Trichoderma zelobreve Jing Z. Sun & X.Z. Liu, 2020

Gu, Xin, Wang, Rui, Sun, Quan, Wu, Bing & Sun, Jing-Zu, 2020, Four new species of Trichoderma in the Harzianum clade from northern China, MycoKeys 73, pp. 109-132 : 109

Trichoderma zelobreve Jing Z. Sun & X.Z. Liu sp. nov. Fig. 5

Etymology.

Greek zelo, meaning emulation + breve , referred to Trichoderma breve .

Type.

China. Chaoyang District, Beijing, 40°0'41"N, 116°23'37"E, ca. 35 m elev., 19 Oct 2018, isolated from soil, Jing Z. Sun (HMAS 248254, holotype), ex-type culture CGMCC 3.19695.

Description.

On CMD after 72 h, colony radius covering the plate at 25 °C and 30 °C, 11-12 mm at 35 °C. Colony hyaline, indistinctly radial; Aerial inconspicuous. No diffusing pigment, not distinct odor (Fig. 5B ). Conidial production noted after 5 days, starting around the original inoculum. Small pustules formed at the colony margin, first white, olivaceous after 6 d, with hairs protruding beyond the surface. Chlamydospores unobserved.

On PDA after 72 h, colony radius 55-58 mm at 25 °C, covering the plate at 30 °C, 8-9 mm at 35 °C. Colony white to yellow-white; mycelium dense and radial. Aerial conspicuous. No diffusing pigment, not distinct odor (Fig. 5A ). Conidial production noted after 3 days, starting around the inoculum, effuse in the aerial hyphae, first white, turning green after 4 d. Chlamydospores unobserved.

On SNA after 72 h, colony radius 62-63 mm at 25 °C, covering the plate at 30 °C, 7-8 mm at 35 °C. Colony hyaline, regularly circular; mycelium loose. Aerial conspicuous. No diffusing pigment, not distinct odor (Fig. 5A ). Conidial production noted after 2 days, starting around the inoculum, effuse in the aerial hyphae. Small pustules formed along with two concentric rings, first white, turning yellow-green after 3 d, with hairs protruding beyond the surface. Conidiophores pyramidal with opposing branches, the distance between branches relatively large (Fig. 5F ). Phialides, sometimes solitary, often paired or in whorls of 2-3 (Fig. 5F ); whorls typically cruciate but often nearly verticillate; rarely conidiophores nodose and phialides disposed in more or less botryose clusters (Fig. 5G, H ). Phialides ampulliform to lageniform, often constricted below the tip to form a narrow neck, hyaline (Fig. 5G, H, I ), (3.5-)4.0-6.0(-7.0) × (2.2-)2.6-3.2(-3.5) µm (x̄ = 4.8 × 2.9 μm, n = 30), length/width ratio (1.1-)1.4-2.1(-2.5) (x̄ = 1.5, n = 30), base 1.4-2.1 μm (x̄ = 1.7 μm). Conidia ovoid to subglobose, smooth, hyaline when young, becoming green to dark green with age, (2.0-)2.3-2.6(-2.9) × (1.5-)1.8-2.2(-2.5) µm (x̄ = 2.4 × 2.0 μm, n = 30), length/width ratio (0.8-)1.1-1.4(-1.7) (x̄ = 1.2, n = 30) (Fig. 5J ). Chlamydospores unobserved.

Additional specimen examined.

China. Chaoyang District, Beijing, 40°0'41"N, 116°23'37"E, ca. 35 m elev., isolated from soil, 19 Oct 2018, Jing Z. Sun, living culture CGMCC 3.19696.

Teleomorph.

Undetermined.

Note. Characterized by tree-like conidiophores, branches paired or in whorls of 3-4, ampulliform to lageniform (4.0-6.0 × 2.6-3.2 μm), ovoid to subglobose conidia (2.2-2.6 × 1.8-2.2 μm). Differs from Trichoderma breve by shorter phialides and smaller conidia, as well as the cultural characteristics and growth rates.

Figures

Figure 5. Trichoderma zelobreve (CGMCC 3.19695). Cultures at 25 ° C after 3 days (A on PDA B on CMD C on SNA) D conidiation pustules on CMD after 10 days E conidiation pustules on SNA after 10 d F conidiophores G, I conidiophores and phialides H phialides with conidia J conidia. Scale bars: 25 µm (F); 10 µm (G-J).