Chemical Composition and Combinatory Antifungal Activities of Ammoides verticillata, Allium sativum and Curcuma longa Essential Oils Against Four Fungi Responsible for Tomato Diseases.

Abstract

Tomato is considered a model plant in genetics and is one of the most economically important crops of all those that exist in the world. Several species of fungi are reported on tomato fruit, causing damage both during cultivation and after harvest. Some of the appropriate actions that could be initiated to resolve the problem are to develop and search for new antimicrobial substances isolated from the bioactive natural products, such as essential oils. The aim of this work was to determine the chemical composition of essential oils of Ammoides verticillata, Allium sativum and Curcuma longa, to evaluate their in-vitro antifungal activities and in-vivo antifungal effect of essential oils to prevent the diseases caused by tomato. The essential oils obtained from aerial parts of plants were analyzed by GC/MS and tested for their antifungal activities against Penicillium expansum, Fusarium solani, Rhizopus stolonifer and Alternaria alternata using the radial growth technique method. The effectiveness in-vivo of the association between Allium sativum and Curcuma longa essential oils was also investigated on tomatoes inoculated by fungi. The essential oil from A. verticilata was mainly composed of phenolic compounds (54.4%), the A. sativum oil was mainly composed of sulfur compounds (91.5%) and C. longa oil was dominated by oxygenated monoterpenes (82.0%). The obtained results in-vitro antifungal revealed that individual essential oils of A. verticillata and A. sativum were more active than the essential oil of C. longa against all screened microorganisms. An important antifungal effect of A. sativum and C. longa essential oils blend was obtained against P. expansum (100%), F. solani (95.2%), R. stolonifer (95.1%) and A. alternata (48.5%). Furthermore, A. sativum and C. longa essential oils blends have demonstrated promising in-vivo antifungal activity to control infection of tomato against P. expansum and R. stolonifer. A. sativum and C. longa essential oil blends can be used as a natural food preservative and alternative to chemical fungicides to protect stored tomato against many phytopathogens.