Archivio Journal of Plant Pathology

Abstract:

A survey to assess the presence and incidence of Grapevine virus E (GVE) in China was carried out in 2011 and 2012 by testing dormant canes of 192 grapevine samples collected from the Chinese provinces of Liaoning (183 samples), Xinjiang (8 samples), and Jilin (1 sample). Total RNA was extracted from cortical scrapings according to Foissac et al., (2001) and submitted to RT-PCR using GVE-specific primers designed on the viral movement protein (GVE-MP1 5’-TGTGGGGTGCATAGTCATAGGTTT-3’ and GVE-MP2 5’-GCTTTTGACTCCATTGGCTTTCTC-3’) and coat protein (GVE-CP1 5’-GTGGGTGAACCACTCAAGGT-3’ and GVE-CP2 5’-AGACCACTTGCGGCTCTTTA-3’) genes. Ten of 192 tested samples (5.2%) resulted positive with both primer sets. Considering that Grapevine virus A and B (GVA and GVB) infected 4.7% and 1.6% of the samples, respectively, GVE resulted the most common vitivirus in our survey. The 992-bp and 478-bp long PCR products amplified from a Chinese table grape cultivar (Guifeimeigui) were cloned and sequenced. These sequences comprised the complete CP and putative nucleic acid binding protein genes, as well as the partial sequence of the MP gene. Comparisons with GenBank sequences revealed 99% identity of thie Chinese GVE isolate (GenBank accession No. JX570675 and JX570674) with the South African strain (GU903012). Further molecular analysis revealed that all GVE-infected vines hosted also one or two other viruses, including Grapevine leafroll associated virus -1, -2, -3 and Grapevine rupestris stem pitting associated virus (GRSPaV). The presence of mixed infections did not allow to establish a direct relationship between GVE and disease symptoms, except for an observed aggravation of leafroll symptoms, that needs further studies. To the best of our knowledge, this is the first report of GVE in China.