Articles
VARIABILITY OF SYMPTOMS INDUCED BY VIRUS INFECTIONS IN PRUNUS DOMESTICA SPP.
Many biotic and abiotic factors are responsible for variability among the symptoms induced by virus diseases.
A variety may be susceptible to a virus disease and tolerant to an other one but a virus disease may induce severe symptoms on one variety and remain latent with another.
The largest part of our knowledge concerning host-virus relations within fruit trees are still at a descriptive stage and even we must be very cautious when analysing the data obtained.
The make conspicuous the complexities inherent in the relations between host and virus, two examples will set an idea of the extreme variability of the symptoms observed with the Prunus domestica’s cultivars (chlorotic leaf spot and Sharka virus).
These two viruses having a filamentary form can contaminate the Prunus species but as the kind of reactions produced by the Sharka virus are rather well known, the syndroms induced by the chlorotic leaf spot (Pseudo pox) are for the while unknown.
The fact is unquestionable that a better understanding of the resistance goes through a deep knowledge of the physiological and biochemical processus involving the host-virus relations.
But it is urgent gathering the utmost information concerning the phenomenons of susceptibility and resistance of fruittrees against the virus diseases, having an economical importance.
Through that wide international cooperation new sources for resistance to the viruses will arise.