Studies on Crown Gall Transplants.

Abstract

That great difficulty is experienced in transplanting spontaneous animal tumors to other animals of the same species is well known. Yet, transplanted animal tumors once established may be transferred from animal to animal of the same species for many years with considerable ease. The transplants take approximately in all cases.

Jensen claims 1 that successful transplantations of spontaneous and artificially produced crown galls of the sugar beet may be made on the sugar beet without stimulating the host tissue itself to crown gall formation.

The present report deals with the inoculation of young parts of tobacco, tomato, geranium, sugar beet, yellow and red mangels, rubber and castor bean plants with pieces of crown gall tissue arising on similar plants from inoculations, with virulent strains of Bacterium tumefaciens. Pieces of crown gall tissue of Ricinus communis, when transplanted into the same and other Ricinus plants, produce small crown galls in all cases. Transplants of the growths of the second generation to other plants were also found to be effective in producing crown gall tissue. These new growths, however, were generally much smaller than those produced by the primary inoculation with the bacterium or with the crown gall inoculum.

Kicinus crown gall tissues transplanted to growing portions of the tobacco plant were also found to produce galls. Similar results were obtained with crown galls of tomato, geranium and the beet. These neoplasms, however, are not conclusively of the inoculum type, but are generally of the host type, for, while it is impossible to distinguish Ricinus crown gall on tobacco from tobacco crown gall, it is clear that these crown galls are strictly of tobacco type and origin. The crown gall tissue on the tobacco became differentiated and formed leafy shoots with characteristic tobacco leaves.