Diplodia galiicola Dissanayake, Camporesi & K.D.Hyde.
Index Fungorum number: IF551315; Facesoffungi number: FoF00884; Fig. 2
Etymology: Referring to the host Galium sp.
Holotype: MFLU 15-1310
Saprobic on stem of Galium sp. Sexual morph: Undetermined. Asexual morph: Conidiomata 320 – 385 μm high × 425 – 490 μm diam. (x̄ = 350 × 470 μm, n = 10), stromatic, solitary, immersed in the host, dark brown to black, slightly depressed, uniloculate, globose to subglobose, ostiole central, apapillate. Peridium 25 – 35 μm wide, outer layer composed of dark brown cells of textura angularis, inner layers of thin-walled hyaline cells of textura angularis. Conidiogenous cells 8 – 15μm high × 5 – 7 μm wide, hyaline, thin – walled, smooth, cylindrical, swollen at the base, discrete, producing a single conidium at the apex. Conidia 17 – 23 × 11 – 13 μm (x̄ = 20 × 12 μm, n = 50), initially hyaline, becoming dark brown, moderately thick – walled, wall externally smooth, roughened on the inner surface, aseptate, ovoid, widest in the center, apex obtuse, base truncate or rounded.
Cultural characteristics – Conidia germinating on WA within 24 h and germ tubes produced from lower end. Colonies growing on PDA, covering the entire plate in 1 week at 28 °C, developing dense aerial mycelium with age, become pale olivaceous-grey to olivaceous black at the surface, and olivaceous black from below.
Material examined – ITALY, Province of Forlì-Cesena [FC], Strada San Zeno, Galeata, on dead stem of Galium sp. (Rubiaceae), 30 October 2013, E. Camporesi, IT 1495 (MFLU 15-1310, holotype), ex-type living cultures, MFLUCC 15–0647, KUMCC15-0074, CFTCC 15-0001.
Notes – In the combined phylogenetic analysis (ITS, EF1-α and β-tubulin genes), Diplodia galiicola is phylogenetically most closely related to D. seriata with high bootstrap support (1.0 Bayesian posterior probability) (Fig. 1). The conidia of D. galiicola differ from D. seriata in being shorter. The average conidia of D. seriata are longer than or equal to 25 μm (Phillips et al. 2013), while the conidia of D. galiicola are never 25 μm long (Fig. 2).
Fig. 1 Phylogram generated from RAxML based on combined ITS, EF and β-tubulin sequenced data for Diplodia species. Maximum likelihood bootstrap support values and Bayesian posterior probabilities greater than 50 % and 0.90 are indicated above the nodes. Only ex-type and voucher strains are used and the new isolates are in blue. The tree is rooted with Endomelanconiopsis endophytica CBS 120397.
Fig. 2 Diplodia galiicola (holotype) a, b Conidiomata on host substrate c Cross section of conidioma d Mature and immature conidia with conidiogenous cells e Immature conidia attached to conidiogenous cells f Mature conidia attached to conidiogenous cells g, h Mature and immature conidia i, j Immature conidia k, l Mature conidia. Scale bars: c = 200 μm, d – l = 20 μm.