Syringa vulgaris is a new host for Cucumber mosaic virus

Virus-like symptoms consisting of light mosaic, chlorotic spots and oak chlorotic line patterns were observed on lilac plants (Syringa vulgaris L.) growing in a public garden in Imola (Emilia Romagna region, Italy). The causal agent was identified as cucumber mosaic virus (CMV) on the basis of biological, serological and nucleotide sequence properties of partial coat protein and movement protein genes, and the isolate was designated SYV. The CMV-SYV isolate caused mosaic symptoms on indicator plants of Nicotiana tabacum cv. Xanthi-nc, N. rustica and Cucumis sativus, while symptoms of local necrotic spots or pin points were observed on inoculated leaves of Vigna unguiculata and Vicia faba. To assess genetic differences between CMV-SYV and other known CMV isolates, phylogenetic analyses were carried out using 16 nucleotide sequences of coat protein and movement protein genes, including for SYV. The CMV-SYV isolate was most related to CMV subgroup IA isolates, and had 85.1-100% nucleotide sequence similarity to subgroup I isolates. This is the first report of CMV infecting S. vulgaris.