Xylochrysis aquatica J. Y. Song &amp; X. D. Yu
Creators: name: Song, Jing-Yi
name: Yang, Yi
name: Yu, Xian-Dong
name: Dissanayake, Asha J.
name: Tian, Qing
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Sordariomycetes
Woswasiaceae
Xylochrysis
Xylochrysis aquatica

description: <i>Xylochrysis aquatica</i> J.Y. Song &amp; X.D. Yu <i>sp. nov.</i> (FIG. 2) <i>MycoBank</i>: MB844596 <i>Etymology</i>: In reference to the aquatic habitat of the fungus <i>Holotype</i>: HKAS 124019 <i>Saprobic</i> on submerged decaying wood in a freshwater stream. <b>Sexual morph:</b> <i>Ascomata</i> 160–265 µm diam. × 145– 290 µm high (<i>x</i> = 200 µm × 205 µm, n = 10), solitary, scattered, immersed to slightly erumpent, globose to subglobose, nonstromatic, uniloculate, glabrous, without a golden yellow layer of surrounding cells at the basal venter, ostiolate. <i>Ostiole</i> 65–135 µm long, 65–130 µm diam. (<i>x</i> = 108 µm × 96 µm, n = 10), black, papillate, glabrous, shiny, lined with hyaline periphyses. <i>Ascomatal wall</i> multi-layered, outer layers 12–47 µm thick, composed of brown to dark brown cells of <i>textura angularis</i>, carbonized and form a thicker layer in the lower part of the ostiole, inner layers 13–33 µm, comparatively thick, composed of flattened, hyaline cells of <i>textura prismatica</i>. <i>Hamathecium</i> 2.5–5.0 µm wide (<i>x</i> = 4.0 µm, n = 30), comprising numerous, narrowly cylindrical to filiform, branched, septate paraphyses, not embedded in a gelatinous matrix. <i>Asci</i> 68–120 µm × 3.0–6.5 µm (<i>x</i> = 96.0 × 4.5 µm, n = 30), 8-spored, unitunicate, cylindrical, long pedicellate, tapering to the bulbose base, apically rounded with an apical ring. <i>Ascospores</i> 4.5–6.5 µm × 2.5–4.0 µm (<i>x</i> = 6.0 × 3.0 µm, n = 30), L/W 1.5–2.5 (<i>x</i> = 2.0, n = 30), uniseriate, ellipsoidal, hyaline, aseptate, straight, 2-guttulate, thin-walled, smooth-walled, without mucilaginous sheath or appendages. <b>Asexual morph:</b> Undetermined. <i>Culture characteristics:</i> Ascospores germinated on PDA within 24 hours, and germ tubes were produced from both ends of the ascospores. Colonies growing on PDA reaching a diameter of 20 mm after 24 days at 25 °C, rough, irregular, slightly raised, edge crenate, with both surfaces dark-gray in the margin and grayish-white towards the center, slowly growing, reverse taupe brown, without sporulation. <i>Material Examined:</i> CHINA, Sichuan province, Chengdu, Pengzhou county, Huilonggou Scenic Area, (31°14′21″ N, 103°47′28″ E), on a submerged decaying wood of undetermined host, 28 July 2021, Xian-Dong Yu (HKAS 124019, <b>holotype</b>; HUEST 22.0028, <b>isotype</b>); ex-type culture CGMCC 3.23639 (= UESTCC 22.0030). <i>Notes: Xylochrysis aquatica</i> fits well with the morphological characteristics of <i>Xylochrysis</i> in having globose ascomata, numerous paraphyses, cylindrical and long pedicellate asci, ellipsoidal and hyaline ascospores (Réblová <i>et al.</i> 2014). <i>Xylochrysis aquatica</i> is easily distinguished from the type species <i>X. lucida</i> by solitary, scattered, smaller ascomata (160–265 µm × 145–290 µm vs. 350–500 µm × 350–500 µm) without a layer of colored cells surrounded, longer asci (60–120 µm long vs. 59–73 µm long) and more rounded ascospores (L/W: 1.5–2.5 µm vs. 2.2–2.8 µm). Ascomata of <i>X. lucida</i> often aggregated or confluent in groups of 3–10 and surrounded by a golden yellow layer of cells. In addition, the ostiolar neck of <i>X. lucida</i> is short-beaked and distinctly longer (Réblová <i>et al.</i> 2014) than our new taxon, <i>X. aquatica</i>. The multi-gene (ITS-LSU-SSU- <i>tef1-α -rpb2</i>) phylogenetic analyses suggested that our isolate clustered together with the generic type <i>X. lucida</i> and formed a distinct lineage (100% ML; 1.00 PP) in <i>Woswasiaceae</i>. In addition, a nucleotide comparison of <i>X. aquatica</i> (CGMCC 3.23639) and <i>X. lucida</i> (CBS 135996) revealed 25 basepair (5 %) and 70 base-pair (7.2 %) differences in ITS (+ 5.8S) and <i>rpb2</i>, respectively (TABLE 2). <i>Xylochrysis aquatica</i> is introduced as a new species based on the moprhology and phylogeny evidences.
description: Published as part of <i>Song, Jing-Yi, Yang, Yi, Yu, Xian-Dong, Dissanayake, Asha J. &amp; Tian, Qing, 2023, Xylochrysis aquatica sp. nov. (Woswasiaceae) from freshwater habitats in Sichuan Province, China, pp. 31-38 in Phytotaxa 587 (1)</i> on pages 34-35, DOI: 10.11646/phytotaxa.587.1.4, http://zenodo.org/record/7710702
description: {"references": ["Reblova, M., Stepanek, V. &amp; Schumacher, R. K. (2014) Xylochrysis lucida gen. et sp. nov., a new lignicolous ascomycetes (Sordariomycetidae) with holoblastic conidiogenesis. Mycologia 106: 564 - 572. https: // doi. org / 10.3852 / 13 - 266"]}