New Records of Canker-Causing Pathogens of Acacia spp. and Pithecellobium dulce in Southern Italy

Surveys conducted in a nursery located in eastern Sicily, southern Italy, revealed the presence of plants of Vachellia nilotica (syn. Acacia arabica), V. farnesiana (syn. A. farnesiana) and Pithecellobium dulce showing symptoms of trunk and branch canker, shoot dieback and general decline. Laboratory fungal isolation from wood tissues showed high percentage of Diaporthe-like (60–62%) and Botryosphaeriaceae-like fungi (21–85%) constantly associated with the diseased samples. Subsequent molecular characterization of recovered isolates was based on sequencing of the complete internally transcribed spacer region (ITS), the translation elongation factor 1-alpha (tef1) and the beta-tubulin (tub2) regions, followed by multi-locus phylogenetic analyses. The isolates collected from symptomatic tissues were phylogenetically characterized as Diaporthe foeniculina and Neofusicoccum parvum. Pathogenicity tests were conducted on Acacia and P. dulce plants and results showed that both species were pathogenic, being able to induce necrotic lesions on the stem. To our knowledge this is the first report worldwide of D. foeniculina and N. parvum infecting A. arabica, A. farnesiana and P. dulce.