First report of Grapevine Pinot gris virus in Georgia

Grapevine Pinot gris virus (GPGV), a Thricovirus (Betaflexiviridae) inducing grapevine mottling and deformation in Vitis vinifera L., has been reported in Europe and Korea (Martelli, 2014). During autumn 2013, a survey on the sanitary status of native V. vinifera cultivars was carried out in Georgia, collecting leaf samples from 37 vines of 25 white- and red-berried cultivars. To detect GPGV, total RNAs were extracted from leaf tissues and RT-PCR reactions were performed with specific primer pairs amplifying distinct genomic regions (GPG-14F/GPG-632R, GPG-5637F/GPG-5939R, GPG-6609F/GPG-7020R, DetF/DetR) (Glasa et al., 2014; Morelli et al., 2014). DetF/DetR PCR products were sequenced (coverage 4X) and compared with GenBank sequences. Phylogenetic analysis was done using the software MEGA6. GPGV was detected in eight plants of white-berried cvs Goruli mtsvane, Khikvi, Mtsvane kviteli and red-berried cvs Saperavi pachkha, Tavkveri, Korkaula using primer pairs GPG-5637F/GPG-5939R and DetF/DetR. GPGV detection sensitiveness of the other primer pairs was lower. Blast comparison with GenBank showed that the Georgian GPGV isolates share the highest sequence identity at the nucleotide level (98%) with the isolate GPGV SK107 from Slovakia (GenBank accession No. KF134126). Phylogenetic analysis performed by MEGA6 showed that the Georgian GPGV isolates grouped with the Slovakian isolates in a distinct cluster separated from the Italian, French, and Slovenian isolates. To our knowledge, this is the first report of GPGV in Georgia. As response of Georgian grapevine varieties to pathogens has not been described accurately, further investigation will be crucial to determine the symptoms associated with GPGV presence and to evaluate its potential effects on yield and wine quality.