Etiology of Botryosphaeria Panicle and Shoot Blight of Pistachio () Caused by Botryosphaeriaceae in Italy.

Pistachio () is an important crop in Italy, traditionally cultivated in Sicily (southern Italy) for several decades now. In recent years, new orchards have been planted in new areas of the island. Field surveys conducted in 2019 revealed the presence of symptomatic trees showing shoot dieback, cankers, fruit spots, and leaf lesions. Isolations from symptomatic samples consistently yielded fungal species in the Botryosphaeriaceae family. Identification of collected isolates was conducted using morphological and molecular analyses. Morphological characterization was based on conidia measurements of representative isolates and also effects of temperatures on mycelial growth was evaluated. DNA data derived from sequencing the ITS, -α, and gene regions were analyzed via phylogenetic analyses (maximum parsimony and maximum likelihood). Results of the analyses confirmed the identity of , , and . Pathogenicity tests were conducted on detached twigs and in the fields both on shoots as well as on fruit clusters using the mycelial plug technique. The inoculation experiments revealed that among the Botryosphaeriaceae species identified in this study . (occasionally detected) and . were the most aggressive based on lesion length on shoots and fruits. . was the most widespread among the orchards while can be considered a minor pathogen involved in this complex disease of pistachio. Moreover, to our knowledge, this is the first report of . in Italy.