Trichoderma pyrrosiae Li Hua & Senan., sp. nov.

Index Fungorum number: IF 900453; MycoBank number: MB 900453; Facesoffungi number: FoF 14204; Fig. 1

Isolated from leaves of Pyrrosia lingua (Thunb.) Farwell. Sexual morph: Not observed. Asexual morph: Conidiophores straight or slightly curved, many, often branched in pairs, branched 1–2 times, base width 2–4 μm, distance between adjacent two branches (5.5–)7–16(–24.5) μm, branches usually perpendicular to the main axis, terminating in 3–5 branches. Phialides (4–)5–9 × 2.5–4 μm, l/w ratio 2:1, ampulliform to lageniform in whorls, sometimes directly from the main axis. Conidia (3.5–)4–5×3–4 μm, aspect ratio 1.5:1, spherical to subglobose, thin-walled, white, smooth.

Material examined – China, Guangdong Province, Guangzhou City, Baiyun Mountain, 23° 11′ 13″ N 113° 17′ 51″ E, isolated from Pyrrosia lingua (Polypodiaceae), 16 August 2021, Li Hua (MHZU 22-0159, holotype); ex-type culture, ZHKUCC 22-0297.

Culture characteristics – Colonies on PDA reaching 8 cm diameter after 3 days at 25 °C, circular, smooth margin, green in the center, white at the margin, aerial hyphae hairy to floccose, dense at center, relative sparse at the margin. Chlamydospores or diffusing pigments not formed. The wood smell was occurred.

GenBank numbers – ITS: OQ980189, OQ980190 

Notes – Our trichoderma-like species grouped with Trichoderma asperellum in the combined ITS, rpb2, and tef1-α sequence analyses (Fig. 2) with ML/BI=96%/1.00 statistical support. However, our collection morphologically differs from the phylogenetically nearest species T. asperellum by its sterile secondary branches and the short phialides (5–9 vs 7–11.5). The nucleotide differences of rpb2 and tef1-α between our collection and T. asperellum revealed 1.31% and 1.5% respectively and ITS sequences are identical. Therefore, we introduce our collection as Trichoderma pyrrosiae sp. nov.

Figure 1 – Trichoderma pyrrosiae (MHZU 22-0159, holotype). a Surface view of culture on PDA. b Reverse view of culture on PDA. c Conidial mass on PDA. d–e Conidiophores, phialides and attached conidia. f–j Conidia. Scale bars: d–e=10 cm, f–g, i–j=5 μm, h=15 μm

Figure 2 – Phylogenetic tree derived from maximum likelihood analyses of a combined ITS, rpb2 and tef1-α sequences. The aligned dataset comprised of 2626 characters including gaps (ITS=463, rpb2=1067, tef1-α=1,094). A best scoring RAxML tree was established with a final ML optimization likelihood value of − 20,692.436886. The matrix had 580 distinct alignment patterns with 15.62% undetermined characters or gaps. Estimated base frequencies were found to be: A=0.233296, C=0.282631, G=0.255967, T=0.228106; substitution rates AC=0.898272, AG=3.638367, AT=0.947951, CG=0.678561, CT=T: 5.576378, GT=1.0. Protocrea farinose (CBS 121551) and P. pallida (CBS 299.78) were used as outgroup taxa. Newly generated isolates are indicated in blue bold. Bootstrap support for ML≤75% and BI equal to or greater than 0.90 are given at the nodes