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Julius Kühn-Institut (JKI)
Federal Research Centre
for Cultivated Plants

Head
Prof. Dr. Johannes A. Jehle

Address
Heinrichstraße 243
64287 Darmstadt, Germany

Office
Ms Sylvia Adamek
Ms Susanne Ganzer
Tel: +49(0)6151 407-0
Fax: +49(0)6151 407-290
E-mail: bi@  julius-kuehn.  de

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Institute booklet

Interactions and modes of action in biological plant protection

Biological Control uses potential natural antagonists of plant diseases and plant pests. Interactions of pests and their antagonists as well as their efficacy are investigated.

Crop pests and pathogens and their natural antagonists can interact with each other in many ways and at different levels, e.g. on molecular, cellular, organismic, population dynamical or evolutionary level. Each level of this reciprocal relationship influences the effect of an antagonist. This may be instantly visible in laboratory, greenhouse and field experiments or in the long term, when a pest or pathogen adapts to the respective antagonists and develops resistance. Only a deeper understanding of these interactions allows utilizing the full potential of natural antagonistic organisms and natural products. Therefore, the elucidation of the mode of action of antagonists and natural products is the basis for any new development of biological control strategies.

Histopathology and diagnosis of insect pathogens

We conduct microscopic investigations on insects and isolate microorganisms and viruses from their tissues, with the aim to use these agents for insect pest control. The discovery and diagnosis of natural pathogens of insects are therefore the basis for the development, optimization and monitoring of bio-control methods.

Scientists involved:
Dr. Regina Kleespies
Sarah Biganski

Biological and molecular effects of insect viruses

Insect viruses are among the most specific and most environmentally friendly plant protection products at all. They are fully harmless to humans and the environment, but of resounding efficacy against certain caterpillars, such as the codling moth.

Scientists involved:
Prof. Dr. Johannes Jehle
Dr. Jörg Wennmann

Bacteria and fungi used as insect pathogens

Insect pests may also suffer from bacterial and fungal infections. For more than a century these agents have been explored for their service in plant protection. Several commercial insect pathogenic bacteria and fungi were discovered at our Institute. Their use in plant protection practice increases progressively.

Endophytes for biological plant protection

Insect pathogenic fungus B. bassiana on rape leaf

Various fungi can be used as so-called endophytes living in plants without causing pathogenic symptoms. We try to establish insect pathogenic fungi as endophytes in different crops and finally in their seeds. Thus, both insect pests and plant diseases could be controlled. To prove endophytic growth, both microscopic and molecular methods are developed.

 

Scientists involved:
Dr. Regina Kleespies
Dr. Eckhard Koch
Dr. Dietrich Stephan

Mechanisms of action of natural products

Plant extracts and other natural products are used against pest insects and fungal or bacterial plant diseases. These substances may have a direct effect on the pathogens, thus causing their death or inhibiting their reproduction. Another mechanism of action is based on the strengthening of plant immune response. As a consequence, they can defend themselves against pathogens. Our Institute performs research on the various mechanisms of action.

Scientists involved:
Dr. Annegret Schmitt

Do lunch or be lunch

Beneficial insects and mites prey or parasitize pests. A key point is that these beneficials utilize the target pests preferably as prey or host and overcome their defense reactions. These specific traits must be preserved, e.g. in commercially grown mass rearings for the use of beneficials at large scale. We develop methods to assess the quality of beneficial organisms and to optimize them. Also important are potential interactions of the selected beneficials among each other and also with other predators or parasites, as they are also part of food webs in the farming system.

Scientists involved:
Dr. Annette Herz
Silvia Mátray
Mokhtar Abonaem