CYTOPATHOLOGY OF RESIN GLANDS FROM HOP PLANTS INFECTED WITH HOP STUNTVIROID

The glandular cells of resin glands from hop cones systemically infect ed with hop stunt viroid (HSVd) were examined for cytopathological cha nges. The ultrastructure of the cells of infected cones showed two imp ortant variations from cells of uninfected cones: distorted cell walls and a decrease in extracellular migration of electron dense substance . Electron probe X-ray microanalysis revealed that the electron dense substance was detected as insoluble lead salts which are equivalent to the alpha-acid fraction among the resinous substances. Based on these results, the decrease of alpha-acid in HSVd-infected hop cones is dis cussed.