First Report on the Occurrence of Grapevine leafroll-associated virus 5 in Chilean Grapevines

Abstract

Grapevine leafroll is one of the most widespread and economically damaging viral diseases of grapevines. At least eight distinct Grapevine leafroll-associated viruses (GLRaVs), all members of the Closteroviridae family, have been associated with this disease (4). GLRaV-5 was recently reported in vineyards from Argentina (2). To determine if GLRaV-5 was present in Chilean grapevines, in addition to the previously reported GLRaV-1, -2, -3, -4, -7, and -9 (1), 45 dormant cane samples from 12 different cultivars were collected from different geographic regions of Chile and screened by reverse transcription-PCR. Two of the forty-five samples (cvs. Sauvignon Blanc and Superior) collected from the III (700 km north of Santiago) and VI (150 km south of Santiago) regions of Chile, respectively, were found to be infected with GLRaV-5 using two different pairs of virus-specific primers. The first pair of primers, LR5-1F: 5'-CCCGTGATACAAGGTAGGACA-3' and LR5-1R: 5'-CAGACTTCACCTCCTGTTAC-3' (3), was used to amplify a 690-bp fragment corresponding to a partial region of the coat protein gene. The sequences obtained from the two positive samples (GenBank Accession Nos. HM214148 and HM214149) shared 97 and 94% of nucleotide identities, respectively, with the corresponding fragment of a reference GLRaV-5 isolate (GenBank Accession No. EU815935). Both samples shared 99% of amino acid identity with the same reference isolate. A second pair of primers, LR5upF: 5'-CTCTGCTTTTCTGCTGGCA-3' and LR5doR: 5'-TATCTTTTATCTCCCGATAAACGAG-3' (4) that amplified a 160-bp fragment of the HSP70h gene was also used. The positive Chilean samples (GenBank Accession Nos. HM214150 and HM214151) shared in both cases 98% nucleotide and 98% amino acid identities with the corresponding fragment of a reference GLRaV-5 isolate (Accession No. AF039552). The two GLRaV-5-positive plants were additionally infected with other viruses previously reported in Chile (1). The cv. Sauvignon Blanc sample was also infected with GLRaV-2, Grapevine fleck virus, and Grapevine rupestris stem pitting-associated virus. The cv. Superior sample was also infected with GLRaV-3, GLRaV-4, and Grapevine virus A.