Distribution and partial molecular characterization of Grapevine leafroll-associated virus 2 (GLRaV-2) found in Croatian autochthonous grapevine (Vitis vinifera L.) germplasm / Verbreitung und partielle molekulare Charakterisierung des Grapevine leafroll-associated virus 2 (GLRaV-2), das in kroatischem autochthonem Keimplasma von Weinreben (Vitis vinifera L.) gefunden wurde

Study of Grapevine leafroll-associated virus 2 (GLRaV-2) distribution was conducted on 13 Croatian autochthonous grapevine cultivars or cultivars which are supposed to be autochthonous included in clonal selection: Babica, Babić, Glavinuša, Grk, Ljutun, Maraština, Mladinka, Ninčuša, Plavina, Plavac mali, Posip, Vlaška and Vugava. All of them are grown in the southern part of Croatian coastal region (Dalmatia). Sampling was done during autumn 2007, and only a few samples of cultivar Babic were also collected during 2008. All samples were tested for the presence of GLRaV-2 using DAS-ELISA test. Out of 1100 tested grapevine accessions, the presence of GLRaV-2 was determined in 45 samples (4.1%). No virus was detected in seven grapevine varieties (Grk, Ljutun, Mladenka, Nincusa, Plavina, Posip, Vlaska). Minimal infection rate was determined in the cultivar Vugava (0.8%) while the most infected cultivar was Babić in which out of 98 analyzed grapevine accessions 33 (33.7%) were positive. All virus-positive tested vines contained mixed infections of several viruses and no vine was infected by GLRaV-2 only. In 14 different, randomly selected grapevine accessions the presence of GLRaV-2 was also confirmed by RT-PCR using the GLR2CP1/GLR2CP2 primer pair. RT-PCR products from four different grapevine accessions were sequenced. Sequences of gene segment coding for the viral coat protein revealed between 97.9% and 99.6% similarity on the nucleotide level, with absolute similarity on amino-acid level. Sixteen grapevine accessions were selected for transmission to herbaceous host Nicotiana benthamiana, but GLRaV-2 was not successfully transmitted to this host. To our knowledge this is the first report of GLRaV-2 in Croatia. Die Studie über die Verbreitung von Grapevine leafroll-associated virus 2 (GLRaV-2), wurde an den folgenden 13 kroatischen autochtonen oder als autochton geltenden Rebsorten durchgefühlt: Babica, Babić, Glavinusa, Grk, Ljutun, Maraština, Mladinka, Ninčuša, Plavina, Plavac mali, Pošip, Vlaška und Vugava. Alle diese Rebsorten werden im südlichen Teil der kroatischen Küstenregion (Dalmatien) angebaut und es werden derzeit Klone von ihnen entwickelt. Die Probennahme wurde im Herbst 2007 vorgenommen, nur einige Proben von der Rebsorte Babic wurden erst im Laufe des Jahres 2008 genommen. Alle Proben wurden mittels des DAS-ELISA-Tests auf Anwesenheit von GLRaV-2 geprüft. Von den 1100 geprüften Weinreben wurde GLRaV-2 bei 45 Proben (4,1%) festgestellt. Bei si