Biological effects of essential oils and extracts
S. Malekpur; S. Nosrati; B. Behboodian; J. Gholamnezhad; M. Armin
Abstract
In the present study, first, an in vitro experiment was conducted to study the effects of Thymus vulgaris L., Foeniculum vulgare Mill., Rosmarinus officinalis L., and Mentha piperita L. water extracts on reducing the growth of Fusarium rot disease factor of cucumber (Fusarium oxysporum f. sp. radicis-cucumerinum ...
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In the present study, first, an in vitro experiment was conducted to study the effects of Thymus vulgaris L., Foeniculum vulgare Mill., Rosmarinus officinalis L., and Mentha piperita L. water extracts on reducing the growth of Fusarium rot disease factor of cucumber (Fusarium oxysporum f. sp. radicis-cucumerinum (forc)) by the saturated paper disk method. According to the results, the water extracts of Th. vulgaris, F. vulgare, R. officinalis, and M. piperita at a concentration of 250 ppm with the inhibitory zone diameter of 24.66, 17.33, 11.66, and 10.33 mm, respectively, showed the highest antifungal activity compared to the control (the inhibitory zone diameter of 3.66 mm). Then, it followed by a greenhouse experiment to investigate the effects of Th. vulgaris and F. vulgare water extracts on the cucumber cv. Nagene treated with F. oxysporum. The water extract of Th. vulgaris at a concentration of 200 ppm with the disease index of 31% showed the greatest reduction in the disease symptoms compared to the infected control and the F. vulgare treatment with the disease indices of 82.66 and 42%, respectively. Study on the activity of polyphenol oxidase, β-1, 3-glucanase, and peroxidase enzymes under the greenhouse conditions showed that the activity of all three enzymes had an increasing trend. So that the activity of enzymes in the combined treatment of Th. vulgaris water extract (200 ppm) and pathogen increased respectively from 1.12, 1.11, and 0.27 ΔOD/min/mg protein on the first day after the inoculation to 5.25, 4.81, and 2.88 ΔOD/min/mg protein on the 12th day, and it had a significant difference with the control. Considering the results of this research, it was found that the water extract of Th. vulgaris, in addition to the direct fungicidal effect, could increase the activity of defense enzymes in the cucumber plants resulted in the host plant resistance induction against the pathogen.
