Cucumber mosaic virus Diagnosed in Desert Rose in Florida

Abstract

Desert rose (Adenium obesum (Forssk) Roem. & Schult.) is a member of the family Apocynaceae and characterized by fleshy leaves and stems and colorful flowers. This popular, exotic ornamental, originally from southeastern Africa, is propagated vegetatively and is a perennial in warm climates. Virus-like foliar symptoms, including a mosaic with dark green islands surrounding the veins and chlorosis on the leaf margins, were observed on desert rose samples from two southwest Florida nurseries in November 2002. Cucumber mosaic virus (CMV) was identified in symptomatic plants by serological testing for the presence of CMV coat protein with a commercially available ImmunoStrip test (Agdia, Elkhart, IN). A third sample expressing similar symptoms was observed in southeastern Florida in February 2003. The presence of CMV was confirmed by serological detection with a commercially available double-antibody sandwich enzyme-linked immunosorbent assay (Agdia). An agent was mechanically transmitted from the third sample to Chenopodium quinoa, resulting in the formation of chlorotic local lesions. Examination of inoculated C. quinoa leaves by double-stranded (ds) RNA analysis and electron microscopy (leaf dips) revealed the presence of a typical cucumovirus dsRNA profile and spherical virions ~28 nm in diameter, respectively, providing additional confirmation of a CMV infection. A possible satellite RNA of ~350 nucleotides was also observed by dsRNA analysis. To our knowledge, this represents the first report of CMV infection of desert rose.