ABSTRACT

Gemini virases were organized into the gemini virus group; these viruses have been divided into subgroups A and B. Subgroup A contains four members as well as three probable members transmitted by leafhoppers and one probable member, beet pseudo curly top virus, transmitted by treehoppers. Thin-sectioned inclusions consisting of fibrous rings and of aggregated virus particles in nuclei of predominantly phloem cells were proposed as a diagnostic for infections by whitefly-borne geminiviruses by Kim and Carr. In light microscope studies, several geminiviruses have been shown to induce nuclear inclusions predominantly in phloem cells, which are diagnostic for infection at the group level. Abutilon mosaic virus (AbMV) was not included in the geminivirus group by Goodman, Francki and co-workers, or Matthews. Virus aggregates forming large nuclear inclusions induced by AbMV are a main characteristic of the geminivirus group.