Authors
P. F.
Escobar
,
Fundación Ciencia para la Vida and MIFAB, Zañartu 1482, Santiago, Chile
;
N.
Fiore
,
Facultad de Ciencias Agronómicas, Universidad de Chile, Santa Rosa 11315, Santiago, Chile
;
P. D. T.
Valenzuela
,
Fundación Ciencia para la Vida and MIFAB, Zañartu 1482 and Universidad Andrés Bello, República 217, Santiago, Chile
; and
E. A.
Engel
,
Fundación Ciencia para la Vida and MIFAB, Zañartu 1482 and Universidad Andrés Bello and MECESUP(2), República 217, Santiago, Chile
Grapevine leafroll is one of the most widespread and economically relevant viral diseases of grapevines. At least nine distinct Grapevine leafroll-associated viruses (GLRaVs), all members of the Closteroviridae family, have been associated with this disease in grapevine. Grapevine leafroll-associated virus 4 (GLRaV-4), currently classified as a Closteroviridae member under the Ampelovirus genus, was initially described in California. To determine if GLRaV-4 was present in Chilean grapevines, in addition to the previously reported GLRaV-1, -2, -3, -7, and -9 (1,2), 35 dormant cane samples from 12 different cultivars were collected from different regions of Chile and screened by reverse transcription-PCR. Two of the 35 samples (both cv. Thompson Seedless) collected from the III and VI regions of Chile were found to be infected with GLRaV-4 using two different pairs of GLRaV-4 specific primers. The first pair of primers, HSPV-F: 5′- ACA TTC TCC ACC TTG TGC TTT T -3′ and HSPC-R: 5′- CAT ACA AGC GAG TGC AAT TAC -3′ (3), was used to amplify a 321-bp fragment corresponding to a partial region of the HSP70h gene. The sequence (GenBank Accession Nos. EU746618 and EU746619) from both positive samples shared 98.4% nucleotide identity and approximately 99% identity with the corresponding fragment of a Californian GLRaV-4 isolate (GenBank Accession No. AF039553). Since there are no commercial antibodies available for GLRaV-4 detection, a second pair of primers, LR4CPINT-F: 5′- GAG AGT GAC AAG CAC CAG GTG C -3′ and LR4CPFIN-R: 5′- TCA CCT CCT GTT GCC CA -3′ (4), that amplified a 492-bp fragment of the coat protein gene was also used. The sequences of the 492-bp fragment from both Chilean samples (GenBank Accession Nos. EU746620 and EU746621) shared 99.6% nucleotide identity with one another and had 96.5% identity with an Israeli GLRaV-4 isolate (GenBank Accession No. AM176759). To our knowledge, this is the first report of GLRaV-4 in Chile. Further studies will help to establish the effects and incidence of this virus in Chilean grapevines.
References: (1) E. Engel et al. Plant Dis. 92:1252, 2008 (2) N. Fiore et al. J. Plant Pathol. 90:125, 2008. (3) F. Osman et al. J. Virol. Methods 141:22, 2007. (4) P. Saldarelli et al. J. Plant Pathol. 88:203, 2006.
