Escobar P F, Fiore N, Valenzuela P D T, Engel E A
Fundación Ciencia para la Vida and MIFAB, Zañartu 1482, Santiago, Chile.
Facultad de Ciencias Agronómicas, Universidad de Chile, Santa Rosa 11315, Santiago, Chile.
Plant Dis. 2008 Oct;92(10):1474. doi: 10.1094/PDIS-92-10-1474C.
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.
葡萄卷叶病是葡萄中分布最广且在经济上最为重要的病毒病之一。至少有9种不同的葡萄卷叶相关病毒（GLRaV），均为长线形病毒科成员，与葡萄的这种病害有关。葡萄卷叶相关病毒4（GLRaV-4），目前被归类为长线形病毒科中柔膜病毒属的成员，最初是在加利福尼亚州被描述的。为了确定智利葡萄藤中是否存在GLRaV-4，除了之前报道的GLRaV-1、-2、-3、-7和-9外，从智利不同地区采集了来自12个不同品种的35个休眠藤条样本，并通过逆转录聚合酶链反应进行筛选。使用两对不同的GLRaV-4特异性引物，发现从智利第三和第六地区采集的35个样本中有两个（均为汤普森无核品种）感染了GLRaV-4。第一对引物，HSPV-F：5'- ACA TTC TCC ACC TTG TGC TTT T -3'和HSPC-R：5'- CAT ACA AGC GAG TGC AAT TAC -3'，用于扩增对应于HSP70h基因部分区域的321 bp片段。两个阳性样本的序列（GenBank登录号EU746618和EU746619）与加利福尼亚GLRaV-4分离株（GenBank登录号AF039553）的相应片段共享98.4%的核苷酸同一性和约99%的同一性。由于没有可用于GLRaV-4检测的商业抗体，还使用了第二对引物，LR4CPINT-F：5'- GAG AGT GAC AAG CAC CAG GTG C -3'和LR4CPFIN-R：5'- TCA CCT CCT GTT GCC CA -3'，其扩增了衣壳蛋白基因的492 bp片段。来自两个智利样本的492 bp片段序列（GenBank登录号EU746620和EU746621）彼此共享99.6%的核苷酸同一性，并与以色列GLRaV-4分离株（GenBank登录号AM176759）具有96.5%的同一性。据我们所知，这是GLRaV-4在智利的首次报道。进一步的研究将有助于确定这种病毒对智利葡萄藤的影响和发生率。参考文献：（1）E. Engel等人，《植物病害》92:1252，2008年 （2）N. Fiore等人，《植物病理学杂志》90:125，2008年。（3）F. Osman等人，《病毒学方法杂志》141:22，2007年。（4）P. Saldarelli等人，《植物病理学杂志》88:203，2006年。
