Characterization of Cucumber mosaic cucumovirus associated with banana mosaic disease by combined approaches

12 Cucumber mosaic virus (CMV) isolates associated with banana mosaic disease (BMD) in Taiwan were collected and characterized. From the symptoms induced on banana by these CMV isolates, three symptom types were grouped. Members within each banana symptom type also induced similar symptoms on N. glutinosa. It suggested that members within each banana symptom type do share similar common biological prosperities in inducing symptoms on banana and N. glutinosa. Double stranded RNA analysis revealed that the differential symptoms between groups are not related to the presence of satellite RNA. On the contrary, although cowpea is good hosts in CMV grouping based on the ability of CMV in cowpea systemic infection, the grouping is irrelevant in banana symptom inducing. Sequence analysis revealed that the systemic infection of CMV in cowpea reflected in their CP sequence. Phylogenetic analysis also revealed that CMV associated with BMD did not cluster together and were randomly assigned into distinctive CMV subgroup. It indicated several distinctive CMV strains all have the ability to infect banana which will complicate the disease managements. Interestingly, phylogenetic analysis using 89 CMV reported around the world reveled that in contrast to the currently known CMV subgroup IA , IB and II, our collected CMV form a new subgroup within subgroup I, and two new distinctive CMV subgroups within subgroup I were also resolved. Our analysis also pointing out that subgroup IB of CMV is actually phylogeneticlly unresolved and grouping of CMV may need to be further improved.