2.6. Assay of identified volatile compounds on mycelia growth in vitro
Different amounts of individual volatile compounds (technical
grade) were used to study the effect on radial growth of hyphae.
An agar plug (U 5 mm) was placed on the PDA and a Standard
amount of individual volatile compounds were added to another
plate. Then the two lidless plates were sealed with parafilm. Equivalent
amounts of sterile distilled water were used as the control.
After 7 days incubation at 28 C, the colony diameter was assessed.
For treatments in which the C. gloeosporioides agar plug was completely
inhibited, the original plug was transferred to the fresh PDA
in the absence of volatiles to assess whether the inhibition was
fungistatic or fungicidal. Following an additional five days on fresh
media the diameter of outgrowth was measured. Each experiment
was performed in three replications and the experiment was repeated
three times.