Virus, COMOVIRIDAE, NEPOVIRUS .
Identification, Description, Biology, Epidemiology, Treatement, Possible misleading, Images
Causes wide range of symptoms on grapevine : shortening of internodes, zigzag growth and fasciation on the shoots; asymetry of the blade, resembling a fan, acute indentation on the leaves.
Chromogenic strains of the virus induce various patterns of yellow discoloration (yellow mosaic form).
Fruit set is poor, fewer and smaller bunches with aborted berries. Yield is reduced in more than 50% and longevity of the plant is low.
The causal agent is a nepovirus (virus transmitted by nematodes, with polyedral particles).
Several serotypes are recognized, some inducing distortion (grapevine fan leaf virus) others chromogenic symptoms (grapevine yellow mosaic and grapevine vein banding).
Particles with a bipartite genome.
It has a wide host range among perennial plants and trees and is transmitted easily by mechanical inoculation.
All the serotypes are transmitted efficiently by the nematode vector Xiphinema index in natural conditions.
Infected nematodes are present in deep parts of the soil, contaminating it and making the recovery of the soil difficult.
Infected propagating material is responsible for long distance spread of the virus and of the vector.
Through selection and production of virus free stocks by heat therapy and or meristem culture in order to use healthy scion and rootstock plant material.
Avoid using contaminated soils to eliminate virus reservoirs and to diminish nematode population.
Production of rootstocks and/or cultivars resistant to the virus are under way, including production of transgenic plants.
Similar symptoms on grapevine can be caused by other nepovirus occurring in other European and Mediterranean countries, like arabis mosaic (distantly related to GFLV and transmitted by Xiphinema diversicaudatum mainly), raspberry ringspot (RRS), in Western Germany and transmitted probably by Longidorus macrosoma , strawberry latent ringspot (SLR), in Germany and Portugal, and tomato black ring (TBR) transmitted by Longidorus attenuatus (in Western Germany and Greece).
HYP3 on line : Species (scientific name), Diseases (common names), Glossary, Crops.