Presence and molecular characterization of cucumber mosaic virus on safflower in Serbia

Safflower (Carthamus tinctorius L.) is an important oilseed crop belonging to the family Asteraceae. A total of 46 safflower samples were collected from Srbobran locality (South Bačka District) in Serbia in 2015 and analysed for the presence of cucumber mosaic virus (CMV), alfalfa mosaic virus (AMV), and lettuce mosaic virus (LMV), using commercial double-antibody sandwich (DAS)-ELISA kits. Both viruses, CMV and AMV, were detected serologically in the collected samples. None of the analysed samples was found to be positive for LMV. The presence of CMV was further confirmed by mechanical transmission to test the plants including Chenopodium quinoa, C. amaranticolor, Nicotiana glutinosa, and Datura stramonium as well as C. tinctorius, confirming the infectious nature of the disease. Molecular detection of CMV was performed by amplification of a 871 bp fragment in all the tested samples, using the specific primers CMVCPfwd/CMVCPrev that amplify the entire coat protein (CP) gene and part of 3'and 5'-UTRs of CMV RNA 3. The RT-PCR products derived from the isolates 290Saff and 294Saff were sequenced (MH577791 and MH577792, respectively) and compared with the CMV sequences available in GenBank. Phylogenetic analysis based on CP gene sequences showed clustering of the selected isolates into three subgroups: IA, IB and II. Serbian CMV isolates found in safflower belong to subgroup II. To our knowledge, this is the first report on CMV infection of safflower in Serbia, which has the potential to cause substantial damage to safflower production and pose a threat to other economic crops grown in Serbia.