Tobacco mild green mosaic virus (TMGMV) isolates from different plant families show no evidence of differential adaptation to their host of origin. tobacco mild green mosaic virus (TMGMV)

We obtained TMGMV isolates from non-solaneceous hosts and we tested the capacity of genetically closely-related TMGMV isolates from three host families to infect and multiply in 10 hosts of 6 families. All isolates systemically infected all hosts, with clear disease symptoms apparent only in solanaceous hosts. TMGMV multiplication depended on the assayed host but not on the isolate host of origin, all isolates accumulating to highest levels in Nicotiana tabacum. Thus, results support that TMGMV isolates are adapted to hosts in the genus Nicotiana, consistent with a well-known old virus-host association. In addition, phenotypic plasticity allows Nicotiana-adapted TMGMV genotypes to infect a large range of hosts, as encountered according to plant community composition and transmission dynamics.