Quasispecies nature of the genome of Grapevine fanleaf virus

Genetic diversity was characterized in 14 isolates of Grapevine fanleaf vir us (GFLV) recovered from grapevine (Vitis vinifera). Virions were collected by immunocapture, and a 1557 bp fragment containing part of the viral coat protein gene and part of the untranslated region to its 3' side was amplif ied by RT-PCR. Sequence variation among isolates was characterized by restr iction fragment length polymorphism (RFLP) analysis and by sequencing. The Avail-generated RFLP patterns from the various isolates were highly variabl e, The isolates were passaged in Chenopodium quinoa. The RFLP patterns alte red with passage through the alternate host, but the variation stabilized a fter a number of passages. Individual genomes were recovered by cloning. Th e subcloned sequences were found to vary from each other by as much as 13%, and the encoded amino acid sequences by as much as 9%. The data suggest th at the GFLV genome consists of quasispecies populations.