CHARACTERIZATION AND DETECTION OF GRAPEVINE FANLEAF VIRUS BY USING CDNA PROBES

Complementary DNA copies to the RNAs of grapevine fanleaf virus (GFLV) strain F13 were cloned in Escherichia coli plasmid pUC9 and used after nick-translation labeling as probes to detect and to characterize several GFLV isolates by molecular hybridization. Picogram amounts of viral RNA were detected specifically in RNAs extracted from plants with P-32 probes. Cross-hybridizations indicating nucleotide sequence homologies were obtained between GFLV probes and RNAs from arabis mosaic virus (ArMV). When a probe specific to the GFLV-F13 satellite RNA was used, it was possible to reveal the presence of satellite RNA associated with different GFLV and ArMV isolates, thus indicating strong homologies between these large satellite RNAs. The probes were also successful for viral detection directly on grapevine extracts. The RNA patterns obtained after northern hybridization were identical in grapevine leaves and rootlets.