Any of a group of three-part plant viruses which uses single-stranded RNA to code its genome and which are spread through seeds and pollen to infect a wide range of host plants. Ilarviruses include isometric labile ringspot viruses and the tobacco streak virus group.
From the BioTech Dictionary at http://biotech.icmb.utexas.edu/. For further information see the BioTech homenode.