Deniquelata barringtoniae Ariyawansa & K.D. Hyde, Phytotaxa 105(1): 15 (2013)
Index Fungorum number: IF 800704; MycoBank number: MB 800704; Facesoffungi number: FoF 00035
Pathogenic on living leaves of Barringtonia asiatica. Sexual state: Ascomata 150–180 × 164–190 µm (x̄ = 175 × 167 µm, n = 10), immersed, scattered, globose to subglobose, black to dark brown, smooth-walled, with a papillate to depressed, elongate ostiole. Peridium 9–17 µm diam. (x̄ = 12 µm, n = 10), composed of 3–5 layers of brown to black, darkly pigmented, small, thick-walled, 2–5 µm wide cells of textura angularis, with the outer wall fused with the host cells, the inner wall consists of 2-layers of polygonal to rectangular, light brown- hyaline cells 1–4 μm diam. Hamathecium composed of dense, 1–3 µm diam. (x̄ = 2 µm, n = 20), broad, hyaline, septate pseudoparaphyses surrounding the numerous asci and embedded in a gelatinous matrix. Asci (-60) 68–80 × 10–15 µm (x̄ = 72 × 13 µm, n = 20), 8-spored, bitunicate, fissitunicate, clavate to broadly-clavate, with a 9–17 μm, short, broad, furcate, long pedicel, rounded at apex, with an ocular chamber. Ascospores 14–16 × 5–7 µm (x̄ = 15 × 6 µm, n = 40), biseriate or distichously arranged, partially overlapping, oblong to narrowly oblong, straight or somewhat curved, reddish-brown, with three transverse septa and 1–2 vertical septa in the central cells, constricted at the primary and secondary septa at maturity, verruculose, straight or slightly inequilateral, without a gelatinous sheath. Asexual state: unknown.
Material examined – THAILAND, Chiang Rai Province., Muang District, Bandu, Baan Khuakhae, on the leaf of Barringtonia asiatica(L.) Kurz (Lecythidaceae), 18 September 2011, K.D. Hyde (MFLU 12-0303, holotype).
Fig. 1 Deniquelata barringtoniae (MFLU 12-0303, holotype). a-b Fungus on host. c-d Section of ascoma (TS). e Section of peridium comprising a few layers of cells. f Hyaline pseudoparaphyses g-i Eight-spored asci with short, broad pedicel at the base. j Reddish-brown, muriform, ascospores. k Ascospores stained in Indian ink. l Germ tubes develop from ascospore cells. Scale bars: c-d = 100 µm, e = 5 µm, f = 5 µm, g-i = 20 µm, j-k = 10 µm, l = 20 µm.
Notes – Deniquelata is a monotypic genus characterized by immersed, dark brown to black ascomata, with bitunicate asci and brown, muriform ascospores. Deniquelata differs considerably from the type of Montagnula (M. infernalis) both in phylogeny and morphology (Ariyawansa et al. 2013c). Deniquelata is a pathogenic genus with fruiting bodies scattered in the necrotic host tissues. Ariyawansa et al. (2013c) concluded that phylogenetic analysis of the nucleotide sequences of combined 18S and 28S nrDNA provided good evidence that Deniquelata belongs to Montagnulaceae. In the present study, Deniquelata forms a distinct clade sister to Bimuria and Tremateia. Thus we accept this genus under Didymosphaeriaceae.