Occurrence of the important grapevine viruses in population of Croatian autochthonous grapevine varieties from Kastela region

Due to mild Mediterranean climate grapevine is main woody culture grown for centuries in Kastela region, which resulted in accumulation of great number of different foreign and autochthonous grapevine varieties. Sanitary status of autochthonous cultivars from that region is practically unknown. The investigation had been induced by possibility that deteriorated sanitary status can cause lack of interest or even abandoning of certain autochthonous varieties. Survey was made in 11 commercial vineyards on total of 323 plants included in mass positive clonal selection. Autochthonous cultivars included in investigation were: Babica, Glavinusa, Ljutun, Mladenka, Nincusa and Vlaska. The samples were collected during autumn 2006 from each individual plant investigated. Each sample was represented by at least three well wooded cuttings taken from different basal parts of plant. The collected samples were tested on presence of five viruses using enzymatic-serological method ELISA: Arabis mosaic virus (ArMV), Grapevine fanleaf virus (GFLV), Grapevine leafroll-associated virus 1 (GLRaV-1), Grapevine leafroll-associated virus 3 (GLRaV-3) and Grapevine virus A (GVA). From the same plants samples were taken during autumn 2007 and using ELISA-test the investigation was extended on two more viruses: Grapevine fleck virus (GFkV) and Grapevine leafroll-associated virus 7 (GLRaV-7). The results revealed that all tested plants were infected with at least one of viruses tested. The most widespread virus was GLRaV-3 found in all analyzed samples (323), followed by GVA found in 265 (82.04%), GLRaV-1 found in 244 samples (75, 54%). Occurrence of other viruses were much more scarcer: GFLV in 84 samples (26, 01%), GFkV in 59 (18, 27%), ArMV in 46 (14, 24%). The presence of GLRaV-7 was not confirmed in any of analyzed samples. Obtained results showed very important roll of determination of sanitary status as a complement to the clonal selection. The restoring of acceptable health status of germplasm is the main prerequisite for objective evaluation of its productive and oenological potential. Finally, virus tested propagation material will be essential for the establishment of new vineyards.