The frequency of reassortants and recombinants in progenies from double inoculations with CMV isolates belonging to subgroups IA (genetic type AAA.A, i.e., allele A at loci i, j, k1, and k2, ORFs 1a, 2a, 3a, and CP, respectively; see Materials and Methods) and IB (genetic type BBB.B, i.e., allele B at the four loci) was analyzed in Chenopodium quinoa, a local-lesion host for CMV, and in tobacco, a host in which CMV infection is systemic. Here, CP is linked to cytomegalovirus infection.