Trichoderma purpureum W.T. Qin & W.Y. Zhuang, 2017

Qin, Wen-Tao & Zhuang, Wen-Ying, 2017, Seven new species of Trichoderma (Hypocreales) in the Harzianum and Strictipile clades, Phytotaxa 305 (3), pp. 121-139 : 131-133

Trichoderma purpureum W.T. Qin & W.Y. Zhuang , sp. nov. FIGURE 6

Etymology:— The specific epithet refers to the purplish stromata.

MycoBank: MB 816633

Type: — CHINA. ANHUI: Jinzhai, Tiantangzhai, 900–1000 m, on dead barks, 24 Aug 2011, W.Y. Zhuang, H.D. Zheng, Z.Q. Zeng & S.L. Chen 7870 (holotype HMAS 273787).

Stromata solitary or aggregated in a small groups, pulvinate, discoidal or substipitate, smooth, purplish red to dark purple, margin free, when fresh 0.9–2.5 mm diam, 0.8–1.3 mm thick. Ostiolar dots obvious, numerous, dark grey to black. Rehydrated stromata turning orange red in 3% KOH.

In section, cortical tissue of textura angularis, 10–21 μm thick, turning reddish brown in 3% KOH, cells brownish yellow, thin-walled, 5–10.5 × (4.7–)5–7.4(–8) μm (n = 30); subcortical tissue of textura angularis mixed with textura intricata, cells hyaline to light yellow, thin-walled, 4–8 × 3.5–7.5 μm (n = 30), hyphae hyaline to light yellow, thin-walled, 3.5–5.3 μm (n = 30) wide; subperithecial tissue of textura angularis, cells hyaline to light yellow, thin-walled, (8–)8.5–30(–32) × (7.5–)8.5–24(–27) μm (n = 30); tissue at the base of textura angularis mixed with textura intricata, cells hyaline to light yellow, thin-walled, 5.3–8.5 × 5.3–7.5 μm (n = 30), hyphae hyaline to light yellow, thin-walled, (4.7–)5–7.5(–8) μm (n = 30) wide. Perithecia subglobose or flask-shaped, numerous, (210–)226–262(–289) × 153– 197(–250) μm (n = 30); peridium yellow in lactic acid, turning brownish yellow in 3% KOH, 9.5–13.2 μm thick at flanks, 10.5–13.2 μm thick at the base (n = 30). Ostioles non-papillate, (61–)66–79 μm high, 29–34 μm wide at the apex (n = 30). Asci cylindrical, 93–105(–108) × 4.7–6 μm, with a stipe (4–)13–20(–26) μm long (n = 40). Part-ascospores green, spinulose or verruculose, dimorphic, distal cells subglobose to slightly ovoid, 4.2–5.2 × 4.2–4.5 μm, l/ w 1.0 –1.2; proximal cells globose, subglobose to nearly wedge-shaped, (3.7–)3.9–5.2(–5.7) × 3.7–4.5 μm, l/ w 1.0 –1.4 (n = 40).

Notes:— Trichoderma purpureum is most closely related to T. epimyces , but the latter fungus possesses much larger, brown-orange, reddish to olive brown stromata [1–14 mm diam.], and smaller perithecia [(115–)170–230(–260) × (100–)120–180(–240) μm] ( Jaklitsch 2009).

Species having purplish stromata and green ascospores are rare in the genus except for T. tawa belonging also in the Harzianum clade. Trichoderma tawa differs in that its rehydrated stromata do not change color in KOH, peridium is hyaline, and ascospores are larger [distal cells (4.5)5.3–5.5(–6.7) × (3.5–)4.5–5.0(–5.8) μm, proximal cells (4.3–)5.5– 6.0(–7.5) × (3.0–)4.0–4.5(–5.5) μm] ( Chaverri & Samuels 2003). These two species are remotely related according to the phylogenetic analyses ( Figure 1 ).

Figures

FIGURE 1. Maximum parsimony phylogram reconstructed from the combined sequences of RPB2 and TEF1-α. MPBP (left) above 50% and BIPP (right) above 90% are indicated at the nodes. New species proposed are indicated in boldface. TreeBASE no. S19229.

FIGURE 6. Trichoderma purpureum (HMAS 273787). a–e. Stromata on nature substrate. f. Rehydrated mature stroma; g. Rehydrated stroma in 3% KOH. h. Longitudinal section of a stroma. i. Perithecium in section. j. Cortical and subcortical tissue in section. k. Subperithecial tissue in section. l. Stroma base in section. m. Ascus with part-ascospores. Scale bars: a = 2 mm; b, c = 1 mm; d–g = 0.4 mm; h = 200 μm; i = 50 μm; j–l = 20 μm; m = 5 μm.