Chemical Composition and Antifungal Activity of Essential Oil of Thymus vulgaris Grown in Iran against Some Plant Pathogenic Fungi

This study was designed to examine the chemical composition and in vitro antifungal activity of hydrodistillation essential oil from the aerial parts of Thymus vulgaris. The chemical compounds were analyzed by GC and GC/MS. The oil analysis resulted in the identification of 45 compounds representing 96.75% of the oil. Thymol (36.81 %) and rho-cymene (30.90 %) were the main components of the oil. The oil was tested for in vitro antifungal activity against three phytopathogenic fungi included Drechslera spicifera, Fusarium oxysporum f.sp. ciceris and Macrophomina phaseolina by the agar dilution method. According to the results of the antifungal assay, the antifungal activity of the oil increased with rising in concentration. All of the tested concentrations of essential oil could completely inhibit fungal growth on 1600 mu LL-1. Although thyme oil on 800 mu LL-1 was not completely effective against the M. phaseolina, prevented from mycelia growth of other fungi, perfectly. In this study fungicidal activity only was observed on F. oxysporum and D. spicifera at higher concentrations than 800 mu LL-1. The antifungal activity of T. vulgaris essential oil probably due to the high concentration of oxygenated monoterpenes (thymol) and monoterpene hydrocarbons (rho-cymene).