In Hungary, detection of virus and virus-like diseases of grapevine began in 1960's at the Research Institute for Viticulture and Enology by János Lehoczky and his colleagues. At present, sixteen virus and virus-like diseases of Vitis vinifera are known to occur in Hungary.
Regular virological screening of grapevine varieties...started in 1972. The present system of screening (visual selection, indexing, ELISA) has been established using methods with continuous improvement according to recommendations of international organizations.
In the first year symptomless grapevine plants are selected and marked during surveys carried out twice in the vegetation period: at about flowering and in the second half of September. At the first selection time plants are sampled for ELISA.
In the spring of the second year, overwintered canes are checked by woody indexing on 8 indicator species in the field.
In the third and fourth years the nursery is evaluated twice again. At the end, the marked grapevine plants, giving negative results on all indicators in every case, are considered virus-free.
In autumn of the fourth year, the virus-free material is planted out under screenhouse and also in a special mother block (nuclear stock) for maintenance and propagation.
Mother blocks of virus-free scion varieties have been established on 2 ha and those of rootstock varieties on 0.5 ha planted with the following number of varieties included in the national list: 71 European scion — and 12 rootstock varieties or variety candidates/clones. It is necessary to increase the area of Pre-base, Base and Certified stocks exclusively with tested virus-free (clean) material.
Viruses and viroids are submicroscopic infectious particles which can cause disease symptoms on grapevine. These parasites are depending completely on the energy metabolism of the plant cell. To enter the host cell plant viruses depend on injuries or on transmission via invertebrates (insects, nematodes, etc.). Viruses are classified by many ch...aracters including particle morphology, host range and information content of the genome. At present about 70 viruses including 7 viroids infecting grapevine are known. In single or mixed infections they are potentially detrimental to the quality and quantity of grape production in any growing area of the world. Some viruses can cause severe economic damage in vineyards. In Hungary many important viruses and viroids have been detected in grape. This review summarises characteristics of viruses and the results of detection and characterization of virus and virus like diseases of grapevine in Hungary. The identification of the causal agent, its transmission, geographical distribution and the development of the diagnostic methods are also discussed.