Clonostachys linzhiensis S. C. He, K. D. Hyde & Q. Zhao, 2025

He, Shucheng, Thiyagaraja, Vinodhini, Bhunjun, Chitrabhanu S., Chomnunti, Putarak, Dissanayake, Lakmali S., Jayawardena, Ruvishika S., Yang, Hongde, Zhao, Yun Wei, Al-Otibi, Fatimah, Zhao, Qi & Hyde, Kevin D., 2025, Morphology and multi-gene phylogeny reveal three new species of Clonostachys and two combinations of Sesquicillium (Bionectriaceae, Hypocreales) from Xizang, China, MycoKeys 115, pp. 43-66 : 43-66

Clonostachys linzhiensis S. C. He, K. D. Hyde & Q. Zhao sp. nov.

Fig. 2

Etymology.

The species epithet is derived from Linzhi City, where the holotype was collected.

Typification.

China • Xizang Autonomous Region, Linzhi City , Motuo County (29°11'N, 95°8'E, 1561 m), on the lower part of the leaves of Houttuynia cordata , July 27, 2022, collected by Hong-De Yang, YHD 691 (holotype: KUN-HKAS 133179 ); ex-type living culture: KUNCC 24-18528 ). GenBank: ITS: PQ 522504 , 28 S: PQ 634391 , tef 1: PQ 650477, tub 2: PQ 650459 .

Description.

Sexual morph: Not observed. Asexual morph: Hyphomycetous. Colonies on the WA, raised, medium sparse, rough, white at apex. Conidiophores mononematous, erect, simple, verticillium-like, straight or flexuous, branched, smooth-walled, thin-walled, septate, hyaline, produce globose cells at the apex, terminal branches developing into phialides, 110–232 × 2.5–3.9 μm (x ̄ = 170 × 3.2 μm, n = 20). Phialides polytretic, terminal on branches, phialides cylindrical but slightly tapering towards the tips, aseptate, hyaline, smooth, thin-walled, terminal developing into conidia, 15.3–23.8 × 1.5–3.3 μm (x ̄ = 19.8 × 2.2 μm, n = 20). Conidia amerospores, solitary, acrogenous, simple, doliiform to ellipsoidal, smooth, thin-walled, aseptate, hyaline, 3.9–5.7 × 2.2–3.2 μm (x ̄ = 4.7 × 2.6 μm, n = 30).

Culture characteristics.

Colonies on PDA reaching 5.0– 5.5 cm after 20 days of incubation at 25 ° C, white above, pale yellow reverse, medium spare, concave in the center, convex around, hairy, lobate, velvety, ciliate, not pigment produced,

Habitat.

Leaves of Houttuynia cordata .

Additional material examined.

China • Xizang Autonomous Region, Linzhi City , Motuo County (29°11'N, 95°8'E, 1561 m), on the lower part of the leaves of Houttuynia cordata , July 27, 2022, collected by Hong-De Yang, HSC 983 (isotype: KUN-HKAS 133180 ); ex-isotype living culture: KUNCC 24-18529 ). GenBank: ITS: PQ 522505 , 28 S: PQ 634392 , tef 1: PQ 650478, tub 2: PQ 650460 .

Notes.

In the phylogenetic analysis, Clonostachys linzhiensis shared a close phylogenetic relationship with C. aranearum and C. motuoensis (Fig. 1 ). Clonostachys linzhiensis shares similar morphology to C. aranearum and C. motuoensis in having mononematous, erect, verticillium-like conidiophores that are straight or flexuous, smooth-walled, hyaline, phialides are polytretic, terminal, flask-shaped, aseptate, hyaline, smooth and the conidia are amerospores, acrogenous, ellipsoidal, aseptate, hyaline ( Wan et al. 2016). However, Clonostachys linzhiensis ( HKAS 133179 and HKAS 133180 ) has larger conidiophores (L / W ratio: 53 vs 12 and L / W ratio: 53 vs 35) and longer phialides (L / W ratio: 9 vs 6.7 and L / W ratio: 9 vs 4.7) in comparison to C. aranearum and C. motuoensis . Furthermore, the ITS and tub 2 sequence of Clonostachys linzhiensis differs from C. aranearum which revealed 13 / 510 (2.5 %) and 7 / 291 (2.4 %) base pair differences, respectively. Based on the differences in morphology (larger conidiophores and longer phialides) and phylogeny, along with the guidelines of Maharachchimbukura et al. (2021), we identify our specimen as a new species, C. linzhiensis .

Figures

Figure 1. Phylogenetic tree generated from maximum likelihood analysis based on a combined 28 S tef 1, rpb 2, ITS and tub 2 sequence dataset. Bootstrap support values for ML equal to or greater than 70 % and PP equal to greater than 0.90 are indicated at the nodes as MLB / BYPP. The ex-type strains are in bold, while the new isolates are in red, and the synonymizing taxa are indicated in green.

Figure 2. Clonostachys linzhiensis (HKAS 133179, Holotype) a, b culture on PDA (a above b below) c colonies on WA d – g conidiophores h, i phialides j – q conidia. Scale bars: 50 μm (d – g); 50 μm (h, i); 5 μm (j – q).