Phyllachora yuanjiangensis H. X. Wu &amp; J. C. Li. 2023, sp. nov.
Creators: name: Li, Jin-Chen
name: Wu, Hai-Xia
name: Song, Jia-Yu
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Fungi
Ascomycota
Dothideomycetes
Botryosphaeriales
Phyllostictaceae
Phyllachora
Phyllachora yuanjiangensis

description: <i>Phyllachora yuanjiangensis</i> H.X. Wu &amp; J.C. Li. <i>sp. nov</i>. Fig. 3 MycoBank: 845540 <b>Etymology—</b> Epithet derived from the type locality. <b>Holotype —</b> IFRD9466 <i>Parasitic</i> on leaves and stems of <i>Arundinella setosa</i> (Poaceae). <b>Sexual morph</b>: <i>Stromata</i> 360–750 × 105–195 μm (<i>x</i> = 570 × 147.5 μm, n = 10), fusiform or cymbiform, domed above the leaf surface, amphigenous, scattered, sometimes gregarious, like black nevus, black and carbonaceous. Section of stroma 190–340 μm high, multilocular, peridium, composed of brown to dark brown cells of <i>textura angularis</i>. <i>Paraphyses</i> 2–3 μm wide, numerous, persistent, filiform, unbranched, aseptate, many guttules, slightly longer than asci. <i>Asci</i> 71–112 × 11–22 μm (<i>x</i> = 84.6 × 13.2 μm, n = 20), thin-walled, 8-spored, persistent, cylindrical to clavate, apex obtuse, with pedicel. <i>Ascospores</i> 15–21 × 7–9 μm (<i>x</i> = 17.9 × 8.3 μm, n = 20), 1-seriate, tear-shaped, rounded at the apex, tapered at the base, hyaline, aseptate, verrucous, with guttules and a mucilaginous sheath. <b>Asexual morph</b>: Not observed. <b>Material examined—</b> CHINA. Yunnan Province: Yuanjiang County, on stems and leaves of <i>Arundinella setosa</i>, 101.47°E, 23.27°N, 1532.65 m, 27 November 2021, H. X. Wu &amp; J. C. Li. IFRD9466, holotype. GenBank accession numbers: LSU: OP359417; ITS: OP359399; SSU: OP359400 <b>Note:</b> In the phylogenetic tree (Fig. 1), <i>P. yuanjiangensis</i> is closely related to <i>P. arundinellae</i> and <i>P. xinpingensis</i>. <i>P. yuanjiangensis</i> and <i>P. arundinellae</i> both occur on <i>Arundinella</i> sp. Morphologically, the asci and ascospores of <i>P. yuanjiangensis</i> are longer and wider than those of <i>P. arundinellae</i> (asci 71–112 × 11–22 μm vs 70–100 × 7–10 μm, ascospores 15–21 × 7–9 μm vs 10–18 × 5–8.5 μm). The ascospores of <i>P. yuanjiangensis</i> are tear-shaped, rounded at the apex, tapered at the base, while <i>P. arundinellae</i> is narrowly oval to ovoid. Differences in morphological characteristics and their hosts are also supported by the phylogenetic tree. Four <i>Phyllachora</i> species have been recorded on <i>Arundinella</i> spp., namely <i>P. arundinellae</i>, <i>P. graminicola</i>, <i>P. graminis</i>, and <i>P. shiraiana</i>. <i>P. yuanjiangensis</i> can be distinguished from these species by the shape of its ascospores. The closest hits using LSU and ITS sequences had the highest similarity to <i>P. arundinellae</i> isolate MHYAU:108 (GenBank LSU: MG269815, identities = 809/899 (90%); ITS: MG269761, identities = 440/534 (82%)) and <i>P. graminis</i> MM-166 (GenBank ITS: KX451869, identities = 317/556 (57%)). <i>P. yuanjiangensis</i> had the highest similarity to <i>P. xinpingensis</i> IFRD 9465 (GenBank LSU: OP359416, identities = 885/899 (98%); ITS: OP359399, identities = 496/519 (96%)) but these two species can be distinguished by the host plants and asci length. A synopsis of <i>P. yuanjiangensis</i> and other <i>Phyllachora</i> species recorded from <i>Arundinella</i> spp. is provided (Table 2).
description: Published as part of <i>Li, Jin-Chen, Wu, Hai-Xia &amp; Song, Jia-Yu, 2023, Two new Phyllachora species in Southwest China, pp. 275-285 in Phytotaxa 578 (3)</i> on pages 282-283, DOI: 10.11646/phytotaxa.578.3.5, http://zenodo.org/record/7523156