Neostagonosporella bambusicola L.S. Dissan. & J.C. Kang, 2022

Dissanayake, Lakmali S., Marasinghe, Diana S., Thambugala, Kasun M. & Kang, Ji-Chuan, 2022, Neostagonosporella bambusicola sp. nov. (Phaeosphaeriaceae, Pleosporales) from bamboo in China, Phytotaxa 573 (2), pp. 262-274 : 265-267

Neostagonosporella bambusicola L.S. Dissan. & J.C. Kang sp. nov. ( FIGURE 2 )

Index Fungorum number: IF559874; Facesoffungi number: FoF09712

Etymology— Referring to the host “bamboo” from which the holotype was isolated.

Holotype — HKAS115852

Saprobic on dead leaves of bamboo ( Poaceae ). Sexual morph: Ascostromata 180–220 × 140–180 μm (x = 201 × 163 μm, n = 10), ellipsoidal, globose to subglobose or irregular in shape, semi-immersed in host epidermis, coriaceous, solitary to gregarious, multiloculate, erumpent through host tissue, with dark brown to black, glabrous, with a centrally located ostiole. Peridium 12–20 μm wide (x = 15 μm, n = 10), thin at base, thick at sides towards apex, upper part fused with host tissue, composed of two layers; outer layer: pale to brown pseudoparenchymatous cells of textura angularis, inner layer: hyaline, somewhat flattened cells of textura angularis. Hamathecium composed of 1–3 μm (x = 2 μm, n = 10) wide, cellular, septate pseudoparaphyses, embedded in a hyaline gelatinous matrix. Asci 70–130 × 13.5–15 μm (x = 92 × 13 μm, n = 20), 8-spored, bitunicate, fissitunicate, cylindrical to cylindric-clavate, short pedicellate (up to 10 μm), apically rounded with an ocular chamber. Ascospores 30–36 × 5.5–7.2 μm (x = 33 × 6 μm, n = 20), partially overlapping uni- to bi-seriate, hyaline, cylindrical to fusiform or cylindric-clavate, with acute ends, narrower towards end cells, straight or slightly curved, 5-7-septate, slightly constricted at septa, nearly equidistant between septa, guttulate, smooth-walled, surrounded by a 10–14 μm (x = 11 μm, n = 10) thick mucilaginous sheath. Asexual morph: Undetermined.

Culture characteristics— Colonies on PDA, reaching 2 cm diam., after 2 weeks at 20°C, medium dense, circular to slightly irregular with uneven margin, slightly raised and cottony surface, colony from above: white at the margin, pale-grey at the center. From below: yellowish margin, yellow to brown at the center; mycelium pale-grey.

Material examined— CHINA, Guizhou Province, Guiyang , Guizhou University , on dead leaves of bamboo, 28 May 2019, L. S . Dissanayake ( HKAS115852 , holotype), ex-type culture ( KUMCC 20-0031 ) .

Known distribution — Guizhou Province, China

Notes: Neostagonosporella bambusicola shares similar morphology with N. sichuanensis showing multiloculate ascostromata and cylindrical to fusiform, transversely multi-septate, straight or curved ascospores, which are widest at the central cells. In the present phylogenetic analyses, N. bambusicola clusters sister to N. sichuanensis with relatively high statistical support ( Figure 1 ). The two species are easily distinguishable since Neostagonosporella bambusicola has smaller ascomata (180–220 × 140–180 μm), cellular, septate pseudoparaphyses and ascospores with thick sheath (10–14 μm), whereas N. sichuanensis has large ascomata (1–2 mm × 230–340 μm), trabeculate pseudoparaphyses and ascospores with a thin sheath (5–9 μm).

Figures

FIGURE 1. RAxML tree based on a combined dataset of partial SSU_LSU_ tef 1-α _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. The new isolates are in bold red. The tree is rooted to Leptosphaeria doliolum (CBS 643.86) and Paraleptosphaeria dryadis (CBS 505.75). The scale bar represents the expected number of nucleotide substitutions per site.

FIGURE 2. Neostagonosporella bambusicola (HKAS115852). a, b. Appearance of ascostromata on host. c. Close up of ascostromata. d, e. Locule of ascostromata. f. Peridium. g. Pseudoparaphyses. h–j. Asci. k–n. Ascospores. o. Ascospores with mucilaginous sheath. p. Germinated ascospores. q, r. Colonies on PDA. (q-from above, r-from below). Scale bars: d, e = 50 μm, f, g = 5 μm, h–j = 50 μm, k–n= 10 μm, o–p = 20 μm.