DETECTION OF POTATO LEAFROLL VIRUS IN LEAF AND APHID EXTRACTS BY DOT-BLOT HYBRIDIZATION

Cloned cDNA to potato leafroll virus (PLRV) RNA was evaluated for dete ction of PLRV in virus-infected samples from four states and the count ries of Colombia and Russia. The use of formaldehyde was 32 times more effective than formamide for denaturing leaf tissue extracts in the d ot-blot assay, and the sensitivity of the technique was estimated to e qual that of the enzyme-linked immunosorbent assay (ELISA) for PLRV de tection. These results, use of a commercial leaf sap extractor, detect ion of virus in bulk aphid samples, and use of the assay in a nonradio active format demonstrate that the technology has potential for large- scale disease screening programs.