Phaeoisaria ellipsoidea R. Zhu & H. Zhang, 2023

Yang, Jun-Xian, Zhang, Huang, Wang, Lin, Zhu, Rong, Dong, Wei & Chen, Shou-Yue, 2023, Phaeoisaria ellipsoidea (Pleurotheciaceae, Pleurotheciales, Sordariomycetes), a new lignicolous freshwater fungus from Xishuangbanna, Yunnan Province, China, Phytotaxa 591 (1), pp. 19-30 : 25

Phaeoisaria ellipsoidea R. Zhu & H. Zhang , sp. nov.

FIGURE 2

Index Fungorum number: IF900262, Facesoffungi number: FoF 14019

Etymology: – In reference to the ellipsoidal conidia

Holotype: – IFRD 9462

Saprobic on decaying wood submerged in freshwater. Sexual morph:Undetermined. Asexual morph: Hyphomycetous. Synnemata 6–22(–28) μm wide (x = 12.8 μm, n = 10), erect, rigid, dark brown to black, velvety, smooth, composed of compactly and parallelly adpressed conidiophores, with flared conidiogenous cells in the above half. Conidiophores up to 1.2 mm long, macronematous, synnematous, branched, brown to black, with paler apical cells, smooth. Conidiogenous cells 5.5–13.5 × 2–5 μm (x = 9 × 3.5 μm, n = 20), polyblastic, terminal, discrete, recurved, smooth, sympodial, denticulate, each with several denticulate conidiogenous loci, subhyaline to light brown. Conidia 4–8 × 3–4.5 μm (x = 6.5 × 4 μm, n = 20), narrowly ellipsoidal to obovoid, rounded at the apex, hyaline, aseptate, guttulate, smooth.

Culture characteristics: Colonies on PDA reaching 30 mm diam. at 20–25˚C after 5 weeks. Surface gray flat, dry, rough, margin undulate and irregular, with sparse mycelium. Reverse dark brown to black.

Material examined: China, Yunnan Province, Xishuangbanna, Man Feilong reservoir, on submerged decaying wood of unidentified plants, 7 November 2020, R. Zhu, N 11 ( IFRD 9462 , holotype), ex-type living culture IFRDCC 3134 .

Notes: The multi-locus phylogenetic analyses show that P. ellipsoidea forms a distinct lineage in Phaeoisaria and groups with P. clematidis , P. dalbergiae and P. laianensis ( FIGURE 1 ). Comparing to the three species, P. ellipsoidea has the longest conidiophores (up to 1210 μm vs. 28–46 μm in P. clematidis vs. 10–50 μm in P. dalbergiae vs. 116–491 μm in P. laianensis ) ( Luo et al. 2018, Crous et al. 2021, Liu et al. 2022). Phaeoisaria ellipsoidea can be distinguished from P. clematidis and P. dalbergiae by different shape of conidia (narrowly ellipsoidal to obovoidal with rounded apex vs. narrowly obovoidal with tapering base in P. clematidis vs. subcylindrical to obovoid, tapering towards both ends in P. dalbergiae ) ( Luo et al. 2018). Additionally, P. ellipsoidea differs from P. laianensis in having slightly wider conidia (3–4.5 μm vs. 1.7–2.9 μm) ( Liu et al. 2022). The strains MFLUCC 16-1273 and MFLUCC 17-1341 of P. clematidis have nearly identical nucleotides in ITS loci, which are 24 differences (3.8%, including 13 gaps) from P. ellipsoidea . There are 33 (4.9%, including 13 gaps) and 46 (6.9%, including 16 gaps) base pairs differences in ITS loci between P. ellipsoidea and P. dalbergiae , P. ellipsoidea and P. laianensis , respectively. Following the generally accepted norm that more than 1.5% of nucleotide differences in the ITS region is likely to be a new species, P. ellipsoidea is introduced as a new species ( Jeewon & Hyde 2016).

Figures

FIGURE 1. Maximum likelihood majority rule consensus tree for Pleurotheciaceae based on a dataset of combined LSU, SSU, ITS and rpb2 sequence data. Bootstrap support values for maximum likelihood (the first value) equal to or greater than 75% and Bayesian posterior probabilities (the second value) equal to or greater than 0.95 are given above the nodes as MLBS/BIPP. The strain numbers are noted after the species names. Newly generated sequences are indicated in red, and ex-type strains are in bold. The tree is rooted with Conioscypha peruviana (ILL 41202) and C. pleiomorpha (FMR 13134).

FIGURE 2. Phaeoisaria ellipsoidea (IFRD 9462, holotype) a, b Colonies on the natural substratum. c, d Conidiophores with conidia. e, f Conidiogenous cells bearing conidia. g–n Conidia. o Colony on PDA (from front). p Colony on PDA (from reverse). Scale bars: c = 50 μm, d = 80 μm, e = 10 μm, f–n = 2 μm.