Archivio Journal of Plant Pathology

Abstract:

During the last three years a survey was made to evaluate the presence and distribution of citrus viroids in the Campania region (Southern Italy). A total of 112 citrus trees of different species and cultivars were inspected visually and sampled. One hundred and four out of the 112 samples graft-inoculated into Arizona 861-S1 “Etrog” citron gave typical viroid symptoms. Viroid infection was confirmed by sequential polyacrylamide gel electrophoresis (sPAGE) analysis and molecular hybridization of imprinted membranes. Hop stunt viroid (HSVd), Citrus viroid III (CVd-III) and Citrus exocortis viroid (CEVd) were the most widely detected, accounting respectively for 87, 85 and 68% of the tested sources. Citrus viroid IV (CVd-IV) and Citrus bent leaf viroid (CBLVd), never reported in Italy before, were found in 24 and 13% of the sources. Most of the trees (82%) were infected with more than a viroid. The most frequent viroid combinations were CEVd + HSVd + CVd-III (43%), HSVd + CVd-III (17%) and CEVd + CBLVd + HSVd + CVd-III + CVd-IV (13%).