: Colonies on PDA after 4 days (left) and 9 days (right). Scale bars:A = 2 mm; B = 100 μm; C–D = 50 μm; E–K = 10 μm.