Appendopyricularia guttulata Y. Wang, H.W. Shen & Z.L. Luo

Wang, Ying, Bao, Dan-Feng, Shen, Hong-Wei, Yang, Lin & Luo, Zong-Long, 2024, Appendopyricularia guttulata sp. nov., a lignicolous freshwater fungus from Dianchi Lake in Yunnan, China, Phytotaxa 660 (1), pp. 55-64 : 58-59

Appendopyricularia guttulata Y. Wang, H.W. Shen & Z.L. Luo , sp. nov. FIGURE. 2

Fungal Names number: FN 571910

Etymology:— Referring to the conidia with large guttules.

Holotype:— KUN-HKAS 130433

Saprobic on submerged decaying wood in freshwater habitats. Sexual morph: Undetermined. Asexual morph: Colonies on substratum superficial, effuse, dark brown. Mycelium partly immersed, branched, smooth, brown, septate hyphae. Conidiophores 92–117 × 4–6 μm (x = 104.5 × 5 μm, n = 20), macronematous, mononematous, erect, straight or slightly flexuous, smooth, brown to hyaline thick-walled, 3–5-septate. Conidiogenous cells 43–53 × 4–5 μm (x = 47.7 × 4.8 μm, n = 18) integrated or branched, terminal, polyblastic, hyaline, subdenticulate. Conidia 30–33 × 4–5 μm (x = 31.5 × 4.9 μm, n = 30), acrogenous, solitary, hyaline, smooth, guttulate, fusoid, 3–4-septate, hilum truncate, with flexuous central apical appendage, 22–29 µm long.

Culture characteristics: Conidia germinating on PDA within 12 hours and germ tubes produced from the basal, apical and periphery cell of conidia. Colonies growing on PDA, reaching 10 mm diameter in 10 days at 22 ◦ C, with sparse to moderate aerial mycelium and feathery margins, circular, edge entire, surface white, reverse honey to white. Material examined: China, Yunnan Province, Dianchi Lake (Altitude: 1,860m, 24°49′14.1567″N, 102°45′57.5845″E), on submerged decaying wood, 18 February 2023, Hong-Wei Shen, L-1636 (KUN-HKAS 130433, holotype), ex-type culture, CGMCC 3.25401= KUNCC 23-13169.

Notes: Appendopyricularia juncicola was introduced by Crous et al. (2022) based on morphological and phylogenetic evidence. In the multigene phylogenetic analysis of this study, Appendopyricularia guttulata clustered to A. juncicola with 100% ML and 1.00 PP statistical support. Morphologically, A. guttulata has longer conidiophores than A. juncicola (92–117 × 4–6 μm vs. 7–30 × 3–4μm), and the central apical appendage of A. guttulata is longer than A. juncicola (22–29 vs. 4–15 µm). The conidia of A. guttulata (30–33 × 4–5 μm) are larger than A. juncicola (15–20 × 3–4 µm), and with 3–5 larger guttulate cells. In addition, comparison of ITS sequences between A. guttulata and A. juncicola showed 3.68% (18/489 bp) nucleotide differences with 7 gaps. Based on morphological and phylogenetic analysis, we introduce A. guttulata as a new species.

Figures

FIGURE 2. Appendopyricularia guttulata (KUN-HKAS 130433, holotype). (a–b) Colonies on submerged decaying wood; (c–f) Conidiophores and conidia; (g–j) Conidiogenous cells; (k–n) Conidia; (o) Germinating conidium; Culture on PDA from front (p) and reverse (q). Scale bars: (c–f) 30 µm; (j) 40 µm; (g–i, k–o) 50 µm.