Trichoderma macrofasciculatum G.Z. Zhang, 2022

Zhang, Guang-Zhi, Yang, He-Tong, Zhang, Xin-Jian, Zhou, Fang-Yuan, Wu, Xiao-Qing, Xie, Xue-Ying, Zhao, Xiao-Yan & Zhou, Hong-Zi, 2022, Five new species of Trichoderma from moist soils in China, MycoKeys 87, pp. 133-157 : 133

Trichoderma macrofasciculatum G.Z. Zhang sp. nov.

Fig. 4

Etymology.

The specific epithet " Trichoderma macrofasciculatum " refers to the morphological feature of the conidiation, conidiophores aggregated into large fascicles in concentric rings.

Typification.

China, Sichuan, Nine-Village Valley, 2405 m (altitude), isolated from soil, 24 September 2016, G.Z. Zhang (Holotype WT 37805).

Diagnosis.

Phylogenetically, Trichoderma macrofasciculatum WT37805 and WT37810 formed a distinct clade and is related to T. polysporum C.P.K. 3131 in the Polysporum clade, but the similarities of rpb2 and tef1 -α between these two species were only 96.41% and 92.81%, respectively. Trichoderma macrofasciculatum cannot grow at 35 °C as T. polysporum and the former formed large and white pustules in concentric rings at 25 °C, elongations were rarely observed and conidia had few guttules, which are distinct from T. polysporum .

Teleomorph.

Unknown.

Growth optimum at 20 °C, slow or limited at 30 °C, absent at 35 °C. Colony radius after 72 h at 25 °C 21-24 mm on PDA, 23-27 mm on CMD, 17-20 mm on MEA and 12-16 mm on SNA. Aerial mycelia abundant on PDA and MEA after incubation for 72 h at 25 °C under a 12 h photoperiod. Conidiation typically in pustules in concentric rings on PDA, solitary or aggregated, producing a Protocrea farinose to granular mat. Diameter of pustules up to 2.2 mm, pompon-like, white. Diffusing pigment and distinct odour absent. Conidiation on MEA typically in pustules in concentric rings, pompon-like as on PDA. On CMD, aerial mycelia sparsely developed. Conidiation aggregated in sporadic pustules near the colony margin, white. On SNA, aerial mycelia few and conidiation not observed. Conidiophores and branches irregularly branched in a dendriform structure, with each branch terminating in a cruciate whorl of up to five phialides. Hyphal septa clearly visible. Phialides flask-shaped, often curved, (4.9-)5.6-7.8(-8.8) × (2.8-)3.0-3.2(-3.4) μm (mean = 6.7 × 3.1 μm), 1.8-2.6 μm (mean = 2.2 μm) near the base; phialide length/width ratio (1.5-)1.8-2.4(-2.8) (mean = 2.1). Conidia subglobose to ellipsoid, hyaline, smooth, with one or few distinctly verrucose, (2.6-)2.8-3.3(-3.6) × (2.4-)2.5-2.7(-2.9) μm (mean = 3.0 × 2.6 μm), length/width ratio 1.0-1.3 (mean = 1.2). Chlamydospores not observed.

Distribution.

China, Sichuan Province.

Additional material examined.

China, Sichuan, Nine-Village Valley , 2405 m (altitude), isolated from soil, 24 September 2016, G.Z. Zhang (WT 37810) .

Notes.

Phylogenetically Trichoderma macrofasciculatum WT 37805 is related to T. polysporum C.P.K. 3131 in the Polysporum clade (Fig. 1 ), but the similarities of rpb2 and tef1 -α between these two species were only 96.41% and 92.81% respectively, with 94 and 41 bp differences amongst 1311 and 1152 bp. Trichoderma macrofasciculatum cannot grow at 35 °C as T. polysporum and the former formed large and white pustules in concentric rings at 25 °C, elongations were rarely observed and conidia had few guttules, which are distinct from T. polysporum ( Lu et al. 2004).

Figures

Figure 1. Phylogenetic tree, based on the Maximum Likelihood analysis of the rpb 2 (left; InL = - 5930.92) and tef 1 - α (right; InL = - 7681.95) dataset. Bootstrap values of Maximum Likelihood (left) and Maximum Parsimony (right) above 50 % are indicated at the nodes. The tree is rooted with Protocrea illinoensis TFC 9698 and P. farinose CPK 3144. New species proposed here are indicated in bold. The type strains are indicated with an asterisk (*) after the strain number. Results of the pairwise sequence similarity are illustrated on the dashed lines between the query strain and its closely-related species (arrows point to the reference strains).

Figure 4. Trichoderma macrofasciculatum A-C cultures on different media incubated at 25 ° C for 7 days (A on PDA B on MEA C on CM) D-G conidiophores and phialides H conidia with guttules. Notes: A, D, E from WT 37810 B, C, F, G from WT 37805. Scale bars: 10 μm (D-H).