Studies in the Cytology of Cancer: Continued from page 834

Abstract

Crown Gall Disease

Historical Development

The disease of plants characterized by irregularly shaped swellings or overgrowths at the region above the root or the crown is known as crown gall. This disease is an old one and has been known in Europe for the last seventy-five years or more. Its development has been attributed to mechanical injuries and frost effects. Sorauer (1922) points out that the swellings may occur in any part of the plant which has suffered mechanical injury. According to Hedgcock (1910a), crown gall was very destructive to the vine in parts of Germany, France, and Italy, but with the introduction of American stock later writers minimized its importance.

The bacterial origin of crown gall was first suggested in 1885, in connection with swellings or overgrowths on the crown of the grape vine. The methods of cultivating the organism believed to be responsible for the development of these overgrowths were crude. Cavara described a disease of the vine to which he refers as rogna or tuberculosis. He isolated an organism from infected vines and produced the disease by inoculating healthy plants. He measured the organism and found its dimensions to be 1.5–2 μ × 0.5 μ. Scalia observed galls on rose shoots, at the crown of the plant and also higher up on the shoots. He washed the organism from the tissue and added methyl violet stain to a drop of the washings for examination.