Montagnula jonesii
Montagnula jonesii Tennakoon, Wanas., Phook. & K.D. Hyde, in Tennakoon, Hyde, Wanasinghe, Bahkali, Camporesi, Khan & Phookamsak, Mycosphere 7(9): 1350 (2016)
Holotype – MFLU 16-1363
Index Fungorum number: 552577; Facesofungi number: FoF 02719
Etymology – In honour of Professor E.B. Gareth Jones for his immense contribution to mycology Saprobic on dead branches of Fagus sylvatica L. Sexual morph: Ascomata 140–210 µm diam., solitary, scattered to clustered, immersed or erumpent through host surface, visible as slightly raised, brown spots on host surface, globose to subglobose, glabrous, uniloculate, ostiole central with minute papilla. Peridium 10–25 µm wide, thin-walled with equal thickness, slightly thin at the base, composed of two layers of pseudoparenchymatous cells, inner layer comprising several cell layers of flattened, hyaline cells, arranged in a textura prismatica, outer layer comprising several layers of dark brown to black cells, arranged in a textura angularis. Hamathecium composed of 2–2.5 µm wide, dense, broad, filamentous pseudoparaphyses, distinctly septate, not constricted at the septum, anastomosing at the apex, embedded in a hyaline, gelatinous matrix. Asci (53–)60–70(–83) × (7.6–)9–10(–11.5) µm (x̄ = 66.8 × 9.5 µm, n = 35), 8-spored, bitunicate, fissitunicate, clavate, long pedicellate, apically rounded, with well-developed ocular chamber. Ascospores 14–16(–17) × 4–5.5 µm (x̄ = 15.5 × 5 µm, n = 35), overlapping 1–2-seriate, initially hyaline to pale brown, becoming brown to reddish-brown at maturity, ellipsoidal to fusiform with rounded ends, 1 -septate when young, becoming 3-septate when mature, constricted at the septa, straight to curved, enlarge at the second cell from apex, smooth-walled, with guttules. Asexual morph: Undetermined.
Material examined: ITALY, Arezzo Province (AR), near Croce di Pratomagno, on aerial and dead branches of Fagus sylvatica (Fagaceae), 21 June 2015, E. Camporesi, IT 2545 (MFLU 16-1363, holotype; HKAS93702, isotype), ex-type living cultures, MFLUCC 1 6-1448, KUMCC 15-0556.
GenBank Numbers: LSU: KY273276; SSU: KY313618; ITS: KY313619; tef1-α: KY313620.
Note: Montagnula jonesii resembles to M. aloes Crous and M. scabiosae in having reddish-brown, 3-septate ascospores and immersed ostiolate ascomata. Montagnula jonesii has an unique character that can be used to distinguish it from M. aloes and M. scabiosae as ascospores have an enlarged second cell from the apex. Additionally, the size of asci and ascospores are different in each species. Montagnula jonesii has ellipsoidal to fusiform ascospores, while they are ellipsoidal to ovoid in M. aloes. Montagnula jonesii is deeply constricted at septa, whereas M. scabiosae is slightly constricted.
Figure x. Montagnula jonesii (MFLU 16-1363, holotype). a Ascomata visible as black dots on the host surface. b Vertical section of ascoma. c Section through peridium. d Pseudoparaphyses. e–h Asci i–k Ascospores. l Germinated ascospore. m Colony from above. n Colony from below. Scale bars: b = 50 µm, c = 10 µm, d–l = 5 µm.
References:
Tennakoon DS, Hyde KD, Wanasinghe DN, Bahkali AH 2016 – Taxonomy and phylogenetic appraisal of Montagnula jonesii sp. nov. (Didymosphaeriaceae, Pleosporales). Mycosphere 7: 1346–1356.