Studies on the effects of some alkaloids and alkaloidal salts on potato virus Y infectivity: I Effect of alkaloids

ABSTRACT

The inhibitory properties of two alkaloids, ephedrine and caffeine, which belong respectively to the phenylalkylamine group and to the purine group, were evaluated against the mosaic symptoms produced by PVY on Datura metel plants. Each alkaloid was either mixed with the virus inoculum or rubbed to the leaves before and after inoculation. When ephedrine - at various concentrations- was mixed with virus inoculum, the infectivity decreased gradually with increasing concentration and with lengthened time of contact, between ephedrine and virus form 60 to 180 min. With caffeine, the infectivity increased by increasing its concentration and decreased by lengthening the time of contact between caffeine and virus. When applied by rubbing, immediately [zero time] and 24 hours before and after virus inoculation ephedrine was superior to caffeine in inhibiting the virus infectivity