Using ecological knowledge and molecular tools to develop effective and safe biocontrol strategies

Today’s farming systems undermine the well-being of communities in many ways: farming has destroyed huge regions of natural habitats, which also implies a loss of species and their ecosystem services (Sachs et al., 2010). Plant protection measures also causes problems for human health (Horrigan et al., 2002), and agriculture is responsible for about 30% of greenhouse-gas-emission (IPCC, 2007). Furthermore, emerging, re-emerging and endemic plant pathogens continue to challenge our ability to safeguard plant growth and health worldwide (Miller et al., 2009). Therefore, one of the major challenges for the 21st century will be an environmentally sound and sustainable crop production. Microbial inoculants containing microorganisms with beneficial plant-microbe interactions have a great potential to contribute to this objective (Berg, 2009; Bhattacharjee et al., 2008). Over the past 150 years, research has demonstrated repeatedly that bacteria and fungi have an intimate interaction with their host plants and are able to promote plant growth as well as to suppress plant pathogens (Compant et al., 2005; Lugtenberg & Kamilova, 2009; Weller et al., 2002; Weller, 2007; Whipps, 2001). All plant-associated microenvironments, especially the rhizosphere, are colonized in high abundances by antagonistic microbes (Berg et al., 2005a). Between 1 and 35% of the microbial inhabitants showed antagonistic capacity to inhibit the growth of pathogens in vitro (Berg et al., 2002, 2006). The proportion of isolates, which express plant growth promoting traits is much higher in general, and was found up to 2/3 of the cultivable population (Cattelan et al., 1999 …