Equiseticola fusispora K Abdelsalam, Tibpromma, Wanasinghe & K.D. Hyde, 2016

Abd-Elsalam, Kamel A., Tibpromma, Saowaluck, Wanasinghe, Dhanushka N., Camporesi, Erio & Hyde, Kevin D., 2016, Equiseticola gen. nov. (Phaeosphaeriaceae), from Equisetum sp. in Italy, Phytotaxa 284 (3), pp. 169-180 : 173-174

Equiseticola fusispora K Abdelsalam, Tibpromma, Wanasinghe & K.D. Hyde , sp. nov.

Index Fungorum number: IF 551563; Facesoffungi number: FoF 01242; Fig. 2

Etymology:—The specific epithet fusispora refers to fusoid ascospores.

Saprobic on decaying stem of Equisetum sp. ( Equisetaceae ). Sexual morph: Ascomata 230–250 μm high, 200– 215 μm diam. (x = 239 × 208 μm, n = 5), scattered, solitary, immersed to semi-immersed, uniloculate, ovoid, ostiolate.

Ostiole central with minute papilla. Peridium 10–18 μm wide, composed of 3–6 layers, of brown to dark brown cells,

arranged in a textura angularis. Hamathecium of dense, 1–2 μm wide, filamentous, septate cellular, pseudoparaphyses, anastomosing above the asci. Asci 55–90 × 4–9 μm (x = 70 × 8 μm, n = 20), 8-spored, bitunicate, fissitunicate,

cylindrical, with long acute or knob-like pedicel, apically rounded, with well-developed ocular chamber. Ascospores 16–20 × 3–5 μm (x = 17 × 4 μm, n = 20), overlapping 1–2-seriate, initially hyaline, becoming yellowish pale brown at maturity, fusiform with rounded ends, 4–5-septate, usually 5-septate, distinctly septate, with distinct guttules in each cell, not constricted at the septa, smooth-walled, without mucilaginous sheath. Asexual morph: Undetermined.

Culture characteristics:—Colonies on MEA reaching 2.5 cm diam. in 2 weeks at 16 °C, white to grey in the center, with circular edge, reverse grey to dark grey, flat on the surface, without aerial mycelium. Hyphae septate branched, hyaline, thin.

Material examined:— ITALY, Province of Forli-Cesena, Strada San Zeno, on Equisetum sp. , 5 February 2014,

Erio Camporesi, IT 1701 ( MFLU 14-0702 , holotype; HKAS94574 , isotype) ; ex-type living culture, MFLUCC 14 -

0522.

Notes:—Our collection of Equiseticola fusispora , is related to Ophiosphaerella agrostidis ( MFLUCC 11-0152 & MFLUCC 12-0007) and O. aquatica ( MFLUCC 11-0033) in Phaeosphaeriaceae with high support (99% ML, 96% MP and 1.00 BYPP). Ophiosphaerella and Equiseticola are morphologically distinct, Equiseticola has a thin peridium, long acute or knob-like pedicel, with well-developed ocular chamber and fusiform, 5-septate ascospores, whereas Ophiosphaerella has a thick peridium, short pedicellate asci, with an indistinct ocular chamber and fasciculate multi-septate ascospores. Phaeosphaeria arenaria , P. epicalamia , P. huronensis , P. luctuosa , P. nofolcia , P. recessa and P. saronica also have 5-septate, fusiform ascospores ( Shoemaker & Babcock 1984), that are similar to Equiseticola fusispora , but their relationship cannot be verified as no sequence data are available for comparison. Equiseticola is morphologically resembles with Nodulosphaeria in ascomata characters, peridium structures, cylindrical to cylindric-clavate asci and fusiform ascospores. However Nodulosphaeria is different from Equiseticola in having external or internal periphyses-like setae in ostiole, a swollen upper cell in ascospores with terminal appendages, while Equiseticola has an ostiole without setae, and ascospores without swollen cells or terminal appendages. Thus we introduce a new genus Equiseticola to accommodate our taxon based on unique morphological characteristics together with phylogenetic data.

Sequence analyses of rDNA resulted in 13.68 % of parsimony-informative characters (quite low) and therefore it is advisable to consider or evaluate the utility of several other protein genes such as DNA-directed ribosomal polymerase II ( RPB 2) or translation elongation factor alpha 1 (tef1) to investigate phylogeny among this group of fungi.

Figures

FIGURE 2. Equiseticola fusispora (MFLU 14-0702, holotype) a Appearance of fungus on host surface. b Cross section of ascoma. c Close up of ostiole. d Section of peridium. e Pseudoparaphyses. f–g Asci. h Ocular chamber. i–o Ascospores. p Germinating ascospore. Scale bars: a = 200 μm, b = 50 μm, c = 20 μm, d, h–p = 5 μm, e = 2 μm, f–g = 20 μm.