The effects of the EtOAc extracts on the morphology of the pathogens were observed by FE-SEM. The same culture method used in the disk diffusion was employed to obtain specimens for FE-SEM. A small piece of membrane filter (Sigma) was then placed between the pathogen inoculum and Whatman filter paper containing the EtOAc extract, after which the plate was incubated for 2–3 days at 25 C. Mycelia on the membrane filter were subsequently fixed with 1% osmium tetroxide for 24 h at 4 C. After fixation, the samples were dehydrated in serially diluted ethanol (50%, 70%, 80%, 90%, 95% and twice at 100%) for 20 min at each concentration. The samples were then placed in isoamylacetate for 30 min twice, after which they were dried in a critical point dryer with CO2. Next, the fixed samples were mounted on stubs and coated with gold/palladium using an ion-sputterer in a high-vacuum chamber. Finally, the samples were examined by
FE-SEM/energy-dispersive spectroscopy (EDS) (S-4100, Hitachi Ltd., Kabushiki, Kaisha, Japan).