Trichoderma acremonioides 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 : 137-138

Trichoderma acremonioides Y.B. Zhang & W.Y. Zhuang , sp. nov. ( Fig. 2 )

Fungal names: FN 570575

Etymology:— The specific epithet refers to the simply branched conidiophores.

Type:— CHINA. Yunnan: Dali, Jizu Mountain, alt. 1840 m, on rotten twigs, 21 Sep 2017, Y.B. Zhang, H.D. Zheng, X.C. Wang & Y. Zhang 11591 (holotype HMAS 254566, ex-type culture HMAS 247271).

Stromata solitary, pulvinate, outline circular or irregular, ca. 1–3 mm diam., 0.5 mm high (n = 15), surface smooth, yellowish brown to reddish brown, becoming dark in 3% KOH. Ostiolar dots dark, always inconspicuous. In section, cortical tissue of textura angularis, 27–50 μm thick, cells pale yellowish brown, thick-walled, 3–6 × 2–3.6 μm (n = 30); subcortical tissue of textura angularis, cells hyaline or slightly yellowish, thin-walled, 3.5–6 × 2–5 μm; subperithecial tissue of textura epidermoidea, cells hyaline, thin-walled, 4–16 × 3.5–11 μm; tissue at the base of textura epidermoidea mixed with textura intricata, cells hyaline to slightly yellow, thin-walled, 5–18 × 3.5–10 μm, hyphae hyaline to slightly yellowish, thin-walled, 2–5 μm wide. Perithecia subglobose or flask-shaped, 187–280 × 94–153 μm; peridium hyaline or light yellow, 9–15 μm thick at flanks, 14–21 μm thick at the base. Ostioles (31–)70–93 μm high, 11–25 μm wide at the apex. Asci subcylindrical, 83–100 × 5–6 μm. Ascospores hyaline, verruculose, dimorphic, distal cells globose to subglobose, 3.8–4.7 × 3.5–4.5 μm, L/W 1–1.2; proximal cells subglobose to ellipsoid, 4.2–6 × 3.2–4.3 μm, L/ W 1.0 –1.5.

Colony on CMD 26–30 mm in radius after 72 h at 25 °C, covering the plate after 7 days. Colony outline circular, semitranslucent, aerial hyphae inconspicuous. Conidiation noted after 3 days on aerial hyphae. Conidiophores acremonium- to verticillium-like. Phialides subulate or ampulliform, 7.5–13 × 1.8–2.8 μm, L/ W 3.5 –7, 1.4–2.3 μm wide at the base. Conidia green, warted, subglobose, oblong or ellipsoid, 3.5–6 × 2.5–3.2 μm, L/ W 1.2 –2. No diffusing pigment produced; no distinct odor detected.

Colony on PDA 19–20 mm in radius after 72 h at 25 °C, covering the plate after 17 days. Colony with lobed margin, aerial hyphae dense. Conidiation noted after 2 days on aerial hyphae near the plug. No diffusing pigment produced; no distinct odor detected.

Colony on SNA 4–6 mm in radius after 72 h at 25 °C, 31–35 mm in radius after 17 days. Colony outline nearly circular, semitranslucent, radial. Conidiation noted after 5 days near the plug. Chlamydospores noted after 10 days, terminal or intercalary, 7–13 × 6–10 μm, L/W 1–1.3. No diffusing pigment produced; no distinct odor detected.

Additional specimens examined: — CHINA. Yunnan: Baoshan, Gaoligong Mountain , alt. 2300 m, on rotten wood, 16 Sep 2017, Y.B. Zhang, H.D. Zheng, X.C. Wang & Y. Zhang 11398 ( HMAS 279611 ) ; Yunnan: Dali, Jizu Mountain , alt. 1835 m, on rotten wood, 21 Sep 2017, Y.B. Zhang, H.D. Zheng, X.C. Wang & Y. Zhang 11581 ( HMAS 254558 ) ; Yunnan: Dali, Jizu Mountain , alt. 1840 m, on rotten wood, 21 Sep 2017, Y.B. Zhang, H.D. Zheng, X.C. Wang & Y. Zhang 11582 ( HMAS 254559 ) ; Yunnan: Dali, Jizu Mountain , alt. 1840 m, on rotten twigs, 21 Sep 2017, Y.B. Zhang, H.D. Zheng, X.C. Wang & Y. Zhang 11583, 11584, 11585, 11586, 11587, 11588 [ HMAS 254560 , 254561 , 254562 (culture HMAS 247272 ), 254563, 254564, 247257] .

Notes:— Trichoderma acremonioides locates in the Viride clade, featured by the acremonium- to verticillium-like conidiophores. It is morphologically similar to T. eijii and T. pezizoides , and phylogenetically associated with them but receiving very low statistical support ( MPBP = 57%). Trichoderma eijii has similar conidiophore branching patterns, but differs in cortical tissues of textura intricata, and smaller ascospores and conidia (3.2–3.8 × 2.8–3.5 μm for distal part-ascospores, 3.8–4.7 × 2.5–3.1 μm for proximal part-ascospores, 2.8–3.5 × 2.4–3.0 μm for conidia) ( Kim et al. 2013). Trichoderma peziziodes forms verticillium-like conidiophores, longer phialides (22–24 μm) and larger conidia (2.8–11.6 × 1.8–4.4 μm) ( Liu & Doi 1995).

Figures

FIGURE 2. Trichoderma acremonioides (HMAS254566). a–d Stromata on natural substrate. e Stroma after rehydration. f Rehydrated stroma in 3% KOH. g Perithecium in section. h Cortical and subcortical tissues in section. i Subperithecial tissue in section. j Stroma base in section. k Ascus. l–n Cultures after 6 days at 25 °C (l CMD, m PDA, n SNA). o–r Conidiophores (CMD, 6 days). s Conidia (SNA, 13 days). Bars: a, b, d = 2 mm, c, e, f = 500 μm, g = 50 μm, h–k, o–r = 20 μm, l–n = 10 mm; s = 10 μm.