Selection of antagonists for biocontrol of Xanthomonas euvesicatoria

Abstract

Xanthomonas euvesicatoria is a worldwide causer of pepper bacterial spot, a bacterial plant disease responsible for massive losses of fresh pepper fruits. Considering the current problems in management of bacterial plant diseases, biological control using antagonistic microbial strains with high potential for plant pathogens suppression emerges as a possible solution. The aim of this study was to select suitable antagonists for suppression of X. euvesicatoria among the bacteria, yeast and fungi from the genera Pseudomonas, Lactobacillus, Saccharomyces and Trichoderma, based on in vitro antimicrobial activity testing using the diffusion disc method. The results of this study have revealed that cultivation broth samples of the antagonists Lactobacillus MK3 and Trichoderma reseii QM 9414, as well as supernatant samples of the antagonist Pseudomonas aeruginosa I128, have showed significant potential to be applied in biological control of X. euvesicatoria. Further research would be required to formulate suitable cultivation medium and optimize bioprocess conditions for production of the proposed pepper bacterial spot biocontrol agents.