Trichoderma nordicum 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 nordicum G.Z. Zhang sp. nov.

Fig. 5

Etymology.

“nord” means found in the north of China.

Holotype.

China, Beijing, Yu-yuan-tan Park, 43 m (altitude), isolated from soil, 27 October 2016, G.Z. Zhang (Holotype WT 13001), ex-type culture ACCC 39713.

Diagnosis.

Phylogenetically Trichoderma nordicum is related to T. paratroviride , but the sequence similarities of rpb2 and tef1 -α were 98.15% and 94.43%, respectively. That does not meet the sp ∃!(rpb2 99≅ tef1 97) standard for T. paratroviride or other known Trichoderma species. Morphologically, conidiophores of T. paratroviride consisting of a main axis and often distantly-spaced side branches, not re-branching. Conidiophores of T. nordicum are branched in a more complex manner; conidia are larger than those of T. paratroviride .

Teleomorph.

Unknown.

Growth optimal at 25 °C, slow or limited at 30 °C, absent at 35 °C. Colonies grew fast on PDA, CMD and MEA and slow on SNA. Colony radius after 72 h at 25 °C 67-71 mm on PDA, 68-71 mm on CMD, 51-55 mm on MEA and 21-24 mm on SNA. Aerial mycelia sparse on PDA after 72 h at 25 °C under 12 h photoperiod and conidiation developed within 48 h beginning at the inoculation point and progressed around, grey-white at first and slowly turning green. Diffusing pigment or distinctive odour absent. Aerial mycelia sparse and flocculence on MEA after 72 h at 20 °C under 12 h photoperiod. Conidia developed within 48 h beginning near the colony margin on MEA, grey-white at first and slowly turning green, transparent liquid secreted. Aerial mycelia few on SNA and CMD after 72 h at 25 °C, conidia formed around the inoculation point and in distinct concentric rings after 96 h under 12 h photoperiod on SNA and CMD, diffusing pigment not produced. Conidiophores and branches narrow and flexuous, tending to be regularly verticillate forming a pyramidal structure, each branch terminating in a cruciate whorl of up to five phialides. Phialides, lageniform, (6.2-)7.2-10.3(-12.9) × (2.6-)2.9-3.2(-3.4) μm (mean = 8.8 × 3.1 μm), 1.6-2.3 μm (mean = 1.9 μm) near the base; phialide length/width ratio (2.1-)2.4-3.4(-4.3) (mean = 2.9). On PDA, phialides curved, distinguished from those on other media. Conidia, globose to obovoidal, (4.1-)4.4-4.8(-5.0) × (4.0-)4.1-4.4(-4.6) μm (mean = 4.6 × 4.3 μm), length/width ratio 1.0-1.2 (mean = 1.1). Chlamydospores sometimes present, (8.7-)9.8 × 10.4(-12.5) μm.

Distribution.

China, Beijing and Hebei.

Additional specimen examined.

China. Hebei, Bai-yang Lake, 19 m (altitude), isolated from soil, 15 September 2016, J.S. Li (WT 61001).

Notes.

Phylogenetically, Trichoderma nordicum is related to T. paratroviride (Fig. 1 ), but the sequence similarities of rpb2 and tef1 -α were 98.15% and 94.43%, respectively. That does not meet the sp ∃!(rpb2 99≅ tef1 97) standard for T. paratroviride or other known Trichoderma species. Morphologically, conidiophores of T. paratroviride consist of a main axis and often distantly-spaced side branches, not re-branching. Conidiophores of T. nordicum are branched in a more complex manner; conidia are larger than those of T. paratroviride ( Jaklitsch and Voglmayr 2015).

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 5. Trichoderma nordicum A-D cultures on different media at 25 ° C after 10 days (A on PDA B on MEA C on CMD D on SNA) E-G, I, J conidiophores and phialides H conidia. Notes: E on PDA F-J on MEA A-D from WT 13001 E-J from WT 61001. Scale bars: 10 μm (E-J).