ISHS Acta Horticulturae 217: IV International Workshop on Fire Blight
ATTEMPTS TO FIND THE MECHANISM BY WHICH ERWINIA HERBICOLA INHIBITS ERWINIA AMYLOVORA |
| Authors: | R.S. Wodzinski, T.E. Umholtz, K. Garrett, S.V. Beer |
| DOI: | 10.17660/ActaHortic.1987.217.38 |
| Abstract:
Erwinia herbicola strains Eh252, Eh246, and Eh159 are highly effective, moderately effective, and weakly effective antagonists of Erwinia amylovora strain Ea273, respectively, in field tests. When Eh252 was grown together with Eh246 or Eh159 in the same pear fruit, all strains grew at the same rate. These data do not support the previously proposed hypothesis that E. herbicola inhibits E. amylovora by depleting the nitrogen sources required for the growth of E. amylovora. Different strains of E. herbicola were grown to stationary phase in a glucose-asparagine medium, and then removed from the medium. When the medium was supplemented with asparagine, which had been depleted in the medium by the growth of E. herbicola, the growth of Ea273 was inhibited. However, Ea273 grew in the medium that had not previously supported the growth of E. herbicola. The degree of inhibition of the growth of Ea273 in medium that previously supported the growth of different strains of E. herbicola correlated well (in four of five cases) with the effectiveness of the E. herbicola strain in preventing infections of apple blossoms by Ea273 in field tests. Thus, toxin production may be important in the mechanism by which E. herbicola inhibits E. amylovora. | |
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