A previous report (1) drew attention to the occurrence in the U.S. of tobacco rattle tobravirus (TRV) in several perennial ornamentals that move freely in international trade. Here we report the occurrence of TRV in an additional host plant of this type. The virus was identified in anemone (Anemone × hybrida cv. Honorine Jobert) with leaf symptoms consisting of chlorotic blotches, chlorotic line patterns, and distortion. Characteristic tobravirus-like particles with modal lengths of 50, 80, 130, and 180 nm were observed by electron microscopy in partially purified extracts of symptomatic but not of asymptomatic plants. These particles reacted specifically with antibodies to TRV and pea early-browning (PEBV) tobraviruses in immunoelectron microscopic (IEM) assays, produced typical TRV-induced symptoms in Nicotiana benthamiana and N. clevelandii, in which similar particles were detected by IEM, but, like other TRV isolates, did not infect pea (2). No other viruslike particles were observed in partially purified extracts of symptomatic anemone plants. This is the first report of TRV infection in anemone. While TRV occurs widely in Europe, it had been identified previously in the U.S. only in Oregon, Washington, and California (1,2,3). This virus is an important pathogen of several crops, including potato. Several areas of the Midwest, including Minnesota and Wisconsin, have significant seed-potato industries, and further introduction and possible dissemination of TRV pose potential regulatory and quarantine issues. This example of the movement of an exotic pathogen of potential economic importance into new areas underlines the need for closer monitoring of plant material entering international trade in an era of increasing globalization.
References: (1) B. E. Lockhart et al. Plant Dis. 79:1249, 1995. (2) B. E. L. Lockhart and H. U. Fischer. Phytopathology 66:1391, 1976. (3) J. M. Crosslin and P. E. Thomas. Am. Potato J. 72:605, 1995.