Characterization of a Carlavirus Isolated from Aster novae-angliae. L. W. Stobbs, Agriculture Canada, Research Station, Vineland Station, Ontario L0R 2E0. J. G. Van Schagen, Agriculture Canada, Research Station, Vineland Station, Ontario L0R 2E0. Plant Dis. 75:421-424. Accepted for publication 5 November 1990. Copyright 1991 Department of Agriculture, Government of Canada. DOI: 10.1094/PD-75-0421.

A previously unidentified carlavirus was isolated from Aster novae-angliae near Jordan Station, Ontario, and was found in one commercial greenhouse containing cultivars of Aster spp. Infected plants were stunted and showed systemic chlorosis and rosetting. Apical leaves were distorted, often showing necrotic flecking. The virus was readily transmitted mechanically and by several aphid species between Aster and Chenopodium spp. but was not seedborne. On the basis of host range studies, no similarity could be found between the virus and other viruses described in Aster spp. or within the carlavirus group. No serological relatedness was evident between the virus and several viruses described in the potexvirus, carlavirus, or potyvirus group. Physiochemical properties were similar to those of other carlaviruses. The virus was a single sedimenting nucleoprotein (590–640 nm long and 13 mm in diameter) with a buoyant density in sucrose of 1.29 g/cm³, a sedimentation coefficient of 160 S, an ultraviolet extinction coefficient of 2.4, and an A_259/280 ratio of 1.38. Polyacrylamide gel electrophoresis revealed one protein species with an M_r of 35,400 daltons and RNA with an M_r of 2.78 × 10⁶ daltons. The hyperchromic profile indicated a single-stranded RNA.