Mixed infection by Pepino mosaic virus and Tomato chlorosis virus in protected tomato crops in Sicily

An unusual virus-like yellow leaf disorder associated with fruit marbling was observed during the winterof 2005 in some greenhouse tomato crops in the province of Ragusa Sicily (Southern Italy). Leaf samples from 250symptomatic tomato plants were serologically tested by DAS-ELISA technique for 5 viruses: Tomato spotted wiltvirus (TSWV), Impatiens necrotic spot virus (INSV), Tobacco mosaic virus (TMV), Cucumber mosaic virus (CMV)and Pepino mosaic virus (PepMV). PepMV was detected in 215 of the samples. The virus was mechanically transmitted to cucumber, wild metel, wild tobacco and ‘Rio Grande’ tomato. The experimental host range of PepMV-Ragusa differed from that of the PepMV found in Sardinia in 2001, which infected ‘Camone’ tomato. By applying RT-PCRto 25 PepMV-infected tomato plants, the expected 844 bp DNA fragment for PepMV and the expected 439 bp DNAfragment for Tomato chlororis virus (ToCV) were obtained from all the samples tested. Sequences of the obtainedamplicons were used to study the phylogenetic relationships of the viruses with isolates from other countries. Nucleotidesequence alignments showed that the sequence CP-PepMV-Ragusa (Genbank acc. No. DQ 517884) were 99%homologous with both US2 and Spain-Murcia isolates, while those of ToCV-Ragusa (Genbank acc. No. DQ517885)isolate HSP70, were 99% homologous with the Florida isolate, and 98% with the Lebanon isolate. The results provedthat the unusual disorder found in greenhouse tomatoes in Sicily can be associated with infections by PepMV andToCV, reported for the fi rst time in a mixed infection.