Khaleijomyces umikazeanus Abdel-Wahab sp. nov.

Index Fungorum number: IF 557837; MycoBank number: MB 557837; Facesoffungi number: FoF 09201; Fig. 1

Etymology – Named after Umikaze Beach, where this fungus was collected.

Holotype – CBS H-23860

Saprobic on the surface of driftwood in the intertidal zone. Sexual morph Ascomata 110–200 μm diam. (x̅=144 μm, n=8), superficial, solitary, scattered on substrate, subglobose to globose, coriaceous, apricot reddishbrown. Necks 130–180 μm long, 40–50 μm wide, hyaline to apricot in colour, periphysate. Peridium 18–28 μm wide, forming textura angularis, two-layered; outer layer 11–16 μm wide, 4 to 11 layers of apricot to reddish-brown, thick-walled, polygonal to flattened cells; inner layer 9–13 μm wide, 4 to 10 layers of hyaline, thick-walled, polygonal to flattened cells. Paraphyses 2–4 μm wide, septate with swollen cells, constricted at the septa, embedded in gel, attached to the top and the base of the ascomatal venter. Asci 73–83 × 9–11 μm (x̅= 81 × 10 μm, n = 20),8-spored, unitunicate, thin-walled, persistent, fusiform, curved, developing from ascogenous tissue at the base of the ascomata. Ascospores 19–24×5–6 μm (x̅=22×6 μm, n=40), 1–3-seriate, fusiform to clavate, with rounded ends, 3-septate, not constricted at the septa, hyaline to faint apricot in colour, surrounded by a deciduous amorphous material. Asexual morph Undetermined.

Culture characteristics – Ascospores germinating on PDA within 24 h at 25 °C and germ tubes produced from the ends of the ascospore. Colonies on PDA reaching 2 cm diam. after 3 weeks, at 25 °C, white to yellow–brown, white from below.

Material examined – JAPAN, Yokosuka City, Umikaze Beach, on decaying driftwood in the intertidal zone, 4 August 2008, M.A. Abdel-Wahab (CBS H-23860, holotype), ex-type living culture, NBRC 105287.

GenBank numbers – LSU = MN921253, SSU=MN921252.

Notes – Combined phylogenetic analyses of SSU and LSU rDNA placed Khaleijomyces umikazeanus as a distinct species. It grouped with K. marinus in phylogenetic analysis but with low statistical support. Khaleijomyces umikazeanus differs from K. marinus in having 3-septate, hyaline ascospores, while those in the latter species are unicellular when young that become 1–4-septate and yellow–brown to brown in older specimens. The outer layer of the peridium in K. umikazeanus is textura angularis while K. marinus is textura epidermoidea. The hamathecium in K. umikazeanus forms persistent paraphyses, embedded in gel and attached to the top and the bottom of the ascomatal venter, while it is pseudoparenchymatous in K. marinus that fills the young ascomatal venter and breaks down into catenophyses that become deliquescent early (Abdel-Wahab et al. 2018). Khaleijomyces umikazeanus differs from Fulvocentrum species in having asci without an apical apparatus and wide and septate paraphyses (2–4 μm wide). The asci in Fulvocentrum species either have apical thickening in F. aegyptiacum and F. clavatisporum, and apical ring in F. rubrum. The hamathecium in Fulvocentrum species are narrow (1–2 μm wide), numerous and aseptate (Abdel-Wahab et al. 2001, 2019). Khaleijomyces umikazeanus also differs from Fulvocentrum species in the morphology of ascomata, asci and ascospores and are phylogenetically distant (Figs. 1 and 2).

Figure 1 – Khaleijomyces umikazeanus (CBS H-23860, holotype). a Squash of ascoma. b Vertical section through ascoma. c Close up of neck show periphyses. d Close up of peridium. e, f Asci and paraphyses. g Ascal tips. h, i Ascospores with amorphous material. Scale bars: a, b=60 µm, c, d, g–i=10 µm, e, f=15 µm

Figure 2 – Phylogenetic relationship of Khaleijomyces umikazeanus with related taxa in Juncigenaceae based on the nucleotide sequences of the combined SSU and LSU rDNA. The maximum likelihood (ML) tree (-ln likelihood=14429.06) was constructed in PAUP 4 (Swofford 2002). The maximum parsimonious data set of the combined genes consisted of 35 taxa with 3 representatives of Xylariales used as outgroup. The combined dataset includes 1116 total characters, of which 712 were constant, 89 parsimony-uninformative and 315 parsimony-informative. The parsimony analyses of the data matrix yielded 2 equally most parsimonious trees with a tree length of 1084 steps [consistency index (CI)=0.5424, homoplasy index (HI)=0.4576, retention index (RI)=0.7385, rescaled consistency index (RC)=0.4005]. Phylogenetic trees obtained from ML, maximum parsimony (MP) and Bayesian inference posterior probabilities (BYPP) were similar in topology. Bootstrap support on the nodes represents MLBS and MPBS equal to or greater than 50%. Branches with a BYPP of equal to or greater than 0.95 are in bold. The newly taxon is in yellow box