Trichoderma liaoningense G. S. Jin & Z. X. Zhu sp. nov.

Fig. 7

Etymology.

Named after Liaoning Province, China, where the species was collected.

Diagnosis.

Rapidly growing on PDA, forming dense colonies with abundant pale green to dark green pustules; phialides ampulliform; conidia obovate to subglobose.

Typification.

China • Liaoning Province, Shenyang city, Shenbei road, 41°55'30"N, 123°37'20"E, 1261 m alt., on twig, 20 Sep. 2024, Z. X. Zhu, G. S. Jin, J. Ji, G. L. Zhao, X. Z. Li 1914 (Holotype HMJAU 34752, ex-type culture CGMCC 7.671).

Sexual morph.

— Unknown.

Cultures and asexual morph.

On PDA at 25 ° C, colony radius 57–60 mm after 72 h, with the plate fully covered after 4–5 days. Colonies white, with conspicuous aerial hyphae. Conidiation appearing after 72 h; pustules abundant, white when young, becoming dark green with age, fully covering the plate after 10 days. Conidiophores trichoderma-like, divergent in whorls of 2–4 phialides or with solitary phialides along the main axis. Phialides lageniform, (8.5 –) 9.5–13.2 (– 18.3) × (2.5 –) 2.8–3.7 (– 4.1) μm (n = 20), l / w (2.6 –) 2.9–4.3 (– 5.6), 1.7–2.6 (– 2.8) μm wide at the base (n = 20). Conidia hyaline when young, becoming green during growth, obovate, (3.4 –) 3.6–4.4 (– 4.9) × (2.5 –) 2.6–3 (– 3.2) μm (n = 20), l / w 1.2–1.5 (– 1.8). Odor absent; no pigment observed.

On CMD at 25 ° C, colony radius 68–70 mm after 72 h, with the plate fully covered after 4 days. Colonies white, with inconspicuous aerial hyphae. Conidiation appearing after 4 days; pustules abundant, white to dark green, irregularly disposed in a broad concentric ring. Odor absent; no pigment observed.

On SNA at 25 ° C, colony radius 40–43 mm after 72 h, with the plate fully covered after 7 days. Colonies white, with rare aerial hyphae. Conidiation appearing after 6–7 days; pustules zonate, spreading at the colony margin and near the center. Odor absent; no pigment observed.

Notes.

Trichoderma liaoningense is morphologically similar to T. alni, as both species are characterized by dense, thick mycelium on PDA with pale green conidiation and by green conidiation developing at the distal margin of the colony on CMD (Jaklitsch 2009). As in other members of the Brevicompactum clade, such as T. brevicompactum and T. protrudens, T. liaoningense forms pustules around the colony margin and in discrete patches on SNA and CMD. However, T. liaoningense exhibits a faster growth rate (57–60 mm on PDA and 68–70 mm on SNA) than T. brevicompactum (30–50 mm on PDA, ca. 35 mm on SNA) and T. protrudens (30–38 mm on PDA and 30–41 mm on SNA). In addition, T. liaoningense shares obovate conidia with T. protrudens (Degenkolb et al. 2008). Detailed morphological comparisons are provided in Table 4.

Phylogenetically, T. liaoningense forms a distinct lineage within the Brevicompactum clade and differs from T. protrudens (DIS 119 F) by 34 nucleotide substitutions in the 848 bp rpb 2 locus, corresponding to an overall sequence similarity of approximately 96 %.