Aureobasidium Viala & G. Boyer, Rev. gén. Bot. 3: 371 (1891).
Parasitic or saprobic on plants, fruits and pathogenic to human. Some plant pathogens form kabatiella-like synasexual morphs which cause leaf spots. They form sub circular irregular, amphigenous, necrotic, sunken, pale to medium brown leaf spots with a raised, dark brown margin. Stromata present or absent, visible in sub-stomatal cavity, hyaline or lightly pigmented, dark brown with globose to broadly ellipsoidal, round or elongated pseudo-parenchymatous cells when present. Colonies spreading, smooth, often covered with slimy masses of conidia, usually with sparse aerial mycelium; light brown, yellow, pink or black. Hyphae with cells commonly wider than long, hyaline, frequently soon becoming brown and thick-walled sometimes thin, smooth, transversely septate. Sexual morph: Unknown. Asexual morph: Conidiomata acervular to sporodochial, amphigenous, substomatal, subepidermal, pulvinate, dry or crystaline in appearance, pale brown, discrete. Conidiogenous cells on hyaline hyphae, lateral, terminal or intercalary, cylindrical, clavate or globose, integrated, terminal, with holoblastic, polyblastic conidiogenesis, with numerous synchronously produced conidia. Conidia blastic, hyaline to dark brown, smooth-walled, aseptate, straight, ellipsoidal to spherical, reniform to sickle-shaped, sometimes cylindrical with obtuse ends and occasionally with a slightly truncate base, rather variable in shape and size. Secondary conidia common; endoconidia often present. Occasionally dark, one or two celled arthroconidia are formed. Hyaline conidia one-celled, smooth, ellipsoidal, very variable in shape and size often with an indistinct hilum. Dark brown conidia 1–2-celled, 2- celled slightly constricted at septum (adapted from Hyde et al. 2013).
Type species: Aureobasidium pullulans (de Bary & Löwenthal) G. Arnaud
Notes: Aureobasidium is characterised by amphigenous, necrotic, sunken leaf spots, hyaline or lightly pigmented stromata, acervular or sporodochial, amphigenous conidiomata, cylindrical, clavate or globose conidiogenous cells, blastic, hyaline to dark brown conidia. The type specimen Aureobasidium vitis is lost. Arnaud (1910) considered Dematium pullulans and Aureobasidium vitis as the same species. Hermanides-Nijhof (1977) designated CBS 584.75 as the ex-neotype strain of A. pullulans and considered the latter as the oldest name for the type species of Aureobasidium. Thambugala et al. (2014) introduced Aureobasidiaceae to accommodate Aureobasidium. Aureobasidium is morphologically and phylogenetically a distinct genus in Aureobasidiaceae. However, Aureobasidiaceae had already been introduced by Ciferri (1958) and should be synonymized under Saccotheciaceae as the latter is the oldest name (Hongsanan et al. 2020). Thus, the genus Aureobasidium is currently placed in Saccotheciaceae. Molecular markers available for Aureobasidium are ITS, LSU, SSU, BTUB and TEF.