Thaxteriellopsis lignicola
Thaxteriellopsis lignicola Sivan., Panwar & S.J. Kaur
Index Fungorum number: IF 324512; Facesoffungi number: FoF 01866
Holotype: IMI 197065
Saprobic on submerged decaying wood in a freshwater stream. Sexual morph: Ascomata 235–320 μm high, 280–345 μm wide, superficial, solitary and scattered, globose to subglobose, shiny, dark brown to black, obviously collapsed when dry, setose, coriaceous. Setae 110–230 μm long, covering the whole ascomata, brown to dark brown, septate, unbranched, apically rounded, thick-walled. Peridium 23–34 μm thick, multi-layered, outer layer comprising pale brown to dark brown cells of textura angularis, inner layer comprising hyaline to pale brown cells of textura angularis. Hamathecium comprising numerous, 1.5–3 μm wide, filiform pseudoparaphyses. Asci 110–185 μm long, 15–19 μm wide (x̄ = 141 × 17 μm, n = 20), 8-spored, bitunicate, cylindrical to clavate, apically rounded, with a 30–55 μm long pedicel. Ascospores 24–40 μm long, 6.5–7.5 μm wide (x̄ = 34 × 7 μm, n = 50), 2–3- seriate, clavate to fusiform, upper part broad, slightly curved, ends rounded, 5-septate, hyaline, smooth-walled. Asexual morph: Hyphomycetous, helicosporous. Conidiophores micronematous, mononematous, erect, cylindrical, arising as lateral branches from creeping hyphae, branched or unbranched, septate, slightly constricted at septa so as to give a monilioid appearance, 20–95 μm long, 6–7 μm wide, the lower part brown and the upper part pale brown, smooth-walled. Conidiogenous cells holoblastic, mono- to polyblastic, integrated, sympodial, terminal, cylindrical, 9– 11 μm long, 5.5–7 μm wide, pale brown, smooth-walled. Conidia solitary, acropleurogenous, helicoid, solitary, 12– 18 μm diam. and conidial filament 5–7 μm wide in the broadest part (x̄ = 14 × 6 μm, n = 20), tapering to 2.5–3 μm wide near apex and base, 35–45 μm long, tightly coiled 1.25–1.5 times, not becoming loose in water, rounded at tip, 6-septate, guttulate, hyaline, smooth-walled. (Description from Lu et al. 2018)
Material examined: THAILAND, Chiang Rai, Muang, Ban Nang Lae Nai, on decaying wood in a freshwater stream, 28 November 2015, Saranyaphat Boonmee and Yong-Zhong Lu, TUB04 (MFLU 17–1166 = HKAS 100722), living culture, MFLUCC 16–0024; Ibid., TUB05–2 (MFLU 17–1168), living culture, MFLUCC 16–0026.
Notes: Our two new collections of Thaxteriellopsis lignicola are morphologically different from other previously described specimens. The ascomata of our new collections are obviously collapsed when dried and larger sized than others. Its setae and asci are longer than those of previously described records (Boonmee et al. 2011, 2014). The asexual morph was found from the cultures. Its conidia are typical helicoma-like but conidiophores are distinct. Phylogenetically, our two new isolates and other five known isolates formed one clade and the phylogenetic result shows some slight divergence between them. However, they should be the same species. We compare our isolates to the type strain of T. lignicola and there are 1 bp, 6 bp, 2 bp differences in their ITS, RPB2 and TEF1a sequence data respectively, which may explain their slight phylogenetic divergence. However, we could not identify any morphological features to separate our two isolates and those fewer gene base pair changes are not enough to indicate they are different species, and thus, we identify our two new isolates as T. lignicola. (Notes from Lu et al. 2018)
Freshwater distribution: Thailand (Lu et al. 2018)
Fig. 1. Thaxteriellopsis lignicola (MFLU 17–1168). a, b Superficial ascomata on substrate. Note ascomata surrounded by brown to black setae. c Ascoma. d Peridium. e Seta. f Asci with hamathecium. g–i Asci. j–m Ascospores. Scale bars: a, b = 500 μm, c = 200 μm, d, j–m = 20 μm, e–i = 50 μm. (Lu et al. 2018)
Fig. 2. The asexual morph of Thaxteriellopsis lignicola (from sexual morph’s cultures). a Germinating ascospore. b, c Colonies on PDA from above and below. c Colony on PDA from above. e, h, i Conidiophores with attached conidia. f, g Conidiophores. j–o Conidia. Scale bars: a, i–o = 10 lm, d = 200 μm, e = 50 μm, f–h = 20 μm. (Lu et al. 2018)
References
Boonmee S, Zhang Y, Chomnunti P, Chukeatirote E, Tsui CKM, Bahkali AH, Hyde KD (2011) Revision of lignicolous Tubeufiaceae based on morphological reexamination and phylogenetic analysis. Fungal Divers 51:63–102. https://doi.org/10.1007/s13225-011-0147-4
Boonmee S, Rossman AY, Liu JK, Li WJ, Dai DQ, Bhat JD, Jones EBG, McKenzie EHC, Xu JC, Hyde KD (2014) Tubeufiales, ord. nov., integrating sexual and asexual generic names. Fungal Divers 68:239–298 . https://doi.org/10.1007/s13225-014-0304-7
Lu YZ, Liu JK (Jack), Hyde KD, Jeewon R, Kang JC, Fan C, Boonmee S, Bhat DJ, Luo ZL, Lin CG, Eungwanichayapant PD (2018) A taxonomic reassessment of Tubeufiales based on multi-locus phylogeny and morphology. Fungal Divers 92:131–344. https://doi.org/10.1007/s13225-018-0411-y
Recent Genus
1Neochlamydotubeufia
Neohelicomyces
Recent Species
Neohelicomyces submersusNeohelicomyces hyalosporus
Neohelicomyces grandisporus