Trichoderma viridulum 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 : 134-136

Trichoderma viridulum W.T. Qin & W.Y. Zhuang , sp. nov. FIGURES 8

Etymology:— The specific epithet refers to the pale green colony.

MycoBank: MB 816635

Type: — CHINA. HUBEI: Shennongjia, Huangbaoping, 1750 m, on rotten twigs, 16 Sep 2014, W. T. Qin, K. Chen, Z.Q. Zeng & H.D. Zheng 9767 (holotype HMAS 273865).

On CMD after 72 h 50–52 mm and mycelium covering the plate after 4 d at 25 C. Colony circular, faintly zonate, aerial hyphae abundant and radially disposed. Conidiation noted after 2 d, starting at the margin of the colony, spreading to tufts or pustules, first white, gradually turning green. No distinct odor; no diffusing pigment observed.

On PDA after 72 h 55–57 mm and mycelium covering the plate after 4 d at 25 C. Colony typically zonate, aerial hyphae abundant and densely arranged. Conidiation noted after 2 d, mainly on the concentric rings, light green. No distinct odor; no diffusing pigment observed.

On SNA after 72 h 32–33 mm and mycelium covering the plate after 5 d at 25 C. Colony hyaline, circular, aerial hyphae sparsely disposed. Conidiation noted after 2 d, starting in short minute shrubs, spreading, developing tufts or pustules, first white, turning green gradually. Conidiophores trichoderma-like, phialides solitary or in whorls of 3–4(– 5), emerging from the main axes. Phialides lageniform to subulate, 6–12(–14) × 2.5–3 μm, l/w (2.1–)2.7–4.8(–5.6), 1.2–2.3 μm wide at the base (n = 120). Conidia green, ellipsoidal, smooth, 3–4.5(–5.2) × 2.3–3.2 μm, l/ w 1.0 –1.6 (n = 120). No chlamydospores observed. No distinct odor; no diffusing pigment observed.

Other specimens examined: CHINA. HEILONGJIANG: Wudalianchi, Laoheishan , 450 m, on rotten wood, 22 Aug 2014, W. T. Qin, Z.Q. Zeng & H.D. Zheng 9026, HMAS 273867 ; HENAN, Luoyang, Longyuwan , 1500 m, on rotten wood, 17 Sep 2013, H.D. Zheng, Z.Q. Zeng & Z.X. Zhu 8707b, HMAS 248772 ; HUBEI: Shennongjia, Huangbaoping , 1750 m, on twigs, 16 Sep 2014, Z.Q. Zeng, K. Chen, W. T. Qin & H.D. Zheng 9764, HMAS 273866 ; ibid., W. T. Qin, K. Chen, Z.Q. Zeng & H.D. Zheng 10068, HMAS 248771 .

Notes:— Trichoderma viridulum is closely related to T. cerinum and T. tomentosum ( Figure 1 ). The latter two fungi have pachybasium-like rather than trichoderma-like conidiophores. Trichoderma cerinum produces smaller ampulliform phialides [4.8–8.2 × 2.8–4.8 μm], smaller conidia [2.4–3.5 × 2.0–2.5 μm], obvious undulate sterile hyphal extensions, and grayish orange pigment on PDA, none of which are observed in T. viridulum ( Bissett et al. 2003) . Trichoderma tomentosum is peculiar for the development of green hemisphaerical pustules in culture, and in having smaller phialides [3.5–5 × 2.5–3.5 μm] and conidia [2.5–3.4 × 1.9–2.3 μm] ( Bissett 1991).

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 8. Trichoderma viridulum (HMAS 273865). a−c. Cultures after 7 d at 25 C (a. CMD; b. PDA; c. SNA). d–i. Conidiophores and phialides (SNA, 7 d). j. Conidia (SNA, 7 d). Scale bars: a–c = 20 mm; d, e, i = 20 μm; f–h, j = 10 μm.