Closteroviridae: A family of plant viruses containing the largest single-stranded RNA genomes. Infections typically involve yellowing and necrosis, particularly affecting the phloem.Crinivirus: A genus of plant viruses in the family CLOSTEROVIRIDAE. Transmission is by whiteflies. Lettuce infectious yellows virus is the type species.Closterovirus: A genus of plant viruses in the family CLOSTEROVIRIDAE containing highly flexuous filaments. Some members are important pathogens of crop plants. Natural vectors include APHIDS, whiteflies, and mealybugs. The type species is Beet yellows virus.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.