Tetraploa yunnanensis W. Dong, H. Yang & H. Zhang
Index Fungorum number: IF557937; Facesoffungi number: FoF09282
Etymology: referring to Yunnan province, where the holotype was collected
Holotype: MFLU 19-0524
Saprobic on submerged wood. Sexual morph: Undetermined. Asexual morph: Mycelium superficial. Conidiophores absent. Conidiogenous cells monoblastic. Conidia 30–50 × 16–22 μm (x̄ = 43 × 19 μm, n = 10), solitary, short to long cylindrical, brown to dark brown, verrucose, consisting of 2–3 columns of 7.5–10 µm wide, 4–6-celled, with 1–3 appendages. Appendages 25–83 µm long, 4–5.5 µm wide at the base, 1.5–2.5 µm wide at the apex, 1–5-septate, brown, smooth, unbranched, straight. (Descriptions from Dong et al. 2020)
Cultural characteristics: Conidia germinated on PDA within 24 hours. Colonies on PDA reaching 20–25 mm diam. in 18 days at 25 °C, with dense, floccose, brown mycelium on the surface, reverse brown to dark brown, with undulate, pale brown margin.
Material examined: CHINA, Yunnan Province, Puzhehei Wetland, 24°8ʹ32ʺN, 104°6ʹ58ʺE, on submerged wood, 12 May 2018, H. Yang, P13 (MFLU 19-0524, holotype), ex-type living culture MFLUCC 19-0319; Thailand, Chiang Mai Province, on submerged wood, 9 February 2018, G.N. Wang, A66 (MFLU 18-0959), living culture MFLUCC 18-0652.
Notes: Tetraploa yunnanensis clusters with a strain of T. sasicola (NCYUCC 19-0371) with high bootstrap support (Dong et al. 2020). Tetraploa sasicola NCYUCC 19-0371 (MFLU 19-2698) is an ascomycetous species characterized by hyaline to yellowish brown ascospores without appendages (Hyde et al. 2020). Although asexual morph of NCYUCC 19-0371 was not formed in culture (Hyde et al. 2020), phylogeny clearly separates them as distinct species (Dong et al. 2020). Dong et al. (2020) found that NCYUCC 19-0371 clusters in a separated clade between Tetraploa yunnanensis (MFLUCC 19-0319, ex-type strain) and T. sasicola (KT 563, ex-type strain) with high bootstrap support. Comparison of single LSU and ITS sequence data also shows 14 and 25 nucleotide differences between NCYUCC 19-0371 and KT 563, respectively. This indicates that NCYUCC 19-0371 and KT 563 are phylogenetically different species (Jeewon and Hyde 2016).
NCYUCC 19-0371 differs from KT 563 in having larger asci (97–109 × 22–23 μm vs. 61–100 × 9–13 μm) and wider ascospores (24–29 × 4–14 μm vs. 22.5–34 × 3–5 μm). Additionally, NCYUCC 19-0371 has hyaline to yellowish brown ascospores without appendages, while KT 563 has hyaline ascospores with a narrow sheath drawn out at both ends, which is longer at the apex than the one at the base (Tanaka et al. 2009; Hyde et al. 2020). NCYUCC 19-0371 bearing the name Tetraploa sasicola is probably a novel species, but the introduction should be performed with re-examination of the specimen MFLU 19-2698 or new collections. (Notes from Dong et al. 2020)