Characterization and pathogenicity of Pleurostoma richardsiae causing decline of mango trees in Southern Italy

Mango trees (Mangifera indica) showing symptoms of twig and branch dieback, internal wood necroses, and decline, were surveyed in an orchard in Palermo province (Eastern Sicily, Italy). A Pleurostoma-like fungus was consistently isolated from symptomatic wood tissues. Based on morphology and phylogenetic analysis of ITS and tub2 sequences, the fungus was identified as Pleurostoma richardsiae. A pathogenicity test was conducted by inoculating stems of 2-year-old mango seedlings with mycelium plugs and conidium suspensions of a representative isolate. Two months after inoculation, necrotic lesions were observed around the inoculation points, and P. richardsiae was reisolated from the necrotic tissues. This is the first report of P. richardsiae causing dieback and decline of mango trees.