Host range, transmissibility, and agent identification. D-437 virus was propagated in N. tabacum cv. Poppies initially exhibited strong chlorotic mosaic followed by systemic necrosis and death. Purified virions, from which a high titer polyclonal antiserum was produced in rabbits, retained the virulence of the original virus extracts toward opium poppy. Virions were disrupted with mild detergent, RNA purified, and cDNA clones are being prepared for sequencing the 3' untranslated portion of the genome.
Attempts are underway to obtain an aphid-transmitted isolate of the virus.
Positive hosts included C. album, C. amaranticolor, C. foetidum, C. murale, C. quinoa, Amaranthus sp., and spinach. No transmission occurred with Toxoptera citricidus, Aphis gossypii, Myzus nicotianae, M. persicae, and Aulacorthum solani from either a non-persistent or persistent mode. An infectious agent was isolated from velvet leaf from China. The agent was readily mechanically transmissible in several buffers but no arthropod vector was found. Hosts include cucumbers, jimson weed, New Zealand spinach, C. quinoa, C. amaranticolor, tobacco, and velvet leaf.