Cucumber mosaic virus populations in Tunisian pepper crops are mainly composed of virus reassortants with resistance‐breaking properties

摘要: Cucumber mosaic virus is one of the most prevalent viruses in Tunisian pepper crops, where it has been detected 68% plants developing symptoms, making essential to characterize molecular and biological properties local CMV populations. Two hundred seventy-eight isolates collected late 1990s, 2006 2008–2010 were characterized genetically. Isolates belonging three phylogenetic subgroups (IA, IB II) detected, but surprisingly, 90% reassortants between IA IB, with two predominant haplotypes, IB-IA-IA IB-IA-IB (nomenclature according subgrouping genomic RNAs). The haplotype was present all regions surveyed, while observed only northern Tunisia. This situation unexpected, because previously thought be counterselected nature, this raises questions origin strains Tunisia widespread distribution these reassortant types. Phylogenetic studies revealed low diversity within whatever locality or year sampling. However, analysis frequencies a high genetic differentiation populations, which better explained by localities sampling than years. Geographic distances affected mainly north central When tested against polygenic resistance movement pepper, 55 57 able break resistance, indicating that would not useful for controlling fields.