Arthrinium phaeospermum, Phoma cladoniicola and Ulocladium consortiale, New Olive Pathogens in Italy

In recent years, leaf necrosis and twig dieback in the olive crop have been detected in Sicily (Italy). In this article, we identify the predominant fungal species associated with symptomatic leaves and twigs, using morphological features and DNA sequencing of the internal transcribed spacer (ITS) region, as Alternaria alternata, Arthrinium phaeospermum, Phoma cladoniicola and Ulocladium consortiale. The pathogenicity of these four species was tested on olive plants cv. Biancolilla. All species were pathogenic on leaves, but only U. consortiale produced cortical lesions on twigs, thus suggesting its main role in the Olea europaea twig dieback. To our knowledge, this is the first report of A. phaeospermum, P. cladoniicola and U. consortiale as olive pathogens.