A MILD CHLOROSIS VIRUS OF PHYSALIS FLORIDANA FOUND IN A TURNIP LATENT VIRUS COMPLEX

Abstract

Myzus persicae (Sulz.) transmitted a new virus to healthy Physalis floridana Rydb. from other P. floridana infected with a turnip latent virus complex. Symptoms were characterized by a chlorosis and sometimes cupping of only the lower leaves with slight stunting of plants. These symptoms could easily be mistaken for those incited by potato leaf roll virus but they were strikingly different from the yellow netting of plants infected with the turnip latent virus complex.In virus–vector studies with the new virus and M. persicae, an occasional aphid acquired the virus in 2 hours and 14% of infective insects transmitted it in 30 minutes. When acquisition and inoculation feedings were each increased to 48 hours, transmissions by single aphids of 70% and more were common. A few aphids transmitted the virus in a total transmission time of 30 hours, but most required 72 hours or longer to acquire, become infective, and transmit it.In comparative tests between the new virus and either potato leaf roll or the turnip latent complex, the new virus and potato leaf roll were recovered from plants 3 days after inoculation but the complex was not recovered for 14 days or longer. Of five aphid species tested, M. persicae was an efficient vector of all three viruses and the only species to transmit the new virus and the turnip latent complex. Plants infected with the new virus and showing symptoms were as easily infected with potato leaf roll as were comparable controls, but fewer of them became infected with the complex. The new virus and the complex were quite similar in host range, and susceptible plants were found in the Amaranthaceae, Chenopodiaceae, Cruciferae, and Solanaceae.The new virus is called mild chlorosis virus of P. floridana.