Clonostachys eriocamporesii

Clonostachys eriocamporesii R.H. Perera & K.D. Hyde, in Hyde et al., Fungal Diversity 100: 197 (2020)

Index Fungorum number: IF556897         Facesoffungi number: FoF 06964

Saprobic on stems of Pennisetum polystachion. Stromata absent. Sexual morph: Ascomata 90–150 × 80–170 μm (x̄ = 118 × 119 μm), perithecial, superficial, solitary to gregarious, globose to subglobose, not collapsing or sometimes slightly laterally pinched when dry, yellowish orange, KOH-, slightly papillate, surface warted. Ostiole periphysate. Perithecial warts 30 μm high, mostly developed in the upper part of the ascomata, off-white to yellowish white, cells angular to globose with unevenly thickened walls. Peridium 15–21 μm thick, composed of two regions: outer region 5–11 μm, 2–3 cells thick, cells angular to globose, with uniformly thickened walls, merging with the cells of the warts, vacuoles not observed; inner region 9–17 μm thick, composed of flat hyaline cells. Paraphyses absent. Asci 40–52.5 × 7.4–9.4 μm (x̄ = 44.8 × 8 μm, n = 20), 4-, 6- or 8-spored, unitunicate, cylindrical to narrowly clavate, apex flat with somewhat rounded edges, short pedicellate, apical ring J-. Ascospores 10–12.7 × 2.7–4.2 μm (x̄ = 11.3 × 3.5 μm, n = 30), 1–2-seriate, hyaline, median or submedian, 1-septate, equilateral or inequilateral, slightly constricted at the septum, ellipsoidal to occasionally subglobose, multi-guttulate, smooth-walled. Asexual morph: Undetermined.

Culture characteristics: Ascospores germinating on PDA within 12 h. Colonies growing on PDA, reaching up to 20 cm in 7 days at 28 °C, surface effused, smooth, margin entire to undulate, aerial mycelium abundant, zonate, white, reverse white.

Host and habitat: On dead stems of Pennisetum polystachion (Hyde et al. 2020)

Known host and distribution: Thailand

Material examined: THAILAND, Southern Thailand, on dead stems of Pennisetum polystachion (L.) Schult. (Poaceae), 11 November 2017, A. Karunarathne, Bion 78 (MFLU 18-2718, holotype), ex-type living culture MFLUCC 19-0486.

GenBank Accession No: ITS: MN699133, LSU: MN699128.

Notes: The new strain MFLUCC 19-0486 clusters with the ex-type of Clonostachys epichloë Schroers (CBS 101037) and C. parva (Schroers) Rossman, L. Lombard & Crous (CBS 997.69) with high statistical support (100% ML, 1.00 BYPP). DNA sequences of C. eriocamporesii and C. epichloë (CBS 101037) differ in 6 nucleotides of the ITS region (1.1%), and 4 nucleotides of LSU region (0.8%). DNA sequences of new fungus and ex-type of C. parva (CBS 997.69) differ in 8 nucleotides of the ITS region (1.6%), and 10 nucleotides of LSU region (1.2%). Clonostachys eriocamporesii is similar to C. epichloë and C. parva in having perithecial warts (Schroers 2001). However, it can be distinguished from C. epichloë by its larger ascospores (10–12.7 versus 9–10.8 μm) (Schroers 2001). Clonostachys eriocamporesii can be distinguished from C. parva in having smooth-walled, smaller ascospores (10–12.7 versus 12.2–13.4 μm) while C. parva has finely spinulose ascospores (Schroers 2001). We therefore, introduce C. eriocamporesii as a novel taxon.