Byssosphaeria phoenicis Kular. & K.D. Hyde, 2022

Kularathnage, Nuwan D., Wanasinghe, Dhanushka N., Senanayake, Indunil C., Yang, Yunhui, Manawasinghe, Ishara S., Phillips, Alan J. L., Hyde, Kevin D., Dong, Wei & Song, Jiage, 2022, Microfungi associated with ornamental palms: Byssosphaeria phoenicis sp. nov. (Melanommataceae) and Pseudocoleophoma rhapidis sp. nov. (Dictyosporiaceae) from south China, Phytotaxa 568 (2), pp. 149-169 : 158

Byssosphaeria phoenicis Kular. & K.D. Hyde , sp. nov.

Index Fungorum number: IF559349; Facesoffungi number: FoF 10619, FIGURE 3

Etymology: referring to the host genus, Phoenix .

Saprobic on dead petioles of Phoenix roebelenii . Sexual morph: Ascomata 580–625 μm diam., 600–650 μm high (x̄ = 610 × 630 μm, n = 10), densely gregarious, superficial on subiculum, uniloculate, subglobose, black, coriaceous, setose, apapillate, ostiole wide, surrounding by a reddish orange disc, periphysate. Peridium 90–110 μm, 5–7-layered, comprises outer layer of black, thick-walled cells of textura angularis and 3–4-layered, hyaline, thick-walled cells of textura angularis. Setae 250–350 µm long, ends blunt, black, formed from the inner cell layer of peridium. Pseudoparaphyses 1–2 μm wide, hyaline, filamentous, trabeculate, aseptate, unbranched. Asci 100–160 × 10–15 (x̄ = 145 × 12 μm, n = 20), 8-spored, bitunicate, clavate, blunted at the apex without ocular chamber, long-stalked (50–70 μm long). Ascospores 25–30 × 5–7 µm (x̄ = 26 × 6 μm, n = 20), overlapping triseriate to 4-seriate, fusiform, slightly curved, smooth-walled, initially hyaline, pale brown to pale olivaceous at maturity, 1– (3)-septate, slightly constricted at the middle septum, surrounded by a thin, gelatinous sheath which swells around the septum and protrudes at both ends. Asexual morph: Undetermined.

Culture characters— Colonies on PDA reaching 2 cm diam., after one week at 20 °C in dark, colonies medium dense, circular to irregular, umbonate, curled, wooly, colony from above and reverse white to yellowish, mycelium white to yellowish with tufting; not producing pigments in PDA. Cultures do not sporulate within 30 days.

Material examined— China, Guangdong Province, Guangzhou City, Zhongkai University of Agriculture and Engineering (23°06’28.4”N 113°16’51.6”E), on dead petioles of Phoenix roebelenii (Arecaceae) , 8 June 2021, N.D. Kularathnage, NDK 29-1 ( ZHKU 21-0011 , holotype), ex-type living culture ZHKUCC 21-0122 ; ibid. NDK 29-2 ( ZHKU 21-0012 , isotype), ex-type living culture ZHKUCC 21-0123 .

Notes—The combined gene analysis of ITS, LSU, SSU and tef- 1 α ( FIGURE 1 ) showed that our Byssosphaeria isolates formed a distinct subclade that is sister to B. taiwanense (MFLUCC 17-2643) with ML/BI = 100/1.00 support. Comparison of the DNA sequence of ITS, LSU, SSU and tef- 1 α locus of Byssosphaeria phoenicis , with B. taiwanense revealed the base pair differences of 14/505, 6/873, 10/1000 and 10/943 respectively. However, our species is different from Byssosphaeria taiwanense in having ascomata with thick peridium at the sides (90–110 μm) and overlapping triseriate to 4-seriate ascospores in the ascus. The matured ascospores are 3-septate and brick red to brown. The mucilaginous sheath swells widely (5–8 µm) around the central septum and narrowly protrudes towards the ends of the ascospores. Byssosphaeria taiwanense has ascomata with thin peridium at sides (35–50 μm), pale brown to olivaceous brown, 1-septate ascospores when mature with an overlapping uniseriate to overlapping biseriate ascospore arrangement. The mucilaginous sheath swells uniformly around the ascospores (10–12 µm) ( Tennakoon et al. 2018).

Byssosphaeria alnea , B. diffusa , B. erumpens , B. hainanensis , B. jamaicana , B. musae , B. oviformis , B. rhodomphala , and B. schiedermayeriana have been collected from China ( Barr 1984, 1990, Chen & Hsieh 2004, Li & Zhuang 2008, Liu et al. 2015, Tennakoon et al. 2018). Our species is morphologically distinct from all Byssosphaeria species and a morphological comparison of Byssosphaeria species is provided in TABLE 3 .

Figures

FIGURE 1. Phylogram generated from maximum likelihood analysis based on combined ITS, LSU, SSU, and tef-1α sequence alignment. Maximum likelihood bootstrap support values greater than 60% and Bayesian posterior probabilities greater than 0.95 are given at the nodes. The tree is rooted with Hysterium angustatum (MFLU 16-1179). Ex-type cultures are in bold and the newly generated sequences are indicated in red bold

FIGURE 3. Byssosphaeria phoenicis (ZHKU 21-0012, holotype). a Habitat.b–d Ascomata on substrate. e Vertical section of an ascoma. f Setae. g Peridium. h Pseudoparaphyses. i, j Asci. k–m Ascospores. n An ascospore in Indian Ink to show a sheath. o Colony on PDA (above view). p Colony on PDA (reverse view). Scale bars: c, d = 1 mm, e = 300 μm, f, g = 100 μm, h = 10 μm, i, j = 40 μm, k–n = 15 μm.