Crown rot of seedlings and young plant of groundnut. Infected plants wilt and die. Stem and taproot become shredded. Associated with neck rot of onion, harvest mould of maize and copra, spoilage of stored grain and seeds, and other food products (e.g., dried fruit). Very common on decaying vegetable matter and in soil.
Morphology
Conidiophores arising singly, hyaline or with the upper part brown, smooth, few or no septa, up to 3 mm long, 15–20 µm thick, swollen at the apex into a vesicle; vesicle spherical, 40–75 µm diam., covered in short terminal branches (metulae), each 30–30 × 5–6 µm, branches narrowest at base, widest near apex. Conidiogenous cells phialidic, in groups of 2–3 at the apex of each terminal branch, flask-shaped, 7–10 µm long, 3–4 µm wide in middle, 1–1.5 µm wide at apex. Conidia in dry chains, globose, (3–)4–5 µm diam., brown, verruculose or echinulate; conidial heads dark brown to black, initially globose but often splitting into well-defined conidial columns.
Notes
Aspergillus niger is one of the black aspergilli (Aspergillus section Nigri; Gams et al. 1985). Varga et al. (2007) described A. brasiliensis as a widespread segregate from A. niger, based on gene sequence differences and extrolite production profile. It is probable that many records of A. niger refer to a segregate species.
