Synergistic effect of oligochitosan and silicon on inhibition of Monilinia fructicola infections

BACKGROUND: Oligochitosan has broad-spectrum antimicrobial activity and shows an obvious inhibitory effect on phytopathogens. In addition, as an exogenous elicitor, it can induce various defence responses, including affecting the activities of several defence-related enzymes and substances in some plants. Owing to this dual function of oligochitosan, it can be used to control postharvest diseases of fruits. Silicon, like oligochitosan, also has a dual function. In this study the synergistic effect of oligochitosan and silicon on the decay control of apple fruit was investigated. RESULTS: In vitro, both oligochitosan and silicon significantly inhibited spore germination, germ tube elongation and mycelial growth of Monilinia fructicola, with higher concentrations having a greater effect. The synergistic effect of oligochitosan and silicon at half-maximal inhibitory concentration on disease control at 25 degrees C was much better than the effect of oligochitosan or silicon alone, not only in vitro but also in vivo. CONCLUSION: The results showed that a combination of oligochitosan and silicon had a synergistic effect on the control of disease caused by M. fructicola in apple fruit at 25 degrees C.