Accumulated data and results from the recent study of dsRNA isolated from grapevines used in experiments of insect and graft transmission of 'Shiraz' disease

RT-PCR amplicons of dsRNA isolated from various grapevines, which were used in the experiments of transmission of 'Shiraz' disease (SD) from 'Cinsaut Blanc' clone P163/12 to SD-susceptible 'Merlot' and 'Shiraz' using mealybug Planococcus ficus and grafting were investigated. The amplicons were generated in RT-PCR based on virus-specific or random hexamers oligonucleotide primers. Standard molecular techniques and high-throughput sequencing (HTS), respectively, were applied. The results supported the hypothesis that GVA M5v variant present in 'Cinsaut Blanc' P163/12, which is a member of group II of GVA variants associated with SD, is crucial for developing this disease. HTS data did not reveal any other grapevine viruses besides GLRaV-3 and GVA in SD-affected grapevines, except for GVE which, however, was not present in all diseased plants.