Articles
VIRUSES RECORDED IN PORTUGAL IN TOMATO PROTECTED CROPS
Tomato bushy stunt virus was detected only once in a greenhouse in the Algarve region.
A geminivirus, named tomato leafroll virus, recently detected in tomato field crops in a Southern area of the Country, is considered potentially important for protected crops as it may be transmitted by fresh seed and the symptoms in plants in the glasshouse are different from the symptoms shown by field plants.
This virus is thought to be transmitted by leafhoppers.
Tobacco mosaic virus has been identified on the basis of its virion morphology and by the symptoms caused in test plants like Nicotiana glutinosa L. and N. tabacum L.
Tomato bushy stunt virus was identified by the symptoms caused in several test plants, virion morphology, host ultrastructure and serological tests.
Tomato leafroll virus was purified from infected plants in the field and anti-serum was obtained by rabbit injection.
Gel-diffusion tests proved that the virus is closely related to beet curly top virus and enzyme-linked immunosorbent assay enabled the virus antigen to be detected in tomato and pepper and at lower concentration in potato, in some weeds and in leafhopper (Empoasca sp.) extracts.
Plants grown from fresh seed collected in infected fields showed symptoms of the disease.
The identification of the virus was further confirmed by abnormalities in the nuclei of infected cells and the results obtained, mainly in serological tests, led to the conclusion that the virus is probably a strain of beet curly top virus.
Some protection measures are mentioned in order to avoid the diseases caused by the viruses described.