Tubeufia guangxiensis Chaiwan, Boonmee, Y.Z. Lu & Hyde
Index Fungorum number: IF553873; Faces of fungi number: FoF03779
Holotype: GZAAS 16–0057
Etymology: refers to the location where the fungus was collected, Guangxi, China.
Saprobic on submerged decaying wood. Sexual morph: Ascomata 255–300 μm diam. × 140–160 μm high (x̄ = 275 × 150 μm, n = 5), superficial, subglobose, spherical to clavateobovate oval to ellipsoid, narrow at apex, solitary, scattered, pale to yellowish. Peridium 25–29 μm wide, composed of several layers of white light brown cells of textura angularis. Hamathecium comprising numerous filiform, septate, hyaline, pseudoparaphyses. Asci 160–230 × 12–17 μm (x̄ = 197 × 14.5 μm, n = 20), 8-spored, bitunicate, cylindrical, rounded at apex, long pedicellate. Ascospores 135–155 × 3–5 μm (x = 143 × 4 μm, n = 20), fasciculate, spiral, broadly elongate, cylindrical to sub-fusiform, slightly curved, tapering towards rounded ends, phragmosporous, 12–15-septate, guttulate, hyaline, smooth-walled. Asexual morph: hyphomycetous, helicosporous. Conidiophores 24–39 × 3.5–5 μm (x̄ = 32 × 4.5 μm,
n = 10), mononematous, erect, short, septate, pale brown, smooth-walled. Conidiogenous cells 10–17 × 3.5–5 μm (x̄ = 13 × 4.5 μm, n = 10), monoblastic, holoblastic, integrated, terminal, cylindrical, each with single conidium. Conidia 45–70 × 6.5–9 μm (x̄ = 60 × 7.5 μm, n = 20) with 360–460 μm long, coiled 1½–2½ times when tight, becoming loosely coiled in water, rounded at apical end, up to 50-septate, slightly constricted at septa, hyaline, guttulate, smooth-walled. (Chaiwan et al. 2017)
Culture characteristics: Ascospores germinating on water agar and producing germ tubes within 12 hours. Colonies growing on PDA, circular, with flat surface, edge entire, reaching 11 mm in 2 weeks at 28 °C, pale brown to brown, mycelium superficial and partially immersed, branched, septate, hyaline to pale brown, smooth.
Material examined: CHINA, Guangxi Province, Fang Cheng Gang City, on submerged decaying wood in a freshwater stream, 15 May 2016, Y.Z. Lu, JHC14–2 (GZAAS 16–0057, holotype), ex-type living culture, MFLUCC 17–0045 = GZCC 16–0045; ibid, JHC01–3 (GZAAS 16–0042, paratype), ex-type living culture, MFLUCC 17–0038 = GZCC 16–0030; ibid. JHC10 (GZAAS 16–0053, paratype), ex-type living culture, GZCC 16–0041; Ibid., JHC21–5 (GZAAS 16–0066, paratype), ex-type living culture, GZCC 16–0054; ibid, JHC25-1 (GZAAS 16–0103, paratype), ex-type living culture, GZCC 16–0091; ibid., JHC26–2 (GZAAS 16–0102, paratype), ex-type living culture, GZCC 16–0090.
Notes: Tubeufia guangxiensis is a new species found in freshwater habitat in China. Morphologically it resembles the type species, T. javanica in having oval, pale to yellowish ascomata with thin-walled, long cylindrical asci and ascospores. Phylogenetically, T. guangxiensis forms a sister clade to T. roseus, T. cylindrothecia, T. mackeniei and T. lilliputeus with strong statistical support (100% and 97% BS and 1.00 PP). Tubeufia guangxiensis differs from these species by having asexual morph found on submerged decaying wood in a freshwater stream (Boonmee et al. 2014, Luo et al. 2017). The asexual morph of T. guangxiensis found on submerged decaying wood in freshwater habitat is helicosporous and appears similar to T. hyalospora and T. roseohelicospora but differs by smaller mononematous conidiophores and coiled conidia. Tubeufia javanica has no asexaul morph reported. (Chaiwan et al. 2017)
Freshwater distribution: China (Chaiwan et al. 2017; Lu et al. 2018)