Dicentra, Epimedium, and Heuchera: New Perennial Ornamental Hosts of Tobacco rattle virus in the United States.

Yellow ringspotting and concentric line patterns in plants of Dicentra (bleeding heart), Epimedium (barrenwort), and Heuchera (coral bells) from commercial nurseries and home gardens in Minnesota, Michigan, and Massachusetts were associated with infection by Tobacco rattle virus (TRV), which was identified by particle morphology, enzyme-linked immunosorbent assay and immunosorbent electron microscopy. No other viruslike particles were observed by electron microscopy in partially purified preparations of TRV-infected leaf tissue, and TRV was not detected in asymptomatic plants. This is the first report of TRV occurrence in Dicentra in the United States and the first report of TRV occurrence in Epimedium and Heuchera. In previous reports (1,2) we have called attention to the increasing incidence of TRV in vegetatively propagated perennial ornamental plant species in the United States and to the potential for virus spread to crops such as potato, in which TRV has not been reported in the midwestern United States. It is possible that increased international trade in vegetatively propagated ornamental plants may be resulting in the introduction of TRV and other exotic viruses into the United States and elsewhere. It is also possible that the natural occurrence of TRV in North America may be actually more widespread than has been reported. References: (1) B. E. Lockhart et al. Plant Dis. 79:1249, 1995. (2) B. E. Lockhart and J. A. Westendorp. Plant Dis. 82:712, 1998.