First report of heart rot of pomegranate (Punica granatum) caused by Alternaria alternata in Italy.
In the provinces of Catania and Syracuse (eastern Sicily, Italy), in September and October 2013 and 2014, in several commercial orchards of pomegranate cv. 'Wonderful', a fruit disease with an incidence of 1 to 9% was observed. The symptoms consisted of a black rot of arils, which spreads from the calyx area, sometimes confined to part of fruit compartments, while the rind remained unaffected. When fruit was cut open, a dark gray to black mold emerged. Affected mature fruit were lighter in weight but remained firm and attached to the tree canopy. The only external symptom was an asymmetrical shape and a dark colored area of rind corresponding to the interior rot. Based on morphological characteristics, molecular analysis (sequence analysis of the ITS-rDNA and partial TEF1-alpha regions) and pathogenicity tests, the causal agent was identified as Alternaria alternata. The hearth rot of pomegranate, also known as black rot, was reported in other major pomegranate-producing countries, such as Greece, Israel and California. This is thought to be the first report of heart rot in Italy.