The Protective role of Pseudomonas sp PCI2 on post-harvest deterioration of tomato caused by Alternaria alternata

Abstract

The high moisture content and water-soluble nutrients in tomato fruits make them perishable and susceptible to a number of fungal pathogens that cause postharvest rots. The Alternaria genus, widely distributed in nature, includes pathogenic species that can infect field crops or cause significant post-harvest damage, behaving as a facultative pathogen that is favored by stress, maturity and senescence of the host. In the tomato fruit, the conidia of the fungus germinate and penetrate through wounds and the infection remains latent until maturity, when tissues weaken. A. alternata infection is visualized as dark brown to black, smooth, slightly sunken, firm-textured lesions that can reach several centimeters in diameter. The application of fungicides is a common strategy used in an attempt to minimize post-harvest losses; however, this practice has caused environmental problems due to its residual toxicity, stimulated the appearance of strains resistant to active principles and generated concern for human safety and animal. A sustainable alternative is the development of products based on biological control agents. Among them, bacteria of the Pseudomonas genus have been reported as efficient against various fungi.