Neodeightonia rattanica
Neodeightonia rattanica Konta & K.D. Hyde, sp. nov.
Index Fungorum number: IF552168; Facesoffungi number: FoF 02237 Etymology: The specific epithet refers to the common name for the host, rattan. Holotype: MFLU: 15-1443
Figs 2–3
Saprobic on rachis of Calamus sp. Sexual morph: Ascomata 222–241 high × 246–278 μm diam. × 235 μm, n = 10), immersed, solitary, scattered, uniloculate, subglobose, brown to reddish brown, with a long neck, rounded at the base. Ostiole central non-papillate. Peridium 49–76 μm dia μm, n = 10), relatively thick, comprising several layers, outer layer thick, comprising reddish brown-walled cells of textura angularis, inner layer thin, comprising hyaline cells of textura angularis. Hamathecium comprising hypha-like, hyaline, septate, cellular pseudoparaphyses, up to 2.7 μm wide, often constricted at the septa. Asci 113–141 × 19–25 μm （av. = 138 × 22 μm, n = 10), 8-spored, bitunicate, fissitunicate, cylindrical-clavate, with a thick endotunica, long pedicellate, apically thickened, with a distinct, ocular chamber. Ascospores 22–25 × 8–11 μm μm, n = 20), overlapping biseriate or obliquely biseriate, hyaline, ellipsoidal-fusiform, aseptate, often with a large guttule at the centre when immature, becoming granulate, with terminal apiculi, smooth-walled, surrounded by thick mucilaginous sheath. Asexual morph: Coelomycetous. Conidiomata stromatic 245–349 high × 208–305 μm diam. (av. = 297 × 255 μm, n = 5)pycnidial, superficial, purplish to black, covered with dense mycelium, on PDA uni-to multilocular, individual or aggregated. Paraphyses cylindrical, aseptate, hyaline. Conidiogenous cells 6–11 × 2–3 μm (av. = 9.7 × 2.7 μm, n = 10), holoblastic, cylindrical to subcylindrical, hyaline. Conidia 19–22 × 7–9 μm(av. = 20.7 × 8.4 μm, n = 20), initially hyaline, pale to dark brown when mature, unicellular, ellipsoid to obovoid, thick-walled, with granular content, rounded at the apex.
Culture characters – Ascospores germinating on MEA within 24 hours and germ tubes produced from both ends. Colonies on MEA fast growing, after 2 weeks reaching 7–8.5 cm diam. at 25°C, white at the edge, grey in the middle, outwardly strongly radiating. After 5 months of incubation, the colonies on MEA, becoming grey-olivaceous and spongy, hyphae, septate, branched and smooth, form asexual morph after 2 months.
Material examined – THAILAND, Phang-Nga, on dead rachis of Calamus sp. (Arecaceae), 6 December 2014, S. Konta, DNH05e (MFLU 15-1443, holotype; MFLU 15-0288, HKAS92531, HKAS92529, isotype); ex-type living culture, MFLUCC 15-0712, MFLUCC 15-0313.
Notes – Neodeightonia rattanica is characterized by large ascomata and ellipsoidal- fusiform, granulate ascospores, often with a single large guttule in immature ascospores, with polar apiculi and a thick mucilaginous sheath. Multi-locus analyses showed that N. rattanica (strain MFLUCC 15-0712) is closely related to N. rattanicola (strain MFLUCC 15-0319), but forms a distinct lineage (Fig. 1). Morphologically, Neodeightonia rattanica differs from N. rattanicola in having larger ascomata with a reddish brown peridium, while in N. rattanicola the peridium is dark brown to black (Figs. 2 vs Fig. 4, Table 2). The conidiomata of N. rattanica produced on media are purplish to black, while in N. rattanicola conidiomata on media are larger and dark brown to reddish brown (Figs. 3 vs Fig. 5, Table 3). Neodeightonia rattanica differs from N. subglobosa (the type species) in having hyaline, aseptate, granulate ascospores, often with a single large guttule in immature ascospores, while N. subglobosa has brown, 1-septate ascospores. Neodeightonia rattanica has ellipsoidal-fusiform ascospores with polar apiculi, while N. microspora has obovoid ascospores without polar apiculi (Figs 2 viz Fig 2 f–j Dai et al. (2016), Table 2). Although it is similar to N. palmicola in the sexual morph they differ in the asexual morph with aseptate conidia while conidia of N. palmicola have a single septum.
Fig. 2 – Neodeightonia rattanica (holotype) a. Appearance of ascomata on host substrate. b, c. Close-up of ascomata. d. Section of ascoma. e. Peridium. f. Pseudoparaphyses. g–k. Immature to mature asci. j, m. Ascospores with a single large guttule. l–q. Ascospores with polar apiculi and mucous sheath. r. Culture on MEA after 1. month, front and reverse. Scale bars: a = 500 μm, b–c = 200 μm, d = 50 μm, e = 20 μm, f = 10 μm, g–k = 20 μm, l–q = 10 μm.
Fig. 3 – Neodeightonia rattanica (from ex-type culture) a. Section of conidioma. b. Peridium. c–k. Conidiogenous cells with conidia. l−o. Immature conidia. p–q. Mature conidia. Scale bars: a = 50 μm, b–q = 10 μm.