Trichoderma rugosum Y.B. Zhang & W.Y. Zhuang, 2018

Zhang, Yu-Bo & Zhuang, Wen-Ying, 2018, New species of Trichoderma in the Harzianum, Longibrachiatum and Viride clades, Phytotaxa 379 (2), pp. 131-142 : 138-139

Trichoderma rugosum Y.B. Zhang & W.Y. Zhuang , sp. nov. ( Fig. 3 )

Fungal names: FN 570576

Etymology:— The specific epithet refers to the rugose stromatal surface.

Type: — CHINA. Hubei: Huanggang, Qichun County, alt. 41 m, on a fire-blackened stump of Cinnamomum bodinieri Levl. , 9 Aug 2017, Z. H. Yu 11325 (holotype HMAS 254548, ex-type culture HMAS 247269).

Stromata solitary or aggregated in small numbers, pulvinate, rugose, outline irregular, ca. 1–8 mm in diam., 1 mm high. Surface yellowish brown to reddish brown, becoming dark in 3% KOH. Ostiolar dots black, numerous, densely disposed. In section, cortical tissue of textura intricata, 11–21 μm thick, cells pale orange, thick-walled, 2–4 μm wide (n = 30); subcortical tissue of textura intricata, cells hyaline or slightly orange, thin-walled, 2–4.5 μm wide; subperithecial tissue of textura epidermoidea, cells hyaline, thick-walled, 7–29 × 5–15 μm; tissue at the base of textura intricata, hyphae hyaline to light orange, thin-walled, 2.2–6 μm wide. Perithecia subglobose or flask-shaped, 157.5– 217 × 106–171 μm; peridium hyaline, 8–15 μm thick at flanks, 13–20 μm thick at the base. Ostioles 57–79 μm high, 14–42 μm wide at the apex. Asci subcylindrical, 65–83 × 4.3–6 μm. Ascospores hyaline, verruculose, dimorphic, distal cells globose to subglobose, 3–4 × 2–3.5 μm, L / W 1–1.3; proximal cells subglobose to ellipsoid, 2.5–4.5 × 2.5–3.5 μm, L / W 1–1.4.

Colony on CMD 42–54 mm in radius after 72 h at 25 ° C, covering the plate after 4–5 days. Colony outline nearly circular, radial, aerial hyphae short and loosely distributed. Conidiation noted after 2 days on aerial hyphae. Conidiophores trichoderma-like, always re-branching once. Phialides subulate or ampulliform, 5–13 × 2–4 μm, L / W 1.7 –5.8, 1–2 μm wide at the base. Conidia green, warted, often oblong or ellipsoid, less subglobose, 3–4 × 2.2–3 μm, L / W 1 – 1.5 . Yellowish pigment produced ; no distinct odor detected.

Colony on PDA 48–55 mm in radius after 72 h at 25° C, covering the plate after 4–5 days. Colony outline nearly circular, radial, dense, aerial hyphae abundant. Conidiation noted after 2 days on aerial hyphae near the plug. Yellowish pigment produced; no distinct odor detected.

Colony on SNA 27–30 mm in radius after 72 h at 25° C, covering the plate after 6–7 days. Colony outline nearly circular, semitranslucent. Conidiation noted after 4 days in the distal region of the colony, in minute granules and pulvinate pustules. No diffusing pigment produced; no distinct odor detected.

Additional specimen examined:— CHINA. Tibet: Linzhi, Mêdog County, alt. 850 m, on fruiting body of Ganoderma sp. , 21 Sep 2016, K. Chen, Y. B. Zhang, Z. H. Yu, Z. Q. Zeng, X. C. Wang & H.D. Zheng 11139 ( HMAS 254536, culture HMAS 247270).

Notes:— Trichoderma rugosum is diagnostic by the combination of rugose stromata, cortical tissue with interwoven hyphae, warted conidia, and yellow pigment produced in CMD and PDA media. It appears to be a sister to T. thermophilum , which possesses angular cells in cortical tissue, larger perithecia (205–260 × 131–197 μm), yellowish peridium turning orange-brown in KOH, narrower phialides (5–9 × 1.8–2.5 μm) and smooth conidia ( Qin & Zhuang 2016b).

Figures

FIGURE 3. Trichoderma rugosum. a–d Stromata on natural substrate. e Perithecium in section. f Cortical and subcortical tissues in section. g Subperithecial tissue in section. h Stroma base in section. i Ascus. j–l Cultures after 14 days at 25 °C (j CMD, k PDA, l SNA). m–p Conidiophores (CMD, 4 days). q Chlamydospores. r Conidia (CMD, 4 days). Bars: a–d = 1 mm, e = 50 μm, f–h, m–q = 20 μm, j–l = 10 mm, i, r = 10 μm.