Trichoderma tenue W.T. Qin & W.Y. Zhuang, 2017

Qin, Wen-Tao & Zhuang, Wen-Ying, 2017, Seven new species of Trichoderma (Hypocreales) in the Harzianum and Strictipile clades, Phytotaxa 305 (3), pp. 121-139 : 133

Trichoderma tenue W.T. Qin & W.Y. Zhuang , sp. nov. FIGURE 7

Etymology:— The specific epithet refers to the slender phialides.

MycoBank: MB 816634

Type: — CHINA. HUBEI: Shennongjia, Tianziya, 2000 m, on rotten twigs, 16 Sep 2014, W. T. Qin, Z.Q. Zeng, H.D. Zheng & K. Chen 9709 (holotype HMAS 273785).

Colony radius on CMD 22–27 mm after 72 h, mycelium covering the plate after 8–9 d at 25 C. Colony dense, circular, aerial hyphae abundant, conidiation noted after 24 h, in whitish granules or pustules, eventually becoming light green. Conidiophores trichoderma- to verticillium-like with phialides solitary or in whorls of 2–5 arising from the main axis. Phialides lageniform or subulate, commonly slender, (6.5–)7–14 × 1.4–2 μm, l/w (3.3–)4.5–6(–7), 1.2–1.8 μm wide at the base (n = 50). Conidia light green, globose or subglobose, smooth, 2.5–3.5 × 2.5–2.8 μm, l/ w 1.0 –1.3(–1.4) (n = 50). No chlamydospores observed. No distinct odor, no diffusing pigment observed.

Colony radius on PDA 24–25 mm after 72 h, mycelium covering the plate after 8 d at 25 C. Colony whitish, dense, with thin, diffuse margin, indistinctly and irregularly zonate. Aerial hyphae richly branched, radial towards margin with surface downy, farinose to floccose. No distinct odor; no diffusing pigment observed.

Colony radius on SNA 15–17 mm after 72 h, mycelium covering the plate after 12 d at 25 C. Colony thin, zonate, aerial hyphae numerous, farinose to floccose, conidiation formed after 24 h on them. No distinct odor; no diffusing pigment observed.

Notes:— Trichoderma tenue is associated with T. priciliae and T. rufobrunneum based on the sequence data ( Figure 1 ). Trichoderma priscilae is fast-growing [ CMD 57–62 mm, PDA 40–43 mm, SNA 52–54 mm], and forms pachybasium-like conidiophores ( Jaklitsch & Voglmayr 2015). Trichoderma rufobrunneum is similar to T. tenue in verticillium-like conidiophores, but differs conspicuously by forming compact pulvinate to hemispherical pustules in culture, fast-growth [ CMD 40–50 mm, PDA 31–35 mm, SNA 21–25 mm], shorter phialides [(6–)8–10(–12.5) × 2–3 μm], and larger conidia [(2.5–)3–4(–5.5) × 2.5–3(–4) μm] ( Zhu & Zhuang 2015).

Figures

FIGURE 1. Maximum parsimony phylogram reconstructed from the combined sequences of RPB2 and TEF1-α. MPBP (left) above 50% and BIPP (right) above 90% are indicated at the nodes. New species proposed are indicated in boldface. TreeBASE no. S19229.

FIGURE 7. Trichoderma tenue (HMAS 273785). a–c. Cultures at 25 C (a. CMD, 9 d; b. PDA, 12 d; c. SNA, 12 d). d. Conidiation tufts (PDA, 12 d). e–j. Conidiophores (CMD, 6 d). k. Conidia (CMD, 6 d). Scale bars: a–c = 20 mm; d = 1 mm; e–j = 20 μm; k = 10 μm.