Relationship of Potato Leafroll Virus to Luteoviruses: Evidence from Electron Microscope Serological Tests

Abstract
Summary In immunosorbent electron microscopy tests, large numbers of particles of a Scottish isolate of potato leafroll virus (PLRV) became attached to grids coated with antisera prepared to Canadian, Japanese or Swiss isolates of PLRV. Moderate numbers of particles became attached using antiserum to tobacco necrotic dwarf virus or to bean leafroll virus, smaller numbers using antiserum to soybean dwarf virus or to barley yellow dwarf virus (RPV strain) and a few particles became attached using antiserum to barley yellow dwarf virus (MAV strain) or to beet western yellows virus. A similar pattern of antigenic relationships was deduced from tests in which the binding of antibody molecules to PLRV particles exposed to different concentrations of the antisera was assessed by electron microscopy. It is concluded that these viruses should all be included in the luteovirus group and that their apparent degree of relationship to PLRV is: tobacco necrotic dwarf virus > bean leafroll virus > soybean dwarf virus > barley yellow dwarf virus (RPV strain) > barley yellow dwarf virus (MAV strain).