Molecular characterization of a Strawberry mild yellow edge virus isolate from Canada

Over the past several years, strawberry production in Canada and the United States has been severely affected by strawberry acute decline symptoms. The decline disease is apparently caused by synergistic infections of several viruses, including Strawberry mild yellow edge virus (SMYEV) and Strawberry mottle virus (SMoV). To better understand the causal viral pathogens, we cloned and sequenced the entire genome of a SMYEV isolate, AB5-2, from a strawberry field in Prince Edward Island. The viral genome of AB5-2 consists of 5969 nucleotides excluding the 3 terminal poly(A) tail. Searches of the NCBI database identified two SMYEV isolates (MY-18 from the USA and D74 from Germany) whose complete genome sequences were documented and 28 SMYEV isolates with determined coat protein (CP) sequences. At the genome level, the Canadian SMYEV isolate shares 86% and 90% nucleotide sequence identities to MY-18 and D74, respectively. Phylogenetic analysis of all CP sequences available clustered 28 SMYEV isolates into five phylogroups, including AB5-2 alone as a new group, suggesting this Canadian isolate is distinct from SMYEV isolates of other origins. This report represents the first molecular characterization of a SMYEV isolate from Canada.