Trichoderma paradensissimum C.L. Zhang, 2023

Zhao, Rui, Mao, Li-Juan & Zhang, Chu-Long, 2023, Three new species of Trichoderma (Hypocreales, Hypocreaceae) from soils in China, MycoKeys 97, pp. 21-40 : 21

Trichoderma paradensissimum C.L. Zhang sp. nov.

Fig. 4

Etymology.

The Latin specific epithet " para " means similar, and " paradensissimum " refers to the phylogenetic proximity and morphological similarity to T. densissimum .

Diagnosis.

T. paradensissimum is characterized by the green to yellow and white pustules formed inconspicuously zonate on PDA or MEA at 25 °C of a 12- h photoperiod after 7 d.

Type.

China: Shanxi Province, Jincheng City , 35°26'57.9"N, 112°45'19.0"E, 929 m alt., isolated from soils of wheat rhizosphere, Jun 2015, Y. Jiang T31823 (Holotype CGMCC 3.24125, stored in a metabolically inactive state. Ex-type culture CGMCC 3.24125) .

Description.

Optimum temperature for growth is 30 °C on CMD, PDA and SNA and 25 °C on MEA. Chlamydospores were common on all media.

Colony radius on CMD after 72 h: 40-42 mm at 25 °C, 63-64 mm at 30 °C, 38-40 mm at 35 °C. Colony well-defined, white, aerial myceli loose and radial. White minute pustules were noted after 2 d around the inoculation plug, white at first, turning yellow green after 3-4 d, then dark green after 5-6 d. Around the point of inoculation, conidiation from dark green to pale green, inconspicuously zonate. Distinctive odor absent. The production of pigment was related to light, media and temperature: around the point of inoculation, it was yellowish at 35 °C in the dark.

Colony radius on PDA after 72 h: 59-65 mm at 25 °C, 64-67 mm at 30 °C, 20-24 mm at 35 °C. Colonies similar to that on MEA. Pustules were noted after 4-5 d. After 7 d, the green to yellow and white pustules were formed as inconspicuously zonate. Distinctive odor absent. The production of pigment was related to light and temperature; it was yellowish at 35 °C in the dark.

Colony radius on MEA after 72 h 58-59 mm at 25 °C, 51-53 mm at 30 °C, 34-35 mm at 35 °C. Colonies white and thick, regularly circular and radial, aerial myceli dense. A few white-yellow large pustules formed inconspicuously zonate. Diffusing pigment or distinctive odor absent.

Colony radius on SNA after 72 h 35-37 mm at 25 °C, 43-44 mm at 30 °C, 15-16 mm at 35 °C. Colony pale white; aerial myceli loose. Conidiation was minute pustules, radial and inconspicuously zonate. Around the point of inoculation, the pustules were green, but white far away from the inoculation. Diffusing pigment or distinctive odor absent. Conidiophores pyramidal; the main axis with side branches sometimes at right angles or inclined upward. The main axis and each branch commonly terminating verticillate, whorl of 3 phialides, sometimes solitary. Phialides ampulliform, (5.4-)7.4-11.0(-15.0) × (2.1-)2.7-3.1(-3.3) μm (mean = 9.4 × 2.9 μm), base (1.6-)1.8-2.3(-2.6) μm (mean = 2.0 μm); phialide length/width ratio (2.1-)2.6-3.7(-4.9)(mean = 3.2) (n = 30). Conidia subglobose to globose, green, (2.6-)2.7-3.0(-3.5) × (2.4-)2.5-2.9(-3.2) μm (mean = 2.9 × 2.7 μm), with length/width ratio of 1.0-1.2 (mean = 1.1) (n = 30). Chlamydospores abundant, common single, sometimes terminal and intercalary, globose to subglobose, (4.6-)5.1-6.2(-6.8) × (3.7-)4.6-5.9(-6.7) μm (mean = 5.7 × 5.4 μm); length/width ratio 1.0 × 1.3(mean = 1.1) (n = 30).

Sexual morph.

Unknown.

Substrate.

Soil.

Distribution.

China, Shanxi Province.

Additional material examined.

China: Shanxi Province, Jincheng City , 35°26'58.1"N, 112°45'19.4"E, 929 m alt., isolated from soil of wheat rhizosphere, Jun 2015, Y. Jiang T31824 .

Notes.

Similar species can be distinguished according to the pigment: T. paradensissimum can produce yellowish pigment on PDA and CMD at 35 °C in the dark, whereas T. guizhouense typically at 35 °C reverse forming a dull orange to brown pigment. However, T. densissimum , T. asiaticum , T. simile and T. zelobreve cannot produce diffusing pigment on PDA. Trichoderma pholiotae and T. paradensissimum can both produce yellow pigment on PDA, but T. pholiotae has a slightly fruity odor on both PDA and CMD, while T. paradensissimum does not have a distinctive odor ( Cao et al. 2022).

Figures

Figure 4. Cultures and anamorph of T. paradensissimum strain T 31823 a-d cultures on different media at 25 ° C with a 12 h light and 12 h darkness cycle after 7 d (a on PDA b on MEA c on CMD d on SNA) e culture on PDA at 35 ° C with darkness after 7 d f conidiation pustules on PDA after 7 d g, j-m conidiophores and phialides (g, j on CMD 3 d k-m on SNA 3 d) h conidia i chlamydospores. Scale bars: 10 μm (g-m).