Trichoderma zeloharzianum Z.F. Yu & X. Du

Qiao, Min, Du, Xing, Zhang, Zhe, Xu, JianPing & Yu, ZeFen, 2018, Three new species of soil-inhabiting Trichoderma from southwest China, MycoKeys 44, pp. 63-80 : 63

Trichoderma zeloharzianum Z.F. Yu & X. Du sp. nov. Figure 4

Etymology.

Greek zelo-, meaning emulation + harzianum, referred to Trichoderma harzianum

Diagnosis.

Characterised by pyramidal conidiophores, verticillate branches, ampulliform to lageniform phialides (5.5-10.0 × 2.5-3.5 μm) and subglobose to globose, thin-walled conidia (2.7-3.1 × 2.4-2.6 μm). Differs from T. harzianum by verticillate branches, 3-6 whorled phialides on terminal of each branch and thinner conidia. Differs from T. lixii by verticillate and compact branches, more terminal phialides on main axis and smaller conidia. Differs from T. simmonsii by verticillate branches and longer conidia.

Type.

CHINA. Yunnan: Qujing City, Luliang county, 25°05'25"N, 103°56'42"E, 1800 m alt., in soil, Jul 2007, Z.F. Yu (YMF 1.00268, holotype), Ex-type culture CGMCC 3.19082.

Description.

On CMD after 72 h, colony radius 59-62 mm, mycelium covers the plate after 96 h at 25 °C; 43-45 mm at 30 °C and 46-52 mm at 35 °C after 72 h. Colony yellowing, margin distinct. Aerial hyphae fertile and conspicuous, hairy radial, distributed on surface, green conidial production noted after 4 days.

On PDA after 72 h, colony radius 57-58 mm, mycelium covers the plate after 96 h at 25 °C. Covering the plate at 30 °C and 38-42 mm at 35 °C after 72 h. Colony white, margin distinct. Aerial hyphae abundant, hairy to floccose, denser around central disc. Green conidiation noted after 3 days.

On SNA after 72 h, radius 59-65 mm, mycelium covers the plate after 144 h at 25 °C, 64-65 mm at 30 °C and 29-37 mm at 35 °C after 72 h. Aerial hyphae sparsely, slightly radial and conspicuous zonate. Conidiophores well defined, branching 2-3 times in a pyramidal fashion. Branches paired or a whorl of 3-4, the distance between neighbouring second branches is 16.0-39.0 μm, base 3.0-4.0 μm wide, each branch terminating in a whorl of 3-6 phialides, phialides ampulliform to lageniform, often verticillated up to 5 around the main axis near the apex, rarely singly arising, (4.5)5.5 –10.0(– 11.0) × 2.5 –3.5(– 4.0) μm, length/width ratio (1.4 –)1.8–3.4(– 3.6). Conidia smooth on surface, subglobose to globose, sometimes obovoid, (2.6-) 2.7 –3.1(– 3.2) × (2.3-) 2.4 –2.6(– 2.7) μm, length/width ratio (1.0 –)1.1–1.3(– 1.4).

Habitat and distribution.

In soil from tobacco rhizosphere in part of cultivated land of south-western China.

Teleomorph.

Not known

Remarks.

Trichoderma zeloharzianum forms a single branch with T. harzianum Rifai as sister clade. Morphologically, T. harzianum is similar to T. zeloharzianum in their shape of conidiophores and phialides, but the branches of T. harzianum are opposite of each other and each branch terminating in a whorl of 2-5 phialides ( Chaverri et al.2015), while T. zeloharzianum is clearly distinguishable by having verticillated branches and 3-6 terminal whorled phialides. In addition, the conidia of T. harzianum are generally wider [(2.0−)2.5−3.0 (−3.7) μm] than those of T. zeloharzianum .

Trichoderma lixii differs from T. zeloharzianum also by having opposing pairs of branches and fewer terminal phialides (2-4) on main axis. Beyond that, closely spaced branches are common in T. lixii ( Chaverri et al.2015), whereas for T. zeloharzianum , neighbouring branches are more compact and the conidia of T. lixii are usually larger [(2.5−)3.0−3.5 (−3.7) × (2.2−)2.5−3.2(−3.5) μm] than those of T. zeloharzianum .

Trichoderma simmonsii is also distinguished obviously from T. zeloharzianum , except their differences about opposing branches ( Chaverri et al. 2015), the phialides are more stout and shorter ((4.2−)5.2−6.5 (−9.0) μm) than those of T. zeloharzianum . Furthermore, T. simmonsii is commonly constricted below the tip to form a narrow neck ( Chaverri et al. 2015); however, this character is not found in T. zeloharzianum .