Rapid Diagnosis of Potato Leaf Roll Virus by Immune Electron Microscopy

Abstract

Immune electron microscopic (IEM) methods were successfully applied to a rapid diagnosis of potato leaf roll virus (PLRV). PLRV particles were easily detected as specific virus clumping when the clarified, unconcentrated preparations obtained from diseased young potato sprouts and the PLRV antiserum were mixed and incubated overnight in a cold room (clumping method). In addition, support films covered with PLRV antiserum in advance efficiently trapped PLRV particles (modified Derrick method). Futhermore, the individual particles were accurately detectable by the increase of their size with due to a specific halo, when the procedure (modified Derrick method) was followed by decoration with either antiserum or the purified IgG (immunoglobulin G) component. As the diagnosis of PLRV can be made within a few days, this method will be applicable to routine indexing for PLRV for inspection programs.