INVESTIGATIONS ON SYMPTOMATOLOGY, TRANSMISSION, ETIOLOGY, AND HOST SPECIFICITY OF BLACK CURRANT REVERSION VIRUS

Experiments in growth chambers with varying light conditions have shown that under continuous light with an increase of the red part of the spectrum spot, banding and ring chloroses, typical for the virus, developed on leaves of reversion diseased black currants.
This technique allows an early diagnosis and selection of young and mother plants.

Under the specific light conditions gallmite (Cecidophyopsis ribis Westw.) infected seedlings of the cultivar "Baldwin" develop these typical symptoms.
Under laboratory conditions the retention of the virus in the vector can last up to 25 days.
All mite stages were able to transmit the virus.

The etiology of reversion has been demonstrated and the virus nature of the causal agent is verified.
The virus causing reversion is identical with the Y-virus of potato.
Like in potato there are three strains of varying pathogenicity in Ribes.
The Virus is mechanically transmissible to Nicotiana glutinosa, N. rustica, Solanum demissum "A 6", and other herbaceous test plants for potato-Y-virus, and is identified serologically and in the electron microscope.
The reinfection from N. glutinosa to Ribes nigrum carried out by the "leaf-to-leaf inoculation technique" was successful.
Apart from the virus, gallmites transfer a spore producing bacterium, called "endophytic bacillus" by Silvere and Romeikis (1971). In extensive tests this bacterium showed no pathogenicity and was isolated from all galled but reversion free plants.

Red and white currants can also be infected by gallmites with reversion.

I International Symposium on Small Fruit Diseases

H. Jacob

https://doi.org/10.17660/ActaHortic.1976.66.13