Tubeufiales » Tubeufiaceae » Thaxteriellopsis

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 ( = 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 ( = 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 ( = 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)