Citrus exocortis viroid infecting twenty year old Solanum jasminoides plants in Italy.

Abstract

Potato spindle tuber viroid (PSTVd), the type species of the genus Pospiviroid, and other members of the same genus, including Citrus exocortis viroid (CEVd), have been found in symptomless ornamental solanaceous plants, which may serve as potential inoculum for susceptible horticultural crops, as shown in Italy by a recent PSTVd outbreak in tomato (Navarro et al., 2009). We have recently identified CEVd in Solanum jasminoides in Apulia (southern Italy), an ornamental species in which this viroid is widely distributed, especially in the nurseries (Torchetti et al., 2011). Here we report the identification of CEVd in a more than 20-year-old S. jasminoides plant from Latium (central Italy). The viroid was first detected by RT-PCR using generic primers for pospiviroids (Bostan et al., 2004); then, it was identified by RT-PCR using CEVd-specific primers (Torchetti et al., 2011) followed by cDNA sequencing. The amplicon had a sequence 97-98% identical to CEVd variants previously reported from S. jasminoides in other countries (GenBank accession Nos AM920649; GU300810; HQ423166). Tested samples were collected in a private garden located in a very isolated area, in which no other potential natural CEVd inoculum (i.e. Citrus spp.) were found, supporting the possibility that the S. jasminoides plants were already infected when transplanted. This finding dates back by at least twenty years the presence of CEVd infection of S. jasminoides in Italy.