The Influence of Collembola on the Dissemination and Antagonistic Effect of Pseudomonas Fluorescens Against Pythium Ultimum in Soil

ABSTRACT

In this work, investigations were carried out to study the influence of the Collembola species Onychiurus fimatus or Folsomia candida and the B5 isolate of Pseudomonas fluorescens on the infection of sugar beet with Pythium ultimum. In laboratory experiments, the role of the collembolans for the transport and spread was examined of Ps. fluorescens in the soil.

Both Collembola species transferred Ps. fluorescens B5 to sugar beet seedlings not treated with bacteria and so a strong colonization of the rhizoplane is induced.

In container experiments it could be shown that the spread of the bacteria in soil from Ps fluorescens B5-treated to untreated sugar beet seeds by Collembola is possible. At the same time, this resulted in an inhibition of P. ultimum infection in the primordial untreated sugar beet seedlings. These plants survived in the containers with F. candida to 92% and in the containesr with O. fimatus to 78%. In the experiments without collembolans none of the untreated plants survived.

Keywords:

• antagonistic effect
• Collembola
• Pythium ultimum
• Pseudomonas fluorescens