Trichoderma gansuanum Z.Q. Zeng & W.Y. Zhuang, 2020

Zeng, Zhao-Qing, Zheng, Huan-Di, Wang, Xin-Cun, Wei, Sheng-Long & Zhuang, Wen-Ying, 2020, Ascomycetes from the Qilian Mountains, China - Hypocreales, MycoKeys 71, pp. 119-137 : 119

Trichoderma gansuanum Z.Q. Zeng & W.Y. Zhuang sp. nov. Figure 4

Holotype.

China. Gansu Province, Shandan, Yanzhishan, on mossy humus, 25 August 2018, Z.Q. Zeng, H.D. Zheng & X.C. Wang 12100 (HMAS 279687).

Paratypes.

China. Gansu Province, Shandan, Yanzhishan, on mossy humus, 25 August 2018, Z.Q. Zeng, H.D. Zheng 12043, 12044 (HMAS 279684, 279685), on mossy humus, 25 August 2018, X.Z. Liu & Z.Q. Zeng 12045 (HMAS 279686); Wuwei, Chashugou, on mossy humus, 26 August 2018, Z.Q. Zeng, H.D. Zheng & X.C. Wang 12104, 12105 (HMAS 279688, 279689); Wuwei, Xiama, on mossy humus, 26 August 2018, Z.Q. Zeng, H.D. Zheng & X.C. Wang 12162, 12163 (HMAS 279690, 279691).

Etymology.

The specific epithet refers to the type locality.

Description.

Stromata simple, rare dichotomously branched, clavate, 20-54 mm long. Fertile part clavate, 5-18 mm long, 1.2-4 mm wide at apex, only slightly broader than stipe, distinctly laterally compressed or longitudinally furrowed, gradually tapered downwards, reddish brown to brownish orange, KOH+; sterile part 15-36 mm long, 1-3 mm wide, beige to cream KOH+. Stromatal surface slight tuberculate from papillate perithecial elevations. Ostiolar openings visible, 30-58 μm high. In section, cortical tissue of textura angularis,15-35 μm thick, cells hyaline to light yellow, 5-15 × 2-3 μm; subcortical tissue of textura angularis, 8-28 μm thick, cell hyaline to light yellow, 8-15 × 3-5 μm; subperithecial tissue of textura epidermoidea, rare textura angularis, cells hyaline to light yellow. Perithecia globose to subglobose, 196-206 × 167-235 μm; peridium 8-18 μm thick at flanks, 9-20 μm thick at the base. Papilla prominent, blunt or truncate, brown, 15-35 μm high, 18-43 μm wide at the base. Asci subcylindrical, 50-80 × 3-4 μm. Part-ascospores green, spinulose, dimorphic, distal cells globose, rarely ellipsoidal, 2.5-4 × 2.5-4 μm; proximal cells ellipsoidal to oblong, 3-5.5 × 2.5-3 μm. Asexual state unknown.

Distribution.

China.

Notes.

Among the known stipitate species of Trichoderma , T. gansuanum resembles T. nybergianum in habitat and having simple, clavate, erect stromata, cylindrical asci and disarticulating ascospores ( Chamberlain et al. 2004). Trichoderma gansuanum differs from the latter in shorter ascomatal stipe (20-54 mm vs 22-220 mm long), smaller perithecia (196-206 × 167-235 μm vs 180-450 × 65-315 µm), asci (50-80 × 3-4 μm vs 63-130 × 3.2-7.5 μm), and part-ascospores (distal: 2.5-4 × 2.5-4 μm vs 3-6 × 3-4.5 μm; proximal: 3-5.5 × 2.5-3 μm vs 3-6 × 2.5-4.5 μm) ( Chamberlain et al. 2004). Sequence comparisons reveal that there are 25 bp and 16 bp divergences between the two species in the regions of RPB2 and TEF1. Both morphological and molecular data support distinguish them at the species level. The asexual state of T. gansuanum remains unknown until a culture is available.

Figures

Figure 4. Trichoderma gansuanum a fresh stroma b dry stroma c stromatal surface d color of stroma after rehydration e median section through stromata f cortical tissue in section g subperithecial tissues in section h perithecia in section i ascus with ascospores j-m ascus with part-ascospores a from HMAS 279684, b-m from HMAS 279687. Scale bars: 1 cm (a); 1 mm (b-d); 50 μm (e-f); 10 μm (g-m).