Fusarium aglaonematis Y. X. Zhang, C. Chen & Manawas., sp. nov. (Figure 2)
MycoBank number: MB 555872; Index Fungorum number: IF 555872; Facesoffungi number: FoF 10837;
Etymology – Epithet refers to the plant from which the type was collected.
Holotype – ZHKUCC 220077
Micromorphology: Pathogenic on Aglaonema modestum. Sexual morph: Not observed. Asexual morph: Sporodochia not observed. Aerial macroconidia straight to falcate, tapering toward the basal part, robust, moderately curved and slender, apical cell papillate; basal cell foot-shaped to barely notched, (0-)1–3(-5)-septate; 0-septate Conidia: 25–35 × 2–3 µm (x̅ = 32 × 3 µm, n=8); 1-septate conidia: 20–30 × 3–4 μm (x̅ = 25 × 3 μm, n = 50); 2-septate conidia: 40–55(–65) × 3–4 μm (x̅ = 49 × 4 μm, n = 9); 3-septate conidia: (25–)45–80 × 3–5 μm (x̅ = 61 × 4 μm, n = 50); 4-septate conidia: 60–75(–80) × 3–4 (–5) μm (x̅ = 68 × 4 μm, n = 6); 5-septate conidia: 85–95 × 4–5 μm (x̅ = 90 × 4 μm, n = 2). Some macroconidia with updiopattachment. Aerial microconidia forming small false heads on the tips of the phialides, Conidiogenous cells 5–20(–30) × (2–)3(–4) μm (x̅ = 14 × 3 μm, n = 50); microconidia reniform to subclavate, smooth- and thin-walled, 0–1(–2)-septate; 0-septate conidia: 5–25 × 2–5 μm (x̅ = 15 × 3 μm, n = 50); 1-septate conidia: 20–30 × 3–4 μm (x̅ = 25 × 3 μm, n = 22);Chlamydospores not observed.
Culture characteristics: Colonial growth rate was 3.3 mm on PDA at 25 ℃ per day. The colony surface floccose with a regular margin, white at first and turned light purple in the centre at the end. In reverse colony white.
Material examined: China, Guangdong province, Guangzhou city, Aglaonema modestum Schott ex Engl., (Araceae). 23rd August 2020, Y.X. Zhang (ZHKU 220044 holotype) ; dry cultures ZHKU 220045, ZHKU 220046 paratype, and living culture, ZHKUCC 220077 ex–holotype; ZHKUCC 220078, ZHKUCC 220079 ex–paratype.
Notes: In the phylogenetic tree, three isolates in this study formed a single lineage with 100% ML bootstrap support and 1.00 BYPP value. Morphologically, Fusarium aglaonematis is distinguished from its closely related taxa, Fusarium panlongense by the size of microconidia and macroconidia (Wang et al., 2022). The length of microconidia and microconidia of new species is longer than that of F. panlongense described by Wang et al (2022). In addition, F. aglaonematis grow slowly (46 mm diam on PDA after 7 d at 25 ℃) than F. panlonge (57–59 mm diam on PDA after 7 d at 25 ℃). When five gene regions were compared between F. aglaonematis (ZHKUCC 220044) and F. panlonge (LC13656), five base pairs difference in cmdA (totally 610 bp), 18 base pairs difference in rpb1 (totally 1525 bp), 48 base pairs difference in rpb2 (totally 1563 bp), 27 base pairs difference in tef 1-α (totally 613 bp), one base pairs difference in β-tubulin (totally 471 bp). Based on phylogenetic analyses and morphological analyses, these isolates causing A. modestum stem rot were identified as a new species.
Fig. 2 | Fusarium aglaonematis. (A–B) Culture characteristics on PDA after 7 days (A, upper view; B, reverse view). (D–F) Macroconidia with updiopattachment from mycelium (D–F) Phialides with aerial macroconidia. (G–I) Phialides of aerial microconidia. (J–M) Macroconidia with updiopattachment. (N–O) Macroconidia germination. (P) Aerial macroconidia. (Q) Aerial microconidia. Scale bars: (C–Q) = 10 μm.