Acrocordiella yunnanensis L.S. Dissan, J.C. Kang & K.D. Hyde, 2021

Dissanayake, Lakmali S., Maharachchikumbura, Sajeewa S. N., Mortimer, Peter E., Hyde, Kevin D. & Kang, Ji-Chuan, 2021, Acrocordiella yunnanensis sp. nov. (Requienellaceae, Xylariales) from Yunnan, China, Phytotaxa 487 (2), pp. 103-113 : 107

Acrocordiella yunnanensis L.S. Dissan, J.C. Kang & K.D. Hyde , sp. nov. ( FIGURE 2 )

Index Fungorum Number : IF556940, Facesoffungi number: FoF 09458

Etymology:— referring to the location Yunnan Province where the fungus was collected.

Holotype:— HKAS111922

Saprobic on woody substrates of undetermined plants. Sexual morph: Appearing as black spots on the substrate with black margins, sometimes with circular sunken perforation through the bark. Ascomata 290–325 × 325–355 μm (x̅ = 307 × 336 μm, n = 10), immersed, solitary or in small groups within the bark, perithecial, globose to subglobose, black, ostiolate, papillate, periphysate. Papilla surrounded by a narrow darkened clypeus. Peridium 10–15 μm (x̅ = 12.5 μm) thick, comprising brown to hyaline, multi-layered, thick-walled cells of textura angularis. Paraphyses 3–5 μm (x̅ = 3.8 μm) wide, longer than asci, numerous, hardly septate, curved, hardly branched, trabeculae. Asci 100–160 × 30–40 μm (x̅ = 125 × 36 μm, n = 10), arising from basal and lateral cavity-surface of the ascoma, 8-spored, in the middle often biseriately arranged ascospores, bitunicate, fissitunicate, narrowly clavate to ovoid, or fusiform, with short, simple to knob-like pedicel, with thick-walled apex, inversely funnel-shaped dome (8–10 × 10–15 μm), staining pale yellow in Melzer’s solution. Ascospores 25–40 × 10–15 μm (x̅ = 34 × 12.5 μm), ellipsoid, narrowly rounded to nearly acute at the ends, multi-guttulate, 3–7 transversely septate, with 1 longitudinal septum, muriform, at first hyaline, greyish olive when young, becoming olivaceous to medium brown when mature, smooth and thick-walled with a mucilaginous sheath. Asexual morph: Undetermined.

Material examined:— CHINA, Yunnan Province, Xishuangbanna, Menghai County, Bulangshanxiang , 21.575908 N, 100.325724 E, 1063 m absl, on dead twigs of an unidentified dicotyledonous plant, 19 December 2018, D.N. Wanasinghe ( HKAS111922 , holotype); ibid. ( HKAS111923 , isotype) .

Known distribution:— Yunnan Province, China

Notes:—Phenotypic characterization reveals that our new species resembles Acrocordiella in its immersed ascomata with white or black margins and a peridium comprising brown to hyaline, thick-walled cells of textura angularis ( Hyde et al. 2020). In phylogenetic analyses ( Figure. 1 ), A. yunnanensis clusters to A. omanensis with relatively high bootstrap support (94% ML; 0.99% BYPP), but A. yunnanensis can easily be distinguished from A. omanensis . Acrocordiella omanensis has unitunicate, cylindrical asci with uniserriate 3-distoseptate ascospores without longitudinal septa, whereas A. yunnanensis has narrowly clavate to ovoid asci with biseriate, muriform ascospores with 3–7 distosepta with mucilaginous sheath. Furthermore, the ascomata dimensions of A. omanensis are larger than those of A. yunnanensis (x̅ = 780 × 720 μm vs 307 × 336 μm).

Figures

FIGURE 1. RAxML tree based on a combined dataset of partial LSU and ITS sequence analyses. Bootstrap support values for ML equal to or greater than 60 %, Bayesian posterior probabilities (BYPP) equal to or greater than 0.95 are shown as ML/ BYPP above the nodes. Type strains are in black bold and the new isolates are in red bold. The tree is rooted to Chaetosphaeria innumera (SMH2748). The scale bar represents the expected number of nucleotide substitutions per site.

FIGURE 2. Acrocordiella yunnanensis (HKAS111922, holotype). a, b. Ascomata on host substrate c. Transverse section of an ascoma. d, e. Vertical sections of ascomata.f. Peridium g. Ostiolar neck. h. Paraphyses. i–o.Asci (j. in Melzer’s solution). p–t.Ascospores (t. in Indian ink). Scale bars: e = 100 μm, g, i, j. = 20 μm, k–o. = 50 μm, h, p–s. = 10 μm, t–f. = 5 μm.