Nigrograna thymi Mapook, Camporesi & K. D. Hyde

Du, Hong-Zhi, Lu, Yu-Hang, Cheewangkoon, Ratchadawan & Liu, Jian-Kui, 2024, Morpho-phylogenetic evidence reveals novel species and new records of Nigrograna (Nigrogranaceae) associated with medicinal plants in Southwestern China, MycoKeys 110, pp. 1-33 : 1-33

Nigrograna thymi Mapook, Camporesi & K. D. Hyde , Fungal Diversity, 87: 68–70 (2017)

Fig. 7

Description.

Saprobic on dead branches of Huangtcia renifolia ( Fabaceae ). Sexual morph: Ascomata 292–359 μm wide, 166–278 μm high (x ̅ = 327 × 218 μm, n = 20), solitary or scattered, immersed or semi-immersed to slightly erumpent through host tissue, coriaceous, globose to subglobose, brown to dark brown, hairs of ascomata 2–3 μm wide, brown, septate, branched. Ostiole inconspicuous, without papillate. Peridium 15–44 μm (x ̅ = 29.5 μm, n = 20) wide, 5–6 layers, comprising dark brown cells of textura angularis. Hamathecium comprising 1–3 μm (x ̅ = 2 μm, n = 20) wide, cylindrical to filiform, septate, branched, smooth-walled pseudoparaphyses. Asci 43–86 × 7–9 μm (x ̅ = 66 × 8 μm, n = 30), 8 - spored, bitunicate, cylindrical to broadly filiform, with small ocular chamber. Ascospores 11–15 × 4–6 μm (x ̅ = 13 × 4.5 μm, n = 50), 1–2 - seriate, overlapping, broadly fusiform to inequilateral, widest at the middle cell, guttulate, smooth-walled, aseptate or 1 - septate, hyaline when immature, becoming 3 - septate, slightly constricted at the septum, pale brown to brown at maturity, without appendages. Asexual morph: Undetermined.

Culture characteristics.

Ascospores germinated on PDA within 24 h, and germ tubes produced from basal cell. Colonies growing on PDA reached 20 mm in diameter after three weeks at 25 ° C in dark. Colonies from above, white in the whole colony and raised in the center, circular, edge entire, margin well-defined; in reverse, grayish-green in the center, white to pale green ring at the margin, no pigmentation on PDA.

Material examined.

China • Yunnan Province, Xishuangbanna Dai Autonomous Prefecture, Mengla County, Xishuangbanna Tropical Botanical Garden Chinese Academy of Sciences . 21°55'50′′N, 101°15'29′′E, elevation 515 m, on dead branches of medicinal plant Huangtcia renifolia (L.) H. Ohashi & K. Ohashi ( Fabaceae ), 10 November 2022, H. Z. Du, D 02 ( HUEST 23.0210 ), living culture UESTCC 23.0210 ; • ibid., Sichuan Province, Leshan City , Emeishan County, 29°36'10"N, 103°21'54"E, elevation 1,100 m, on dead branches of Camellia sinensis (L.) O. Ktze . ( Theaceae ), 18 July 2023, Y. H. Lu & X. D. Liang, EM 03 ( HUEST 23.0194 ), living culture UESTCC 23.0194 .

Notes.

Nigrograna thymi was introduced by Hyde et al. (2017) from Thymus oenipontanus in Italy. Our collections are identical to N. thymi based on morphology and phylogeny (Fig. 1 ). We reported it as new host records from medicinal plants Huangtcia renifolia and Camellia sinensis in China.

Figures

Figure 1. Phylogenetic tree constructed from maximum likelihood (RAxML) analyses of a combined ITS, LSU, rpb 2, SSU, and tef 1 - α sequence data for selected genera within the family Nigrogranaceae (Pleosporales, Dothideomycetes). Branches support for Maximum likelihood (MLBS) equal to or greater than 75 % and Bayesian inference posterior probabilities (BIPP) equal to or greater than 0.95 are marked above or below nodes as MLBS / BIPP. The abbreviation T indicates the ex-type strain. Species names and culture collections in red are newly collected taxa and synonymized isolates. The tree was rooted with Occultibambusa pustula (MFLUCC 11-0502) and O. bambusae (MFLUCC 13-0855).

Figure 7. Nigrograna thymi (HUEST 23.0210, new host record) a host Huangtcia renifolia b branch of Huangtcia renifolia c – f appearance of ascomata on host surface g vertical section through ascoma h hairs on ascomata i peridium j hamathecium k – o asci p germinated ascospore q, r colony on PDA, above (q) and below (r) s – x ascospores. Scale bars: 100 µm (g); 20 µm (h, i, l – p); 10 µm (j, k, s – x).