Biological control of plant diseases by application of natural, epiphytic living non-pathogenic antagonists to the plant phyllosphere

摘要

Only few details are known about the influence of non-pathogenic microorganisms in the phyllosphere ofa host plant, in particular the action of non-pathogenic bacteria, which improve the growth or the defenseof plants against pathogenic bacteria and fungi. In general, the phyllosphere of plants is a biocoenosis ofdifferent non-pathogenic microorganisms, such as bacteria and fungi including yeasts that colonize thehost plant without causing significant morphological changes in the appearance of the plant (Beattie andLindow 1995; Burr et al. 1996). Some of these organisms have the potential to act as antagonists againstsome plant pathogens, such as fungi. Despite numerous investigations and practical approaches, thebiological control of plant diseases by antagonist treatment as natural replacement of fungicides in thephyllosphere is only marginally understood (Barbosa 1998; Elad et al. 2001; Boland and Kuykendall1997), and this limited knowledge explains failures of alternative methods using natural antagonistsinstead of excess fungicides (Myers 2000). Although the biological control of pathogenicmicroorganisms has a great potential to reduce or even to avoid the chemical treatment of crop plantswith pesticides, due to the performance, also the acceptance of this alternative approach is still low.