Antifungal activity of essential oil of aromatic and medicinal plants on Colletotrichum gloeosporioides

Abstract

Essential oils (EO) from aromatic and medicinal plants (MAP) are considered a feasible alternative for the control of phytopathogenic fungi of agronomic importance, due to the active principles they possess. The present study evaluated in vitro the antifungal activity of thyme (Thymus vulgaris L.) and rue (Ruta graveolens L.), on Colletotrichum gloeosporioides, using the disc inhibition method in agar, concentrations from 10 to 100 % of each EO were used. The phytochemical composition was analyzed by GC-MS. Morphological observations were made with a scanning electron microscope (SEM). A noticeable antifungal activity was observed from 50 to 100 % of the concentration of thyme EO. The rue EO showed a fungistatic effect for 6 days. The phytochemical analysis showed carvacrol (35.95 %) and p-cymene (41.18 %) as major components of thyme EO, and 2-nonanone (24.24 %) and 2-undecanone (68.69 %) for rue. The evaluated EO´s have a significant impact on morphological level at concentrations of 60 %. The strong antifungal activity of thyme on C. gloeosporioides could be used as a natural alternative for the control of the pathogen.