Trichoderma clavaticapitatum Z.Q. Zeng, X.H. Wang & W.Y. Zhuang

Zeng, Zhao-Qing, Wang, Xiang-Hua & Zhuang, Wen-Ying, 2024, New species and new Chinese record of Hypocreaceae from China, Phytotaxa 650 (1), pp. 93-102 : 96-97

Trichoderma clavaticapitatum Z.Q. Zeng, X.H. Wang & W.Y. Zhuang , sp. nov.

Fig. 3

Fungal Names: FN 571880.

Etymology: —The specific epithet refers to the headlike fertile part of stipitate stromata.

Typification:— CHINA. Yunnan Province: Deqin County, Baima Snow Mountain National Nature Reserve, on mossy humus in mixed forest of Abies and Rhododendron trees, N 28.325506 E 99.101091, alt. 3954 m, 6 October 2020, X.H. Wang et al. 9699 (holotype HKAS 131918 ).

Description:— Stromata simple, unbranched, clavate, 12–30 mm long; fertile part capitate, distinctly laterally wrinkled to surface nearly smooth, beige to light brown when fresh, yellow brown to olivaceous brown when dry, KOH–, 6–12 mm long, 4–8 mm wide at apex; sterile part narrower than the fertile part, light beige, 6–18 mm long, 1.5– 2.5 mm wide. Stromatal surface faintly tuberculate due to papillate perithecial elevations. Ostiolar openings visible, 30–78 μm high, 40–69 μm diam. In section, cortical tissue of textura angularis to textura globulosa, 25–50 μm thick, cells hyaline to light brown, 2.5–8 × 2–6 μm; subcortical tissue of textura angularis, 12.5–38 μm thick, cells hyaline to light yellow, 5–10 × 2–4 μm; subperithecial tissue of textura angularis to epidermoides, cells hyaline to light yellow, 5–10 × 2–4 μm. Perithecia flask-shaped, subglobose to oblong, 255–343 μm high, 137–255 μm diam.; peridium 8.5– 13 μm thick at flanks, 10–23 μm thick at the base. Papilla prominent, blunt to truncate, brown, 20–30 μm high, 40–69 μm wide. Asci cylindrical, containing 16 disarticulate part-spores, 65–88 × 2–4 μm. Part-ascospores hyaline, smooth, uniseriate, dimorphic, distal cells globose to subglobose, rarely oblong, 3–5 × 2.9–4 μm; proximal cells ellipsoidal to oblong, rarely subglobose, 3–5 × 2–3.1 μm. Asexual state unknown.

Notes:— Among the stipitate species of this group, T. clavaticapitatum is similar to T. brevipes (Mont.) Samuels , H. capitata Samuels , T. pezizoides (Berk. & Broome) Samuels et al. , and T. poronioideum (Möller) Samuels in having stromata with an expanded cap ( Samuels & Lodge 1996, Chamberlain et al. 2004). Nevertheless, T. clavaticapitatum can be easily distinguished by its long, stipitate, erect stromata with a conspicuous head-like fertile part. Additionally, T. clavaticapitatum also resembles T. leucopus in gross morphology of fruiting bodies which are of erect stromata, that do not change colour in KOH, and its perithecia are flask-shaped or subglobose with a conspicuous ostiole, containing cylindrical asci and disarticulated ascospores ( Chamberlain et al. 2004, Jaklitsch 2011). However, T. leucopus differs in having longer clavate stromata (20–41 mm long), smaller perithecia (200–310 μm high), and wider asci (3.3–5.3 μm wide). Sequence comparisons indicate that ITS of T. clavaticapitatum (HKAS 131918) differs from that of T. leucopus (CBS 122495) by 24 bp in a total length of 586 bp; RPB2 and TEF1 of the former differ from those of the latter by 51 bp and 80 bp, respectively, among 1127 bp and 317 bp.

Figures

FIGURE 3. Trichoderma clavaticapitatum a. Fresh stromata.b Dry stromata.c. Close-up view of perithecia.d. Perithecia after rehydration. e. Median section through stroma. f. Section of cortical tissue. g. Subperithecial tissues in section. h. Perithecia in section. i–m. Asci with part-ascospores. Scale bars: a, b = 1 cm, c = 0.5 mm, d = 1 mm, e–h = 50 μm, i–m = 10 μm.