Crown gall of plants.

  • Smith, Erwin F. (Erwin Frink), 1854-1927.
Date:
[1911]
Catalogue details

Licence: In copyright

Credit: Crown gall of plants. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Erwin F. Smith (With Pdates II and III) This disease is characterized by marked overgrowth of the affected tissues. It occurs on plants of many families and in various regions of the world. In the United States it has been designated “crown gall” because it occurs very frequently on the crown of the plant, but it is found also on roots and on stems above the earth surface. In Eu- rope where it occurs on grape, rose, raspberry, beet, etc., it is known by a variety of names : canker, krebs, wurzelkropf, broussins, rogna. For the past six years team work has been done on crown gall in the Bureau of Plant Industry by the writer and three colleagues, Dr. C. O. Townsend (first five years), Miss Alice C. Haskins (first two years), and Miss Nellie A Brown (last four years). Other co-workers have also contributed a little here and there,—cultures set, sections cut, flagella stained, chemical analyses made. A bulletin on this subject is in preparation and to this publication those readers are referred who desire further proofs in confirmation of the statements here affirmed. CAUSE OF THE DISEASE This disease is due to bacteria : not to fungi, not to myxomycetes, not to mites, not to frosts, not to disturbances innutrition. All these alleged causes have had their champions but they are not the true cause. They are all post hoc inferences based for the most part only on microscopic examinations made, in so far as organisms have been incriminated, in the later stages of the disease, when various sapro- phytes are certain to be present. Of clear cut and convincing experi- mental evidence in their favor there is not a scrap. Bacteria were seen by the writer in fresh unstained sections of im- mature and non-necrosed crown galls in February, 1904, and two years later we obtained convincing proof of the gall-producing power of a particular schizomycete, obtained from galls by means of agar poured- plates, sub-cultured on agar from the colonies, and inoculated into sound plants. This organism was then named Bacterium tumefaciens S. & T. Since that date our experiments have been continuous, and we have obtained successful inoculations from pure cultures and sub- cultures on more than a thousand plants. Sometimes we have failed but gradually we have come to know many of the sources of our fail- ures, and nothing in our experiments has led us to wish to modify in any material way our first published statement (Science, April 26, 1907, and Centralbl. f. Bakt., Abt. 2, Bd. XX, No. 1/3, 1907), or