Partial molecular characterization of cucumber mosaic virus isolate infecting garden peony (Paeonia officinalis) in Serbia

Paeonia officinalis (family Paeoniaceae), known as the garden peony, is a very popular flowering plant with large, showy flowers grown in many gardens in Serbia. In May 2021, peony plants showing chlorotic ringspot and severe mosaic of leaves were observed in a private garden in Zemun (District of Belgrade, Serbia). Symptomatic leaves from two plants were collected and analysed for the presence of cucumber mosaic virus (CMV), tobacco rattle virus (TRV), alfalfa mosaic virus (AMV) and tomato spotted wilt virus (TSWV) using commercial ELISA kits. CMV was detected serologically in both peony samples and no other plant virus was identified. The causal agents from both ELISA-positive samples were successfully mechanically transmissible to Chenopodium quinoa and Nicotiana glutinosa plants. CMV infection in symptomatic garden peony plants was also confirmed by RT-PCR with CMV-specific primers amplifying the complete coat protein (CP) gene and parts of the 3′- and 5′-UTRs. Selected ELISA-positive sample (318-21) was Sanger sequenced using the same primer as in RT-PCR and phylogenetic tree based on complete CP sequences showed that Serbian CMV isolate from garden peony belongs to the CMV subgroup IA.