Determination of volatile and contact phase effects of essential oils
on hyphal morphology was described in our earlier study (Soylu et al.,
2006). For the determination of volatile phase effect of essential oils
on hyphal morphology, a mycelial agar disc from a 7-day old culture
was first placed in the centre of PDA plate and incubated at 20 °C for
2 days to allow mycelium to grow into the medium. After 2 days of
pre-incubation, different concentrations of essential oils used in vitro
studies were dropped (onto covers of Petri dishes), sealed by parafilm
and incubated at 20 °C for 3 days. Determination of contact phase
effect of essential oils on hyphal morphology was as described in an
earlier paper. Thin layers (1 mm) of agar blocks (3–4 cm2
) containing
mycelium were removed at one-day intervals for examination by light
microscopy. The blocks cut from growing edges were placed in a drop
of 50% glycerol on microscope glass slides, covered with glass cover
slip and examined using a phase contrast light microscope (Olympus
BX51, Tokyo, Japan)