Fusarium mariecurieae Dewing, Visagie & Yilmaz, 2025

Fusarium mariecurieae Dewing, Visagie & Yilmaz sp. nov.

Fig. 4 View Figure 4

Etymology.

Latin, mariecurieae , named after Maria Salomea Skłodowska-Curie (known simply as Marie Curie) (1867–1934), who was a renowned physicist and chemist known for her pioneering research on radioactivity. We also chose this name, as this study was supported by the Marie Skłodowska-Curie Actions ( MSCA) grant (number 101008129), project acronym “ Mycobiomics ”.

Type.

South Africa • Eastern Cape, from mixed pasture samples, May 2020, collected by A. Davis (holotype: PRU (M) 4611 , dried specimen in a metabolically inactive state; ex-type strain: CBS 152079 View Materials = CMW 58673 View Materials = CN 072 A 3 ) .

Description.

Conidiophores borne on aerial mycelium, 13–106 μm tall, unbranched, sympodial or irregularly branched, bearing terminal or lateral phialides, often reduced to single phialides; aerial phialides mono- and polyphialidic, subulate to subcylindrical, proliferating percurrently, smooth- and thin-walled, 3.5–28.5 × 1.5–4 μm, with inconspicuous thickening; aerial conidia ellipsoidal, fusiform, slightly allantoid to falcate, slender, curved dorsiventrally and more pronounced on the apical half, tapering towards both ends, with a blunt to conical and straight to slightly curved apical cell and a blunt to papillate basal cell, 0–3 (– 5) - septate; 0 - septate conidia: 8–11 × 2.5–3 μm (av. 9.6 × 2.6 μm) (n = 2); 1 - septate conidia: 11–20 × 3–4 μm (av. 15.6 × 3.3 μm) (n = 11); 2 - septate conidia: 15–23 × 3–4 μm (av. 18.7 × 3.6 μm) (n = 6); 3 - septate conidia: 18.5–30.5 × 3–5 μm (av. 23.2 × 3.8 μm) (n = 26); 5 - septate conidia: 33 × 5 μm (n = 1). Sporodochia peach to pale straw, formed abundantly on carnation leaves. Sporodochial conidiophores densely and irregularly branched, bearing apical whorls of 2–3 phialides; sporodochial phialides monophialidic, subulate to subcylindrical, 6–22 × 2–4 μm, smooth, thin-walled, with inconspicuous periclinal thickening; sporodochial conidia falcate, curved dorsiventrally, tapering towards both ends, with a slightly curved apical cell and a blunt to foot-like basal cell, (1 –) 3–5 - septate, hyaline, smooth- and thin-walled; 1 - septate conidia: 12–17 × 3 μm (av. 14.4 × 3.2 μm) (n = 2); 3 - septate conidia: 19–36 × 3–4 μm (av. 30.0 × 3.8 μm) (n = 23); 4 - septate conidia: 31–36 × 4–5 μm (av. 33.2 × 4.3 μm) (n = 4); 5 - septate conidia: 30 × 5 μm (n = 1). Chlamydospores not observed.

Culture characteristics.

Colonies on PDA incubated at 25 ° C in the dark with an average radial growth rate of 5–9 mm / d, occupying an entire 90 mm Petri dish in 7 d; surface white, flat, felty to velvety around the centre, floccose towards the margins, radiate, with abundant aerial mycelium, margin irregular, filiform. Additional colony diam (after 7 d): PDA 10 ° C 12–17; PDA at 15 ° C 29–40; PDA at 20 ° C 48–70; PDA at 30 ° C 68–76; PDA at 35 ° C 4–6. Odour absent. Reverse yellowish white (3 A 2). Diffusible pigments absent. On OA in the dark, occupying an entire 90 mm Petri dish in 7 d; surface white, floccose around the centre, flat, felty to velvety towards the margin, radiate, with abundant aerial mycelium, margin irregular, filiform. Reverse yellowish white (2 A 2). Diffusible pigments absent. On SNA with sparse aerial mycelium, sporulation moderate on the surface of the medium.

Additional materials examined.

South Africa • Eastern Cape, from mixed pasture samples, May 2020, collected by A. Davis, isolated by C. Dewing, Humansdorp area : CMW 58664 View Materials = CN 070 E 5 , CMW-IA 002131 = CMW 60929 View Materials = CN 070 F 5 , CMW-IA 003328 = CMW 61372 View Materials = CN 070 G 5 , CMW 58666 View Materials = CN 070 H 6 , CBS 151774 View Materials = CMW 58667 View Materials = CN 070 I 7 , CMW 58668 View Materials = CN 071 B 2 , CMW 58669 View Materials = CN 071 C 1 , CMW 58670 View Materials = CN 071 E 4 , CMW-IA 002136 = CMW 60934 View Materials = CN 071 F 2 , CMW-IA 002137 = CMW 60935 View Materials = CN 071 F 3 , CMW 58671 View Materials = CN 071 F 4 , CMW 58676 View Materials = CN 072 E 2 , CMW 58677 View Materials = CN 104 C 2 , CMW 58678 View Materials = CN 104 E 1 , CMW 58679 View Materials = CN 106 F 1 , CMW 58680 View Materials = CN 106 F 8 , CMW-IA 003763 = CMW 61535 View Materials = CN 106 F 9 , CMW 58681 View Materials = CN 106 G 1 , CMW 58682 View Materials = CN 106 G 2 , CMW 58683 View Materials = CN 106 G 3 , CMW 58684 View Materials = CN 106 G 4 , CN 106 G 5 , CMW-IA 003764 = CMW 61536 View Materials = CN 110 D 9 , CMW 58685 View Materials = CN 110 E 2 , CN 115 C 6 , CN 115 C 9 , CN 115 D 4 , CN 115 E 8 , CMW 61371 View Materials = CN 070 G 1 , Outside Humansdorp, close to Clarkson : CMW 58665 View Materials = CN 070 G 2 , CMW 58672 View Materials = CN 071 H 1 , CMW 58674 View Materials = CN 072 B 2 , close to Villa Fonte : CMW 58675 View Materials = CN 072 B 6 .

Notes.

Fusarium mariecurieae belongs to the Incarnatum - clade and is most similar to an unsupported clade containing the following species: F. caatingaense ( FIESC 20) ( Santos et al. 2019), F. citrullicola (nom. inval.) ( Khuna et al. 2022), F. irregulare ( FIESC 15) ( Wang et al. 2019), F. luffae ( FIESC 18) ( Wang et al. 2019), F. mianyagense ( Han et al. 2023) , F. multiceps ( FIESC 19) ( Xia et al. 2019), F. pernambucanum ( FIESC 17) ( Santos et al. 2019) and F. sulawesiense ( FIESC 16) ( Maryani et al. 2019). Fusarium mariecurieae produces both aerial mono- and polyphialides compared to F. irregulare that only produces monophialides ( Wang et al. 2019), F. luffae that produces only polyphialides ( Wang et al. 2019) and F. mianyagense that lacks aerial phialides ( Han et al. 2023). Aerial conidia from F. mariecurieae (0–3 (– 5) - septate; 8–30.5 × 3–5 μm) are smaller than that of F. irregulare (mostly 3 - septate; 16–38.5 × 3–5 μm) ( Wang et al. 2019), F. luffae (3–5) - septate; 26.5–46 × 4–5 μm) ( Wang et al. 2019), F. multiceps (1 –) 3–4 (– 5) - septate; 16–37 × 3–4 μm) ( Xia et al. 2019), F. pernambucanum (1–7) - septate; 7–57 × 2.5–5 μm) ( Santos et al. 2019) and F. sulawesiense (3–5 (– 9) - septate; 20.5–67 × 3.5–6 μm) ( Maryani et al. 2019). Aerial conidia from F. caatingaense (0–6 - septate; 6–45 × 2.5–5 μm) ( Santos et al. 2019) and F. citrullicola (1–5 - septate; 8–39 × 2–4.9 μm) ( Khuna et al. 2022) were, at their largest, bigger than those of F. mariecurieae , while aerial conidia were absent from F. mianyagense ( Han et al. 2023) . Sporodochia were absent from F. citrullicola , F. irregulare and F. luffae ( Wang et al. 2019) , while chlamydospores were absent from F. irregulare , F. luffae , F. mianyagense , F. multiceps and F. sulawesiense ( Maryani et al. 2019; Wang et al. 2019; Xia et al. 2019; Han et al. 2023). Sporodochial conidia from F. mariecurieae (1–3 (– 5) - septate; 12–36 × 3–5 μm) were smaller than that of F. caatingaense (1–5 - septate; 15–50 × 2–4.5 μm) ( Santos et al. 2019), F. mianyagense (3 (– 5) - septate; 24.5–36.6 × 2.5–4.9 μm) ( Han et al. 2023), F. multiceps (( 1 –) 2–5 - septate; 16–46 × 3–4 μm) ( Xia et al. 2019) and F. sulawesiense (( 3 –) 5 (– 6) - septate; 29.5–43.5 × 4–5.5 μm) ( Maryani et al. 2019). Colony colour on PDA differs between F. mariecurieae and closely related species ( Maryani et al. 2019; Santos et al. 2019; Wang et al. 2019; Xia et al. 2019; Han et al. 2023) as most other species show more colour across the surface and reverse compared to the white surface and yellowish white (3 A 2) reverse of F. mariecurieae . The growth rate after 7 d on PDA for F. mariecurieae is faster (> 90 mm plate) than that of F. citrullicola (68–74.5 mm) ( Khuna et al. 2022), F. irregulare (53–59 mm) ( Wang et al. 2019), F. luffae (53–57 mm) ( Wang et al. 2019) and F. mianyagense (74–80 mm) ( Han et al. 2023). The growth of F. multiceps (> 90 mm plate) ( Xia et al. 2019) is similar to that of F. mariecurieae , while the growth rate in terms of diameter was not reported for F. caatingaense , F. pernambucanum and F. sulawesiense ( Maryani et al. 2019; Santos et al. 2019). Pairwise comparisons revealed that F. mariecurieae differs from other species by at least 1, 4 and 12 bp for CaM, RPB 2 and TEF, respectively.