Diversity of Grapevine fanleaf virus isolates from Iran

Enzyme-linked immunosorbent assay (ELISA) testing of 126 grapevine samples, from vineyards in the northwest region of Iran, detected Grapevine fanleaf virus (GFLV) in 33 samples. Total RNA from eight of the infected samples were subjected to reverse transcription polymerase chain reaction (RT-PCR) analysis using primers which corresponded to the virus coat protein and 3′ non coding region of RNA 2. An expected 1620 bp DNA fragment was amplified from all the tested samples. PCR products from isolates B5, S1 and SH3 were cloned and the nucleotide sequences of three clones from each isolate were determined. The sequences showed that a DNA fragment of 1623 bp from isolate S1 and 1629 bp from isolates B5 and SH3 were amplified. The fragments covered 1481 nucleotides of the 3′ proximal region of the CP gene plus 142 or 148 nucleotides of the 3′ non coding region. Alignment of the sequences revealed over 99% identities among clones from each isolate and 83–93% among clones from different isolates. Identities of 83–94% were found between the isolates from Iran and previously reported GFLV strains/isolates. Phylogenetic analysis based on CP sequences showed that isolates S1 and SH3 formed a distinct cluster but isolate B5 clustered with previously reported GFLV strains. This is the first report on sequence analysis of nearly full-length CP cDNA clones of GFLV isolates from Iran.