First reports of Grapevine Pinot gris virus in the Czech Republic, Slovak Republic and Slovenia
Grapevine Pinot gris virus (Trichovirus, GPGV) is a newly described virus of grapevine which was originally identified in a grapevine plant (Vitis vinifera cv. ‘Pinot gris’) showing symptoms of chlorotic mottling and leaf deformations in the Autonomous Province of Trento, in Italy. This plant was also infected by several other viruses and viroids, and the initial studies carried out in Italy could not ascertain that the presence of GPGV was consistently associated with the observed symptoms. In addition to Italy, GPGV has also been detected in the Republic of Korea causing inner necrosis of berries and poor fruit set in cv. ‘Tamnara’ (see EPPO RS 2014/006). Two recent studies have detected the presence of GPGV in grapevine samples collected from the Czech Republic and Slovak Republic, as well as from Slovenia.
- Czech Republic and Slovak Republic
Molecular studies (small-RNA deep sequencing, RT-PCR) have confirmed the presence of GPGV in grapevine samples collected from the Czech Republic and Slovak Republic. As a result, sequences of 13 isolates of GPGV could be obtained and characterized. Among these isolates, 12 were collected from various cultivars (including cvs. ‘Alibernet’, ‘André’, ‘Dornfelder’, ‘Muller Thurgau’, ‘Veltliner’, ‘Welschriesling’) at different locations in the Slovak Republic (Čachtice, Pezinok, Topolcianky, Svaty Jur, Zelenec), and 1 GPGV isolate was collected on cv. ‘Laurot’ at Lednice in the Czech Republic. These studies showed that GPGV could be frequently detected in a relatively limited number of samples, which may suggest that this virus is common in grapevine and more widely distributed than originally thought. In addition, it was not only detected in ‘Pinot gris’ or ‘Traminer’, but in other white and red-berry cultivars. It is also pointed out that in this current work, no typical symptoms could be associated with GPGV, and all GPGV-infected Slovak and Czech grapevines were simultaneously infected by other viruses. Therefore, it is underlined that further studies are needed to understand the prevalence, geographical distribution and pathogenicity of GPGV.
- Slovenia
In vineyards of the Western part of Slovenia, unusual virus-like symptoms were first observed in 2001 on grapevine cvs. ‘Pinot gris’ and ‘Sauvignonasse’. Symptomatic plants showed shortened internodes, poor leaf development, mottling, and deformation of leaves that resulted in poor growth. During intensive visual inspections carried out from 2002 to 2006, these symptoms were observed on most grapevine cultivars grown in the Primorska region, although cvs. ‘Pinot gris’ and ‘Sauvignonasse’ remained the most commonly affected ones. Following the detection of GPGV in Italy and the Republic of Korea, its possible presence in Slovenia was studied. At 3 locations in the Primorska region, 42 leaf samples were collected mainly from symptomatic grapevine plants but also from asymptomatic ones. These samples (including cvs. ‘Pinot gris’, ‘Pinot noir’ and ‘Muscat blanc’) were tested for the presence of GPGV (RT-PCR, sequencing), and the virus was detected in 40 samples. It is stated that this new disease seems to be spreading in the Primorska region where it is causing considerable economic losses, and that it was also found in other regions of Slovenia in 2013. As in the other studies carried out in Europe, it is stressed that because GPGV could be found in symptomless plants, its role in the development of the currently observed grapevine disease should be further investigated.
Sources
Glasa M, Predajňa L, Komínek P, Nagyová A, Candresse T, Olmos A (2014) Molecular characterization of divergent grapevine Pinot gris virus isolates and their detection in Slovak and Czech grapevines. Archives of Virology 159, 2103-2107.
Mavrič Pleško I, Viršček Marn M, Seljak G, Žežlina I (2014) First report of Grapevine Pinot gris virus infecting grapevine in Slovenia. Plant Disease 98(7), p 1014.