Effects of Thymol on the Morphology of the Main Fungi Causing Pomegranate Fruit Rot ^†

Pomegranate fruit rot leads to the loss of a significant quantity of fruit worldwide. In the present study, the antifungal effects of thymol on the morphology of Aspergillus niger and Penicillium commune as the main fungi causing pomegranate fruit rot were investigated in in vitro conditions. Examination of cell morphology using scanning electron microscopy (SEM) in Aspergillus niger colony showed that cell deformation was observed due to the destruction of the cell membrane and loss of cell wall strength at a concentration of 250 µg mL⁻¹ (50% FC) after 168 h. Produced hyphae had irregular branching and no spore production was observed. Evaluation of Penicillium commune colony cell morphology using SEM showed that thymol at a concentration of 250 µg mL⁻¹ (50% FC) caused superficial wrinkles, bifurcation of the hyphal apex, and no spore production was observed.