The detection of CaMV recombinants in turnip hosts has been reported numerous times. Some studies have demonstrated the appearance of infectious recombinant viral genomes after inoculation (i) of a host plant with two infectious or non-infectious parental clones [21, 32, 33, 34, 35] or (ii) of a transgenic plant containing one CaMV transgene with a CaMV genome missing the corresponding genomic region [36] . While the former revealed inter-genomic viral recombination, the latter demonstrated that CaMV can also recombine with transgenes within the host's genome. Another study based on phylogenetic analyses of various CaMV strains has clearly suggested different origins for different genomic regions and, hence, multiple recombination events during the evolution of this virus [37] . Indirect experimental evidence has indicated that, in some cases, CaMV recombination could occur within the host nucleus, between different viral minichromosomes, presumably through the action of the DNA repair cellular machinery [21, 35] . Nevertheless, the mechanism of ''template switching'' during reverse transcription, predominant in all retroviruses, most certainly also applies to pararetroviruses. For this reason, and on the basis of numerous experimental data, CaMV is generally believed to recombine mostly in the cytoplasm of the host cell, by ''legal'' template switching between two pre-genomic RNA molecules [21, 35, 36, 38, 39] , or ''illegal'' template switching between the 19S and the 35S RNA [36, 40] . Under this hypothesis, recombination in CaMV could therefore be considered as operating on a linear template during reverse transcription, with the 59 and 39 extremities later ligated to circularize the genomic DNA (position 0 in Figure 1 ). The above cited studies clearly demonstrate that CaMV is able to recombine. However, since these studies are based on complementation techniques, non-quantitative detection, or phylogenetically based inferences of recombination, they do not inform us on whether recombination is an exceptional event or an ''everyday'' process shaping the genetic composition of CaMV populations.