Tubeufia sympodilaxispora Y.Z. Lu, J.C. Kang & K.D. Hyde
Index Fungorum number: IF 554910; Facesoffungi number: FoF 04765
Etymology: “sympodi-” referring to sympodial conidiogenous cells of this fungus; “laxispora” referring to loosely helicoid conidia.
Holotype: HKAS 97430
Saprobic on decaying wood in a freshwater stream. Sexual morph: Undetermined. Asexual morph: Hyphomycetous, helicosporous. Colonies on the substratum superficial, effuse, gregarious, white to pale brown. Mycelium composed of partly immersed, partly superficial, hyaline to pale brown, septate, abundantly branched hyphae, with masses of crowded, glistening conidia. Conidiophores macronematous, mononematous, flexuous, cylindrical, branched, septate, 25–45 μm long, 3–5 μm wide, hyaline to pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, intercalary or terminal, cylindrical, repeatedly geniculate, truncate at apex after conidial secession, 9–17 μm long, 3–5 μm wide, hyaline to pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, rounded at tip, 45–70 μm diam. and conidial filament 5–8 μm wide (x̄ = 60 × 6.5 μm, n = 20), 270–455 μm long, loosely coiled 1¼–1¾ times, becoming loosely coiled or fully uncoiled in water, indistinctly multi-septate, guttulate, hyaline, smooth-walled. (Lu et al. 2018)
Culture characteristics: Conidia germinating on water agar and germ tubes produced from conidia within 24 h. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 21 mm in 3 weeks at 28 °C, pale brown to brown in PDA medium. Mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.
Material examined: CHINA, Guangxi Province, Fangchenggang City, on submerged decaying wood in a freshwater stream, 15 May 2016, Yong-Zhong Lu, JHC21–2 (HKAS 97430, holotype; GZAAS 16–0064, isotype), ex-type living culture, MFLUCC 17–0048, GZCC 16–0052; Ibid., JHC 24 (GZAAS 16–0070, paratype), living culture, GZCC 16–0058.
Notes: Morphologically, Tubeufia sympodilaxispora is similar to T. sympodihylospora in conidiogenous cells and conidia but can be recognized by its shorter and narrower conidiophores (25–45 × 3–5 μm vs. 40–90 × 5–7 μm). Our two newly obtained isolates clustered together with two unidentified Tubeufia strains (Tubeufia sp. BCC 3580 and Tubeufia sp. MLTS 119). We could not compare their morphology because the latter two lack morphological information (Kodsueb et al. 2006), but our phylogenetic result indicates that they are the same species. We compare sequence data and found that there are only two noticeable nucleotide differences in LSU between the ex-type strain MFLUCC 17–0048 and Tubeufia sp. BCC 3580, and no difference between MFLUCC 17–0048 and Tubeufia sp. MLTS 119 (both BCC 3580 and MLTS 119 have only LSU sequence data), which also indicate that they are conspecific. Therefore, we introduce these four isolates as Tubeufia sympodilaxispora sp. nov. (Lu et al. 2018)
Freshwater distribution: China (Lu et al. 2018)