From Figure 1 , and supposing that all marker-containing genomic regions can recombine, we could predict the detection and quantification of seven classes of recombinant genotypes: þbcd/aþþþ, aþcd/þbþþ, abþd/þþcþ, abcþ/þþþd, þþcd/abþþ, aþþd/þbcþ, and aþcþ/þbþd. Indeed, all classes were detected, and their frequencies in the ten CaMV populations analyzed are summarized in Table 1 .