Corylicola italica Wijesinghe, Camporesi, Yong Wang bis & K.D. Hyde 2020, sp. nov.
MycoBank number: MB 557768; Index Fungorum number: IF 557768; Facesoffungi number: FoF 08685;
Holotype: scientificName: Corylicola italica Wijesinghe, Camporesi, Yong Wang bis & K.D. Hyde 2020; phylum: Ascomycota; class: Dothideomycetes; order: Pleosporales; family: Bambusicolaceae; genus: Corylicola; stateProvince: Province of Forlì-Cesena; county: Italy; locality: near Meldola; year: 2019; month: March; habitat: Terrestrial; fieldNotes: on a dead hanging branch of Corylus avellana (Betulaceae); recordedBy: Erio Camporesi; identifiedBy: S.N. Wijesinghe; dateIdentified: 2019; collectionID: MFLU 19–0500; collectionCode: IT4211
Other material: scientificName: Corylicola italica; type: ex-type living culture; occurrenceID: MFLUCC 20– 0111
Saprobic on a dead, hanging branch of Corylus avellana L. Sexual morph: (Fig. 2), Ascomata 210–300 high, 200–260 µm diam. (x̄ = 261 × 227 µm), solitary, scattered, immersed, erumpent at maturity, raised as dark spots on the substrate, sessile, globose to subglobose, coriaceous, uni-loculate with an ostiole. Ostiole 50–65 µm long, 30–35 µm wide, central, papillate, lined with hyaline periphyses. Peridium composed of two layers, unequally thickened, 15–30 µm wide at the apex and 10–25 µm wide at the base, outermost layer comprising blackish to dark brown cells of textura angularis fused with host tissues, inner layer comprising hyaline cells of textura prismatica.
Hamathecium comprising numerous pseudoparaphyses, which are 1–2 µm wide (x̄ = 2 µm, n =10), dense, filamentous, cellular, with distinct septa, not constricted at the septa, branching and anastomosing above the asci. Asci 55–65 × 6–8 µm (x̄ = 61 × 7 µm, n =20), 8-spored, bitunicate, fissitunicate, cylindrical, short distinct pedicel with furcate ends, apically rounded, well-developed ocular chamber. Ascospores 10–15 × 3–4 µm (x̄ = 12 × 3.5 µm, n =40), overlapping, uni-seriate, fusiform to ellipsoidal, straight, yellowish when young, becoming pale brown at maturity, single-septate, constricted at the septum, rounded at the apices, upper cell is wider than the lower cell (2–5 vs. 2–4 µm (x̄ = 4 vs. 3.25 µm, n =40), echinulate, guttulate. Asexual morph: (Fig. 3), Coelomycetous forming naturally on PDA media after 12 weeks. Conidiomata 175–200 high 150–170 µm diam. (x̄ = 183 × 161 µm) pycnidial, solitary to gregarious, scattered, semi-immersed to superficial, visible as black spore mass surrounded by cellular vegetative hyphae (1–2 µm width), globose to subglobose, glabrous, uni- loculate to multi-loculate, ostiolate. Ostiolate 45–50 µm long, 50–60 µm wide, central and circular. Conidiomata wall 7–20 µm wide, composed of several layers of pale to dark brown, pseudoparenchymatous cells, outermost layers comprising 3−5 layers of dark brown cells of textura prismatica to textura angularis, inner layers comprising 2−3 layers of pale brown to hyaline cells of textura angularis. Conidiophores reduced to conidiogenous cells, originated from the basal cavity of conidiomata. Conidiogenous cells 3–4.5 × 2–4 μm (x̄ = 3.6 × 3 μm, n = 30), holoblastic, phialidic, ampulliform, yellowish to pale brown, aseptate, smooth-walled. Conidia 3–5 × 2–3 μm (x̄ = 4 × 2.5 μm, n = 30), solitary, globose or oblong to ellipsoid, rounded or obtuse ends, yellowish to pale brown, aseptate, rarely guttulated, one-celled, smooth-walled.
Culture characteristics: Ascospores germinating on PDA within 24 hours from single- spore isolation. Colonies on PDA reaching 5–10 mm diam. after 14 days at 16°C, circular, crenated edge, flat with dense, whitish-grey in upper and brownish-black in the lower surface of the colony. Sporulated after 12 weeks.
Referring to the country where the holotype was collected, Italy
Corylicola italica sp. nov. shows morphological characters that are similar to other representatives in the family Bambusicolaceae. Based on morphological comparison with the type species of other genera in the family, Corylicola italica is similar to Palmiascoma gregariascomum (MFLU 11–0211) in having uni-loculate ascomata, central ostioles with minute papilla, cellular pseudoparaphyses and single-septate, echinulate, brown ascospores (Liu et al. 2015). Corylicola italica has cylindrical asci with short, furcate pedicels similar to Bambusicola massarinia (MFLU 12–0405), while P. gregariascomum has clavate asci with short rounded to obtuse pedicels (Dai et al. 2012, Liu et al. 2015). The branching and anastomosing pseudoparaphyses above the asci of C. italica are similar to B. massarinia and P. gregariascomum. However, the absence of a mucilaginous sheath around the ascospores in C. italica distinguishes it from both B. massarinia and P. gregariascomum (Dai et al. 2012, Liu et al. 2015). In addition, B. massarinia has hyaline ascospores, whereas both C. italica and P. gregariascomum have yellowish-brown ascospores (Dai et al. 2012, Liu et al. 2015).
The asexual state of C. italica (Fig. 3) is similar to P. gregariascomum (MFLUCC 11– 0175) and Leucaenicola aseptata (MFLUCC 17–2423) in having pycnidial, globose to subglobose and glabrous conidiomata with a central ostiole and similar structures of conidiomata walls (outer layers; textura angularis to textura prismatica, inner layers; textura angularis) (Liu et al. 2015, Jayasiri et al. 2019). However, C. italica differs from these species in having globose conidia that are rarely guttulate, rather than oblong or ellipsoidal (Liu et al. 2015, Jayasiri et al. 2019). Bambusicola massarinia (MFLUCC 11– 0389) is different from C. italica in having cylindrical conidia. Leucaenicola aseptata (MFLU 17–2423) distinguishes itself, based on its enteroblastic conidiogenous cells (Dai et al. 2012, Jayasiri et al. 2019). Corylicola italica and P. gregariascomum (MFLUCC 11–0175) both have uni-loculate to multi-loculate conidiomata (Liu et al. 2015). However, C. italica has ampulliform conidiogenous cells, whereas P. gregariascomum (MFLUCC 11–0175) has cylindrical conidiogenous cells instead (Liu et al. 2015). These morphological differences of the sexual (Fig. 2) and asexual (Fig. 3) morphs of Corylicola italica compared to other Bambusicolaceae species, in combination with the results of our multi-locus phylogenetic analysis, allow us to establish Corylicola as a new genus in Bambusicolaceae with C. italica as its type species.
Figure 2. Corylicola italica sp. nov. (MFLU 19–0500, holotype). a–b. appearance of ascomata on a twig of Corylus avellana; c. Longitudinal section of ascomata; d. ascoma neck and ascospore mass (arrowed); e peridium wall; f pseudoparaphyses; g–j. asci; k–l. ascospores; m. germinated ascospore; n–o. culture characteristics on PDA (n = from above, o = from below) Scale bars: a = 200 μm, b–c = 100 μm, d, f–j = 20 μm, e, k–m = 5 μm.
Figure 3. Asexual morph of Corylicola italica sp. nov. on PDA (MFLUCC 20–0111, ex-type). a. conidiomata on PDA; b. vegetative hyphae on agar media; c. longitudinal section of conidiomata; d. conidioma wall; e–h. conidiogenous cells; i–l. conidia. Scale bars: a = 200 μm, b–c = 20 μm, d = 10 μm, e–l = 5 μm.