Antifungal Effects of Foeniculum vulgare Mill. Herb Essential Oil on the Phenotypical Characterizations of Alternaria alternata Kessel.

The fungitoxicity of Foeniculum vulgare herb essential oil was evaluated by mycelial growth inhibition assessment in medium culture. The radial growth of the Alternaria alternata was completely inhibited at the oil levels of 500 and 300 ppm in poisoned food and volatile activity assessments, respectively. Microscopic observations using Light Microscope showed morphogenic changes in the test fungus with 300 ppm of the oil. These changes included a significant loss of conidiation, decrease hyphal diameter and induce cytoplasm condensation. The treatment with the oil also resulted in a highly lobate and bulbous anomalous structure on the hyphal tips. Essential oil of F. vulgare at 500 ppm effectively reduced the percentage of rotted tomatoes in in vivo. Gas chromatography-mass spectrometry analysis of the Fennel oil revealed that it was considered of 25 monoterpenoid compounds of which trans-anethole, estragole, and fenchone as the major components. Findings of the current study suggest that essential oils have natural phytochemical and could be used as a substitute bioactive compounds for chemicals in control of plant pathogenic fungi on fruits or vegetables.