3.5.1S
MOLECULAR APPROACH IN BIOLOGICAL CONTROL: POTENTIAL AND LIMITATIONS


GENEVIEVE DEFAGO

Department of Plant Sciences, ETHZ-Zurich, Switzerland

Over the past decade, novel applications of molecular techniques have broadened our insight into the basis of biological control of plant diseases. New tools are available for improving the efficacy of bacterial, fungal and viral biological control agents. Molecular probes are being developed to streamline the selection of better strains. Molecular phylogeny is increasingly important for assessing the impact of introduced agents on microbial communities, and for the identification of new strains. Molecular approaches have played a critical role in the assessment of potential risks associated with large-scale environmental releases of biological control agents (e.g., tracking both culturable and non-culturable cells, minimising microbe/gene escape). In turn, molecular-based studies in biological control have made major contributions to our understanding of microbial ecology, particularly in terms of how biological control agents interact with their abiotic environment and with other organisms in natural habitats. This overview of the potentials and limitations of molecular approaches in biological control will focus on (i) elucidating the mechanisms of disease suppression and understanding in situ gene expression, (ii) strain improvement and probes to select new strains, (iii) ecological studies including monitoring strain movement, detection of non-culturable organisms, and microbial interactions in natural habitats.