First Report of Tomato chlorosis virus in Turkey

A tomato (Lycopersicon esculentum) plant showing severe interveinal leaf chlorosis with brown necrotic flecks was supplied by a commercial tomato greenhouse located in Fethiye, Mugla, Southwestern Turkey. The symptoms were similar to those described for infection of tomato by Tomato infectious chlorosis (TICV) and Tomato chlorosis (ToCV) criniviruses (Wisler et al., 1996). During a limited field survey, similar symptoms and the presence of whiteflies (Bemisia tabaci Genn. and Trialeurodes vaporariorum Westw.) as potential virus vectors were observed on tomato plants in various greenhouses in the same region, suggesting possible TCIV or ToCV infection. Leaf samples were taken from symptomatic and non-symptomatic tomato plants from four different greenhouses in the same area. Total RNA was isolated from 100 mg leaf samples from eight symptomatic and one non-symptomatic tomato plants using a one step RNA isolation method (BioBasic, Markham Ontario, Canada). Samples were tested for the presence of TICV and ToCV by a previously reported method using nested RT-PCR for the detection of criniviruses (Dovas et al., 2002). A highly conserved region of the heat shock protein homolog (Hsp70h) gene was first amplified by one-step RT-PCR using HS-11 and HS-12 degenerate primers. This was followed by a nested PCR with virus-specific primers: TIC-3/TIC-4 or ToC-5/ToC-6 for TICV or ToCV, respectively. No amplification with TICV primers was observed in the non-symptomatic or symptomatic plants. Conversely, a 463 bp DNA fragment was amplified by nested PCR from all symptomatic tomato samples. No amplification was observed in the sample from the non-symptomatic plant. These results suggested that the symptomatic plants were infected with ToCV. To confirm these results, an amplicon from the nested PCR was sequenced (GenBank accession no: EU069363). The sequence of the amplicon showed 99% nt identity with the Hsp70h gene of ToCV isolates from Florida, USA (Wintermantel et al., 2005) (GenBank accession no: AY903448), confirming the diagnosis of ToCV. To our knowledge, this is the first report of ToCV in Turkey.