A study of the virus diseases "Big bud" of tomato and "Yellow Dwarf" of tobacco.

Abstract

The two virus diseases "big bud" of tomato and "yellow dwarf" of tobacco are transmitted by the same insect vector. Both were transmitted by grafting but not by sap inoculation. Big bud but not yellow dwarf was transmitted by dodder. Nicotiana glauca Graham was a symptomless carrier of both viruses. Potato was infected by big bud but not by yellow dwarf. Evidence from experiments and field observations indicates that big-bud transmission occurs during summer whereas yellow-dwarf infection can occur throughout the year. From this and other evidence (anatomical, lack of cross protective power, symptoms) it is concluded that the two diseases are caused by different viruses.