Heart rot and soft rot of pomegranate fruit in southern Italy

Pomegranate (Punica granatum L.) has become a commercial fruit crop in southern Italy during the last years. In 2013, the specialized pomegranate cultivation extended over 130 ha. Leading producing regions are Apulia and Sicily, southern Italy. Two types of rot of mature pomegranate fruit have been detected in Sicily, heart rot and soft rot. Heart rot, which is also known as black rot, was found on fruit of the cultivar 'Wonderful' and consisted in an internal decay of the arils, usually confined to part of the fruit compartments, while the rind remained unaffected. The causal agent of this disease was identified as Alternaria alternata (Fr) Keissl on the basis of morphological traits as well as of sequencing of the ITS and TEF1-alpha gene regions. Soft rot was observed on mature fruit of 'Mollar de Elche' after dryness periods followed by intense rains. Several species of Alternaria, Aspergillus, Botrytis, Penicillium and Rhizopus genera were isolated from infected fruit but no one was consistently associated with the disease. By contrast, a close relationship was found between the occurrence of soft rot and the attacks of Mediterranean fly or other insects invading the mesocarp.