Strawberry mild yellow edge virus (SMYEV) is a member of the genus Potexvirus, family Alphaflexiviridae. It is one of the most common pathogenic viruses infecting cultivated strawberries worldwide. In this study, we investigated the genetic diversity of SMYEV in strawberry fields that were severely affected by strawberry decline disease in the eastern Canadian provinces of New Brunswick, Nova Scotia, Prince Edward Island and Quebec. A total of 134 SMYEV coat protein (CP) gene sequences, representing 85 nucleic acid haplotypes, were identified in 56 field samples. A highly divergent SMYEV population was found in all four provinces, but there was little genetic differentiation among the populations, and moreover, the Canadian SMYEV isolates formed a unique dissimilar, genetically divergent population group when compared to those reported in other countries. Phylogenetic analysis revealed three new SMYEV subclades that consisted mainly of Canadian variants and were composed of 76 sequence haplotypes (76/85, 88%). Mixed infections by different SMYEV variants were observed in 38 samples (38/56, 68%). Evolutionary analysis suggested that the SMYEV strains in eastern Canada possibly originated outside of Canada but adapted to conditions in the region through genetic mutations.

中文翻译：

---

来自加拿大东部的草莓轻度黄缘病毒的遗传多样性。

草莓轻度黄缘病毒（SMYEV）是Potexvirus属Alphaflexiviridae家族的成员。它是感染全世界栽培草莓的最常见的致病病毒之一。在这项研究中，我们调查了加拿大东部新不伦瑞克省，新斯科舍省，爱德华王子岛省和魁北克省草莓减产病严重影响的草莓田SMYEV的遗传多样性。在56个田间样品中共鉴定出134个SMYEV外壳蛋白（CP）基因序列，代表85个核酸单倍型。在所有四个省中均发现了高度不同的SMYEV种群，但这些种群之间几乎没有遗传分化，此外，加拿大的SMYEV分离株形成了独特的异种，与其他国家/地区报告的人群相比，在基因上存在分歧的人群。系统发育分析揭示了三个新的SMYEV小节，这些小节主要由加拿大变体组成，由76个序列单倍型组成（76 / 85，88％）。在38个样本中观察到了不同SMYEV变体的混合感染（38 / 56，68％）。进化分析表明，加拿大东部的SMYEV菌株可能起源于加拿大境外，但通过遗传突变适应了该地区的条件。