Bacterial wilt, caused by Ralstonia solanacearum, on tomato in Italy.
Symptoms of wilting, resembling those incited by R. solanacearum, were observed in February and April 2007 on tomato cultivars Arawak, Ikram and Cuore di Bue grown in greenhouses in southern Sardinia, Italy. Initially, the affected plants showed collapse of the growing apex. Stunted lateral shoots emerged, then wilted and died, while adventitious roots appeared on the stems. Cross sections of stems showed brown discoloration of the vascular tissue and oozed a dirty white exudate. In April, when environmental conditions were warmer, wilting of the whole plant occurred rapidly. The percentage of wilted plants ranged from 10 to 70%. The morphological and biochemical characterization of the isolates, followed by pathogenicity and PCR tests revealed that the causative organism was R. solanacearum type strain NCPPB 325. This is thought to be the first report of the presence of R. solanacearum on tomato in Italy.