Holmiellales » Holmiellaceae » Holmiella

Holmiella junipericola

Holmiella junipericola Pem, Gafforov, Jeewon & K.D. Hyde, Cryptog. Mycol. 39(2): 200 (2018) amend.
MycoBank: MB 825002
Other specimens examined: Oman.
Saprobic on dead trunks and branches of Juniperus seravschanica. Sexual morph: Ascomata 0.4–0.8 mm diam., apothecial, solitary to gregarious in groups of a few, superficial, sessile, at first pulvinate and covered with a continuous outer layer, outer layer splitting irregularly into 3–6 lobes that fold back to expose a black hymenium, sub-gelatinous when rehydrated, with smooth outer surface of the receptacle, black. Exciple consisting of a dark-brown, leathery layer, 20–50 μm thick, pseudoparenchymatous, two-layered; outer layer thick, comprised of dark brown to black, slightly cracked cells of textura angularis; inner layer, thin, composed of light brown cells of textura epidermoidea. Subhymenium inverted conically, of marginally elongated and more or less horizontally oriented brown cells. Hypothecium prosenchymatous consisting of textura intricate, light brown, 10–35 μm tall below the subhymenium base to 0.5 mm diam. Hamathecium 1–2 μm wide, filiform, branched, interwoven hyphal filaments, forming a dark brown epithecium above the asci. Asci 100–145 × 35–45 μm, 8-spored, clavate, bitunicate, fissitunicate, with an ocular chamber in the apical dome. Ascospores 26–38 × 10–18 μm, irregularly 2–3 seriate, overlapping, ellipsoidal, 1-septate in the middle and slightly constricted at the septum, slightly granulated, ranging from hyaline when immature to light brown and dark brown when mature, with a hyaline papilla at the ends, upper cell slightly wider than lower cell, thick and smooth-walled. Asexual morph: corniculariella-like. Conidiomata pycnidial, 0.5–1 mm diam., globose, black, superficial or immersed in PDA. Phialides cylindrical to sub-cylindrical, 12–20 μm long, tapering from 1.5–2 μm wide basally to 1–1.5 μm wide at the unflared opening, solitary or in pairs, arising from short conidiophores. Conidiophores branched, hyaline, septate. Conidiogenous cells integrated. Conidia stylosporous, 14–22× 0.5–1.5 μm, straight to sharply curved, unicellular, hyaline.
Culture characteristics—Colonies on PDA slow growing reaching 2 cm diam. In 10 days, green to olivaceous green, flat, with moderate aerial mycelium, smooth, crenate margin.
Material examined—OMAN, Al Jabal al-Akhdar (Green Mountain), from dead branches of Juniperus seravschanica, 07.2016, SSN Maharachchikumbura OM07 (SQU H-116), living culture = SQUCC 15186.

GenBank accession numbers: LSU: MW077151; SSU: MW077160; ITS: MW077142; TEF: MW075769; RPB2: MW276074.
Notes—Pem et al. (2018) introduced Holmiella junipericola, which was collected on dead trunks and branches of Juniperus seravschanica Kom. (as J. zerawschanica Kom. in the paper) in Uzbekistan. Hitherto, only the sexual morph of this species was reported and unidentified asexual structures of chlamydospores were observed. In this study, isolate SQUCC 15186 producing both sexual and asexual morphs was collected on J. seravschanica, which is the dominant dry, temperate tree species of woodlands in the higher elevations of the Al Jabal Al Akhdar mountains in Oman. Pem et al. (2018) clearly showed that H. junipericola differs from H. sabina (type species of the genus) in having larger ascomata, different numbers of globules per ascospore cell and the shape of the ascospore apex. They
also compare the sequence data of H. junipericola with the GenBank isolate of G.M. 2015-04-29.2 named as H. sabina. However, it is noted that this isolate is not related to the type material, nor it is linked to a specimen that can be compared with morphology. In future studies, it is essential to sequence the type species of the genus Holmiella.

 

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