Dictyocheirospora nabanheensis Tibpromma & K. D. Hyde

Dictyocheirospora nabanheensis Tibpromma & K. D. Hyde, Fungal Diversity 93: 10 (2018) Fig. 2 Description. Saprobic on submerged decaying wood in the Dulongjiang River. Sexual morph Undetermined. Asexual morph: Hyphomycetous. Colonies on natural substrate in small, scattered clusters, dark brown, velvety. Mycelium composed of immersed or partly superficial, hyaline to pale brown, septate, branched hyphae. Conidiophores micronematous, mononematous, septate, smooth, thin-walled, cylindrical, reduced to conidiogenous cells. Conidiogenous cells 8–13 × 3–5 μm (x ̄ = 13.8 × 4.2 μm, n = 10), holoblastic, monoblastic, integrated, cylindrical, hyaline to pale brown, smooth-walled. Conidia 31–36 × 14–16 μm (x ̄ = 33 × 15 μm, n = 36), solitary, ellipsoid to cylindrical, cheiroid, with a basal connecting cell, brown to yellow – brown, smooth-walled, euseptate, with discoid individual cells arranged in 6 compact rows (x ̄ = 34.8 × 5.8 μm, n = 30) closely clustered at the apex, each row with 6–8 cells compactly and linearly clustered, with 1–2 rounded to cylindrical hyaline, 6–10 × 5–7 μm, appendages arising from near the middle of conidial rows. Culture characteristics. Conidia germinating on WA within 12 h and germ tubes were produced at the basal region (Fig. 2 f). Colonies on PDA at 22 ° C, circular, white at margin around the edge and light gray in the center, raised on surface, with white, pale orange concentric rings, yellow – orange in the middle on the reverse side. Material examined. China • Yunnan Province, Dulongjiang River, on submerged decaying wood, 2 May 2023 (Altitude: 1422 m, 27.793592°N, 98.330416°E), Ying Wang, S 4719 (KUN-HKAS 135951), living culture, KUNCC 23-15886. Notes. The newly collected fungus has closely clustered terminal cells at the apex of the conidia, which is similar to those of the genus Dictyocheirospora. Phylogenetic analysis of the combined ITS, LSU, and tef 1 - α sequence data showed that the new strain KUNCC 23-15886 clustered sister to the ex-type strain of D. nabanheensis (KUMCC 16-0152) with 79 % ML and 0.96 PP statistical support (Fig. 1). Morphologically, KUNCC 23-15886 resembles D. nabanheensis in having conidia with hyaline, globose to subglobose appendages in the middle region. Dictyocheirospora nabanheensis (KUMCC 16-0152) differs from KUNCC 23-15886 in having slightly larger conidia (38 × 20 μm vs. 33 × 15 μm) (Tibpromma et al. 2018 a; Shen et al. 2022 b) and with more cells in each row (6–10 cells vs. 6–8 cells) (Tibpromma et al. 2018 a; Shen et al. 2022 b). However, there are only 0.83 % (4 / 480) differences between ITS sequence data. Therefore, we identified our collection as D. nabanheensis. The type of D. nabanheensis was found on dead leaves of Pandanus sp. in a terrestrial habitat in Yunnan, China, and the strain of MFLUCC 22-0094 was found on submerged decaying wood in a freshwater habitat in Thailand. Our study isolated this species for the first time on submerged decaying wood in Yunnan province, China.