Trichoderma beijingense K. Chen & W.Y. Zhuang, 2017

Chen, Kai & Zhuang, Wen-Ying, 2017, Seven soil-inhabiting new species of the genus Trichoderma in the Viride clade, Phytotaxa 312 (1), pp. 28-46 : 33-36

Trichoderma beijingense K. Chen & W.Y. Zhuang , sp. nov. Fig 3

Fungal Names: FN570276.

Etymology: The specific epithet refers to the type locality.

Diagnosis. Colony fast-growing on CMD, PDA and SNA at 25 °C. Conidiophores trichoderma-like, phialides narrowly lageniform, conidia green, subglobose, less commonly globose.

On CMD after 72 h colony radius 50–51 mm and mycelium covering the plate after 4 d at 25 °C. Colony hyaline, radial, margin well defined, aerial hyphae common, absent at the colony center. Conidiation noted after 3 d, first formed on aerial hyphae, conidial pustules noted after 5 d, spreading abundant around the periphery of the colony, hemispherical, loose, 1–2 mm diam, white, turning green after 8 d. Chlamydospores common. No distinct odor, no diffusing pigment observed.

On PDA after 72 h colony radius 48–50 mm and mycelium covering the plate after 4 d at 25 °C. Colony hyaline, zonate, aerial hyphae abundant. Conidiation noted after 3 d, effuse in aerial hyphae or in densely disposed shrubs, shrubs appearing in 3–4 concentric zones. Conidiophores symmetrical, trichoderma-like. Phialides typically solitary or paired, sometimes in whorls of 3, narrowly lageniform, rarely subulate, 8.9–12.4(–15.2) × 2.1–3.1 μm, l/ w 3.2 –5.7, 1.4–2.2 μm wide at the base (n = 40). Conidia green, subglobose, less commonly globose, 3.3–4.2 × 2.8–3.3 μm, l/w (1.0–)1.1–1.5 (n=40). Chlamydospores common. No distinct odor, no diffusing pigment observed.

On SNA after 72 h colony radius 20–21 mm and mycelium covering the plate after 9 d at 25 °C. Colony hyaline, margin slightly lobed and ill-defined, aerial hyphae inconspicuous. Conidiation noted after 3 d, formed in pustules, pustules spreading around the original inoculum, pulvinate, flat, adhered firmly to surface, up to 8 mm in diam, green with white margin. Chlamydospores common. No distinct odor, no diffusing pigment observed.

Strains examined: CHINA. Beijing: Yanqing, Yudushan, elev. 926 m, isolated from soil, 8 July 2015, K. Chen TC727 (holotype HMAS 248804, ex-type culture CGMCC 3.18322). ibid., K. Chen TC728 (HMAS 248805).

Notes: Trichoderma beijingense is characterized by its flat, pulvinate pustules on SNA, which is uncommon in Trichoderma . The species appears to be a separate terminal branch in the phylogenetic tree, and was grouped with T. atroviride , T. paratroviride and T. subviride , which is poorly supported ( Fig 1 , MPBP/MLBP/BIPP = 67%/74%/–). The above fungi show morphological distinctions, and cannot be confused. In comparison, T. atroviride has shorter phialides [(4–)6–10(–12) μm], and grows faster on SNA at 25 °C; T. paratroviride differs in having globose conidia; and T. subviride can be easily distinguished by its much shorter phialides ( Jaklitsch 2011; Jaklitsch & Voglmayr 2015; Qin & Zhuang 2016b).

Figures

FIGURE 1. One of the most parsimonious trees based on the analysis of the combined RPB2 and TEF1 matrix, showing phylogenetic positions of the new species. From left to right: MPBP above 50%, MLBP above 70%, and BIPP above 90% are provided at the nodes.

FIGURE 3. Trichoderma beijingense (HMAS 248804).A–C. Cultures after 7 d at 25 °C (A. CMD; B. PDA; C. SNA); D–E. Conidiation pustules (D. CMD, 7 d; E. SNA, 7 d); F–L. Conidiophores and phialides (PDA, 4 d); M. Chlamydospores (SNA, 14 d); N–P. Conidia (PDA, 4 d). Scale bars:A–C = 20 mm; D–E = 200 μm; F = 20 μm; G–K = 10 μm; L–P = 5 μm.