Trichoderma vermifimicola 2020

Trichoderma vermifimicola Jing Z. Sun & X.Z. Liu, sp. nov.2020

MycoBank No: 833234

Holotype China. Yongning, Yinchuan, the Ningxia Hui Autonomous Region, 40°0'41"N, 116°23'37"E, ca. 1678 m elev., from the substrates for earthworm cultivation, 18 Oct 2018, Jing Z. Sun (HMAS 248255, holotype), ex-type culture CGMCC 3.19694.

Morphological description

 On CMD after 72 h, colony radius 49–51 mm at 25 °C, 51–52 mm at 30 °C, 4–5 mm at 35 °C. Colony hyaline, irregularly circular, indistinctly zonate; mycelium loose. Aerial hyphae short, inconspicuous. No diffusing pigment, not distinct odor. Conidial production noted after 3 days, starting around the inoculum (Fig. 3B). Small pustules formed at the colony margin, first white, turning blue-green after 7 d, with hairs protruding beyond the surface. Chlamydospores unobserved.

On PDA after 72 h, colony radius 55–58 mm at 25 °C, 55–56 mm at 30 °C, 5–6 mm at 35 °C. Colony white-green to bright green, regularly circular, distinctly zonate; mycelium dense and radial. Aerial hyphae short, inconspicuous. No diffusing pigment, not distinct odor. Conidial production noted after 2 days, starting around the inoculum, effuse in the aerial hyphae, first white, turning green after 2 d (Fig. 3A). Chlamydospores unobserved.

On SNA after 72 h, colony radius 48–50 mm at 25 °C, 51–52 mm at 30 °C, 3–4 mm at 35 °C. Colony hyaline, regularly circular, distinctly zonate; mycelium loose, especially at the margin. Aerial hyphae short, inconspicuous. No diffusing pigment, not distinct odor. 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 (Fig. 3C). Conidiophores pyramidal with opposing branches, the distance between branches relatively large, each branch terminating in a whorl of 2–3 phialides, phialides sometimes solitary on the main axis (Fig. 3F, H, K); whorls typically cruciate, but often nearly verticillate (Fig. 3K); rarely conidiophores nodose and phialides disposed in more or less botryose clusters (Fig. 3H). Phialides ampulliform to lageniform, often constricted below the tip to form a narrow neck, hyaline, (4.4–)5.0–10.5(–11.2) × (2.0–)2.5–3.0(–3.5) µm (‒x = 6.6 × 2.7 µm, n = 30), length/width ratio (1.5–)1.8–2.8(–5.3) (‒x = 2.4, n = 30), base 1.6–2.5 µm ‒(x = 1.9 µm) (Fig. 3G, I, K). Conidia ovoid to subglobose, smooth, hyaline when young, becoming green to dark green with age, (2.0–)2.3–2.6(–3.0) × (1.5–)2.0–2.4(–2.8) µm (‒x = 2.4 × 2.2 µm, n = 50), length/width ratio (1.0– )1.1–1.4(–1.7) (‒x = 1.2, n = 50) (Fig. 3J). Chlamydospores unobserved. No odor; no diffusing pigment observed.

Habitat: the substrates for earthworm cultivation

Distribution: China. 

GenBank Accession: ITS MN594472、MN594473   RPB2 MN605870、MN605871 TEF1-a MN605881、MN605882

Notes: Characterized by tree-like conidiophores, verticillate or in whorls of 3–4, ampulliform to lageniform phialides (5.0–10.5 × 2.5–3.0 µm), ovoid to subglobose conidia (2.4–2.6 × 2.0–2.5 µm). Differs from Trichoderma simmonsii by forming loose branches in whorls, relatively longer and thinner phialides, smaller conidia, and the fewer pustules on SNA.

Reference: Gu X, Wang R, Sun Q, Wu B, Sun J-Z (2020) Four new species of Trichoderma in the Harzianum clade from northern China. MycoKeys 73: 109–132. https://doi.org/10.3897/mycokeys.73.51424

Figure 3. Trichoderma vermifimicola (CGMCC 3.19694). 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, H conidiophores G, J, K conidiophores and phialides I conidia. Scale bars: 25 µm (F, H); 10 µm (G, J–K).