Novomicrothelia pandanicola S.N. Zhang & K.D. Hyde, 2017

Zhang, Sheng-Nan, Hyde, Kevin D., Jones, E. B. Gareth, Cheewangkoon, Ratchadawan, Boonmee, Saranyaphat, Doilom, Mingkwan, Mapook, Ausana & Liu, Jian-Kui, 2017, Novomicrothelia pandanicola sp. nov., a non-lichenized Trypetheliaceae species from Pandanus, Phytotaxa 321 (3), pp. 254-264 : 258-260

Novomicrothelia pandanicola S.N. Zhang & K.D. Hyde , sp. nov.

Index Fungorum number: IF 553176; Facesoffungi number: FoF 03289; Figure 2 .

Family: Trypetheliaceae

Etymology: Name reflects to the host Pandanus tectorius , from which the holotype was collected.

Holotype: MFLU 17-0753

Saprobic on the bark of Pandanus tectorius , with a tropical distribution. Sexual morph: Thallus ecorticate, non-lichenized, some part bordered by dark prothallus lines. Ascomata 490–990 μm diam., 190–200 μm high, solitary or irregularly confluent, immersed to erumpent, subglobose to flask-shaped, covered with black pseudoclypeus, in vertical section 183–305 μm diam., 177–248 μm high. Ostioles apical or rarely eccentric. Peridium 18–29 μm wide, with 5–6 layers of compressed cells of textura angularis, coriaceous, partly carbonaceous, dimidiate, comprising a mixture of host cells and brown fungal hyphae, K+ (olivaceous within 10% KOH solution). Hamathecium up to 1.5 μm wide, hyaline, filamentous, sparsely septate, branched and anastomosing pseudoparaphyses, embedded in a gelatinous matrix. Asci 75–137 × 12–20 μm, (x = 93.8 × 14.5 μm, n = 18), 8-spored, bitunicate, narrowly clavate to subcylindrical, pedicellate, occasionally constricted at the upper part, apically rounded, with a small ocular chamber, up to 1.5 μm high. Ascospores 16–32 × 5–10 μm (x = 24 × 7.3 μm, n = 30), hyaline, becoming brown with age, partly overlapping or biseriate, ellipsoid to obovoid or fusiform, verruculose, muriform and elongated, with 3–7 transverse septa, and 1–4 longitudinal septa in all cells and rarely in end cells, sometimes strongly constricted at the middle septum, straight or slightly curved, wall smooth, surrounded by an irregular, gelatinous sheath, observed more clearly when mounted in Indian ink. Asexual morph: Undetermined.

Culture characteristics:—Ascospores germinating on PDA within 48 hours at room temperature in natural light. Germ tubes produced from each end. Colonies growing well on both PDA and MEA media, and attaining a diameter of 1.5 cm on PDA after two months at room temperature, slow growing, obverse olive to grey-green or light grey-green, tufted colony center elevated, reverse dark green ( Figure 3 ). Mycelium 2–3 μm wide, hyaline to pale brown, aerial, septate, ornamented, branched and anastomosing. Chlamydospores 7.7–43 × 5−11.5 (x = 16.8 × 7.3 μm, n = 20), produced from mycelia, initially subglobose with 1 cell, hyaline, becoming 1–5 septate, pale brown to dark brown.

Material examined:— THAILAND, Chanthaburi, Ao Khung Kraben, on dead bark of Pandanus tectorius ( Pandanaceae R.Br. ), 7 July 2016, M. Doilom SN-T-04 (MFLU 17-0753, holotype); ex-type culture MFLUCC 16- 1382 = GZCC 17-0004. (HKAS 96378, isotype).

Figures

FIGURE 2. Novomicrothelia pandanicola (MFLU 17-0753, holotype). a–b Appearance of thallus and ascomata on host surface. c Close up ascoma on host surface. d Vertical section of ascoma. e–f Structure of peridium, f Peridium within 10% KOH solution. g Asci with paraphysoids. h–i Asci. j Trabeculate pseudoparaphyses. k Ascus apex with small ocular chamber.l–p Immature Ascospores, n Ascospore surrounded by an irregular gelatinous sheath in Indian ink, q Mature ascospore. Scale bars: b = 500 μm, c–d = 50 μm, e–f = 10 μm, g–i = 20 μm, j–q = 10 μm.

FIGURE 3. Novomicrothelia pandanicola on PDA. a Germinating ascospore. b–c Colony on PDA, above (b) and below (c). d Mycelium on PDA showing aerial hyphae. e–f Mycelium on MEA showing aerial hyphae. g–i Mycelium growing on PDA after two months, i Mycelium with a chlamydospore. Scale bars: a = 50 μm, d = 200 μm, e–f = 500 μm, g–i = 20 μm.