Trichoderma orarium, Wei, Yu-Hui, Liou, Guey-Yuh, Tzean, Shean-Shong & Hsieh, Sung-Yuan, 2023

Wei, Yu-Hui, Liou, Guey-Yuh, Tzean, Shean-Shong & Hsieh, Sung-Yuan, 2023, Trichoderma orarium (Hypocreales): a new species from Taiwan, Phytotaxa 626 (1), pp. 67-72 : 68

Trichoderma orarium Y.-H. Wei, S.-S. Tzean & G.-Y. Liou, sp. nov. ( Figure 2 )

Mycobank MB849743

Gene sequences:— (ITS) OR510626; (rpb2) OR513045; (tef1) OR513046

Etymology:— orarium is Latin for “coastal,” referring to coastal Northeastern Taiwan where the species was collected.

Diagnosis:— Phylogenetically, T. orarium is closely related both to T. rugulosum and T. hortense . T. orarium differs from T. rugulosum in producing slender phialides and obovate conidia as well as exhibiting a faster growth rate on SNA. T. orarium differs from T. hortense by its obvious yellow diffusing pigment production on PDA at 25 ℃. The latter produces phialides with a sharply restricted neck and obpyriform conidia.

Type:— TAIWAN. Yilan County: Toucheng Township , isolated from coastal soil, Apr 2018, C.-C. Chen & G.-Y. Liou , Type BCRC 18 F0041, stored in a metabolically inactive state (deep-freezing) in the Bioresource Collection and Research Center of the Food Industry Research & Development Institute, Hsinchu, Taiwan .

Description:— On PDA after 72 h, colony radius 17–20 mm at 20 ℃, 39–42 mm at 25 ℃, and 40–43 mm at 30 ℃. After 7 days at 25 ℃, colony radial, zonate, mycelium dense, and floccose in texture; no distinct odor detected; obvious pastel yellow to orange yellow pigment.

On SNA after 72 h, colony radius 24–27 mm at 20 ℃, 55–60 mm at 25 ℃, and 67–69 mm at 30 ℃. After 7 days at 25 ℃, colony hyaline, radial, mycelium sparse, obscurely zonate. Conidiation starting after 2 days, then growing to pustules, firstly white and turning deep green to dark green, obvious at the margin or side wall of the plate. Pustules forming in 3–4 inconspicuous concentric rings. No diffusing pigment. No distinct odor. Conidiophores straight or slightly curved, trichoderma -like, branched at the distinct main axis, mostly paired, occasionally unilateral, sometimes substituted by a solitary phialide or verticillated phialides. Phialides ampulliform to lageniform, straight or slightly curved, typically formed in whorls of 3–5, occasionally paired or solitary, (5.3–)6.7–11.8(–17.1) × 2.1–3.1 µm, l/w ratio (1.7–)2.4–4.9(–7.1), 1.4–2.4 µm wide at the base. Conidia smooth, thin-walled, green, globose, subglobose, or obovate, occasionally elongated oval, 2.2–3.7(–4.6) × 2.0–2.7 µm, l/w ratio 1.0–1.4(–1.6). Chlamydospores not observed.

Figures

FIGURE 2. Trichoderma orarium BCRC 18F0041. A–C. Colonies after 7 d at 25 ˚C; A. from above on PDA, B. from below on PDA, C. from above on SNA. D–L. Conidiophores, phialides, and conidia formed on SNA. M–N. Conidia. Scale bar = 10 µm. Photographs by Y.-H. Wei.