Biological and molecular characterization of two Italian isolates of Colombian datura virus from Brugmansia spp

Two Italian isolates of Colombian datura virus (CDV) found in symptomatic Brugmansia sp. plants were characterized on the basis of symptomatology in plant hosts, immunosorbent electron microscopy, cytopathology and nucleotide and amino acid sequence analyses of 3' terminal 1.6 Kb of the viral genome. This portion of the genome of the two Italian CDV isolates shared high levels of nucleotide (98.6-99.5%) and amino acid (98.3-99.4%) identity with 14 CDV isolates available in GenBank, originating from different countries. These Italian isolates also showed similar symptomatology on a range of hosts as previously described for other CDV isolates. However, analysis of the cytopathology induced in Brugmansia cells based on the type of cylindrical inclusion (CI) formed, showed that both Italian isolates belonged to subdivision IV, although CDV was previously classified as a subdivision II CI Potyvirus. Overall, the results obtained confirm the hypothesis of the common origin of all CDV isolates identified in different countries, due to relatively recent domestication and multiplication of this species for ornamental purposes.