In vitro and in vivo control of Alternaria alternata in cherry tomato by essential oil from Laurus nobilis of Chinese origin

BACKGROUND Many essential oils were reported to be used as natural, environmental friendly antimicrobial agents. The antifungal activity in vitro and in vivo of an essential oil extracted from Chinese local Laurus nobilis leaves against Alternaria alternata has been studied. RESULT The main components of the essential oil were investigated by means of gas chromatography-mass spectrometry and 14 components were identified. The main ones were eugenol, caryophyllene and cinnamaldehyde. The antifungal test showed that at 800 mu g mL(-1) of L. nobilis oil completely inhibited the growth of A. alternata. In addition, the conidial germination of the pathogen was significantly inhibited at 200 mu g mL(-1), and the weight of mycelia efficiently decreased at 500 mu g mL(-1). The invivo assay indicated that 500 mu g mL(-1) L. nobilis oil was effective in protecting cherry tomatoes (Lycopersicon esculentum) from infection of A. alternata, with an inhibition ratio of 33.9%. Scanning electron microscopy observations of the pathogen revealed significant morphological alterations in the hyphae. CONCLUSION This work suggested that L. nobilis oil could be used as a potential fungicide to control the post-harvest disease caused by A. alternata. (c) 2013 Society of Chemical Industry