Eutiarosporella dactylidis (K.M. Thambugala, E.Camporesi & K.D. Hyde) Dissanayake, Camporesi & K.D.Hyde, comb. nov.
Basionym: Tiarosporella dactylidis Thambugala, E.Camporesi & K.D. Hyde, Cryptog.Mycol.35: 359 – 367 (2014).
Index Fungorum number: IF 551751, Facesoffungi number: FoF 01650, Fig. 2
Saprobic on stem of grasses (Avenella sp.). Sexual morph Ascostromata 150 – 195 μm high × 175 – 240 μm diam., visible as black spots on host tissue, uniloculate, scattered or gregarious, globose to subglobose, ostiolate. Ostiole circular, central, papillate. Peridium up to 25 – 45 μm wide, comprising 2 layers: outer layer of thin, small, brown to dark brown cells of textura angularis, inner layer of thick, large, hyaline to lightly pigmented, cells of textura angularis. Hamathecium comprising 2 – 3 μm wide, hyphae-like, hyaline, sparse pseudoparaphyses. Asci 120 – 180 × 15 – 23μm (x̄ = 145 × 19 μm, n = 30), 8 – spored, bitunicate, fissitunicate, clavate to cylindric – clavate, pedicellate, apically rounded, with an ocular chamber. Ascospores 22 – 28 × 7 – 8.5 μm (x̄ = 25 × 8 μm, n = 30), uni to bi-seriate in the upper half, uniseriate at the base, hyaline, becoming olivaceous-brown at maturity, aseptate, ellipsoidal to fusiform, usually wider in the center, thick-walled, smooth – walled, surrounded by a mucilaginous sheath. Asexual morph see asexual morph description in Thambugala et al. (2014a).
Material examined: ITALY, Province of Forlì-Cesena [FC], Montebello – Modigliana, on dead stem of Avenella flexuosa L. (Poaceae), 24 November 2014, Erio Camporesi IT 2251 (MFLU 15–3502), living cultures MFLUCC 15–0915.
Notes: The genus Tiarosporella was introduced by Höhnel (1919) and is considered as an asexual genus in the family Botryosphaeriaceae. Thambugala et al. (2014a) introduced a sexual morph for the genus Tiarosporella; T. dactylidis Thambugala et al., based on the multi-gene phylogeny. Since the type species of Tiarosporella; T. paludosa (Sacc. & Fiori ex P. Syd.) Höhn clusters in a distinct clade in Botryosphaeriaceae apart from the species accommodated in Tiarosporella; Crous et al. (2015b) introduced a new genus Eutiarosporella to accommodate tiarosporella – like taxa, based on E. tritici (B. Sutton &Marasas) on Triticum aestivum L. from South Africa. The genus comprises three species, Eutiarosporella africana Jami et al., E. tricti and E. urbis-rosarum Jami et al. Based on the multigene phylogenetic analysis (Fig. 1), the ex-type strain of Tiarosporella dactylidis (MFLUCC 13–0276) clusters with other species in Eutiarosporella. With the species combined in Eutiarosporella here, the number of species in this genus increases to four.
Fig. 1 Phylogram generated from Maximum Parsimony analysis based on combined ITS and LSU sequence data of species of Botryosphaeriaceae. Parsimony bootstrap support values for MP ≥ 70 % are shown above the nodes and Bayesian posterior probabilities ≥95 % are indicated in bold branches. The tree is rooted.
Fig. 2 Eutiarosporella dactylidis sexual morph (MFLU 15–3502) a Appearance of ascostromata on host surface b Section through ascostroma c, d Immature asci e – g Mature bitunicate asci h, i Ascospores with inconspicuous mucilaginous sheath. Scale bars: b = 100 μm, c, d = 50 μm, e, f = 40 μm, g – i = 20 μm.