Fusarium equiseti
From Species-ID
Contents
Fusarium equiseti (Corda) Sacc. — Syll. Fung. 4: 707. 1886.
- = Selenosporium equiseti Corda — Icon. Fung. 2: 7, Tab. IX, Fig. 32. 1838.
- = Fusarium gibbosum Appel & Wollenw. — Arb. Kais. Biol. Anst. Land- Forstwirtsch. Berlin-Dahlem 8: 185–190, 1910 emend. Bilai — Fusarii: 261–263, 1955 (pro maxima parte).
- Holotype specimen — Czech Republic, Bohemia, Chuchle (Kuchelbad) near Praha, leg. Corda, s.d., PRM No. 155622. — Fig. 2.
- Neotype specimen — Germany, Niedersachsen, Braunschweig, soil, isolated by H.I. Nirenberg, March 1994, CBS H-5570.
- Isoneotype specimens — CBS H-7148; CBS H-7149; CBS H-7150; CBS H-7151; CBS H-7152; CBS H-7153; CBS H-7154.
Teleomorph
Gibberella intricans Wollenw. — Z. Parasitenk. 3: 332, 1931.
Material examined
The following species description was taken from Gerlach & Nirenberg 1982
Colony morphology
- Colonies — generally fast-growing or very fast-growing, reaching 6.0–8.0 cm diam. in 6 days at 25C on PDA; considerable differences between different strains.
- Aerial mycelium — usually abundant, loosely floccose, sometimes more felt-like, in some strains only sparse, whitish to peach, ochraceous or buff-brown.
- Pigmentation — beige, yellowish brown, ochraceous, amber, avellaneous, buff-brown to coffee-brown, sometimes blackish brown, never red, vinaceous, violet or bluish.
- Sclerotial bodies — often present, sometimes rather abundant, of different shape and size, pale brownish, becoming dark brown.
- Sporulation — in most strains only sparse in the aerial mycelium or lacking, in some sporodochia or expanded pionnotes formed early and abundantly, at first pale, yellowish ochraceous to salmon, when desiccating becoming honey to cinnamon-brown or brighter coloured.
- Odour — not perceptible.
Micromorphology
- Conidiophores — initially arising as single lateral phialides in the aerial mycelium or branching loosely, when formed in sporodochia very densely branched, compact, terminating in 1-3 or more phialides.
- Phialides — monophialidic, usually short, compact, obclavate to dolii-form, mostly 10–15 µm long and 3–4 µm wide.
- Conidia — only macroconidia formed, sometimes few or numerous 0- to 1-septate conidia present, very great differences in size and shape between different strains, rather thick-walled, typically falcate, parabolic or hyperbolic, gradually tapering toward both ends, somewhat curved with a more blunt apical cell (corresponding to var. bullatum) or strongly bent mainly in the central part with a more or less distinctly elongated, straight or whip-like bent apical cell (corresponding to F. scirpi var. filiferum) and a very distinctly pedicellate basal cell, mostly 3- to 5-(up to 7-)septate, less frequently 0- to 2-, exceptionally 8- to 12-septate, measuring:
- 0-sept. 9 × 2.8 mostly 7–12 × 2. 5–3.3 (5–18 × 2.0–6.0) µm
- 1-sept. 14 × 3.1 mostly 10–17 × 2.5–3.6 (8–24 × 2.0–4.5) µm
- 3-sept. 27 × 3.9 mostly 15–35 × 2.8–5.0 (10–55 × 2.3–6.5) µm
- 4–5-sept. 46 × 4.4 mostly 25–65 × 3.0–5.5 (20–87 × 2.8–6.0) µm
- 6–7-sept. 59 × 4.8 mostly 45–70 × 4.0–5.5 (30–90 × 3.5–6.0) µm
- 8–12-sept. 69 × 5.3 mostly 55–83 × 4.5–6.0 (51–132 × 3.5–6.3) µm.
- Chlamydospores — early and abundantly formed in hyphae, less frequently in conidia, most often intercalary, solitary, in pairs, frequently forming chains or clusters, globose to subglobose (8–20 µm), smooth- or rough-walled, becoming ochraceous.
Discussion
This Fusarium is a cosmopolitan soil fungus and has been isolated from roots, crowns, stems, leaves, fruits, seeds, tubers and other parts of very numerous plant species, cereals in particular, including maize, in temperate to subtropical areas. As a plant pathogen it is most frequently recorded in connexion with root, tuber, stem and fruit rots. By and large, the fungus seems to be only mildly parasitic and of comparatively minor economic importance. JOFFE & PALTI (1967), however, stated that in Israel its pathogenic capabilities have been underestimated. More detailed information is given by BOOTH (1971), BOOTH (1978) and DOMSCH et al. (1980).
