Effect of Pistacia atlantica Subsp. Kurdica essential oil and acetic acid on Botrytis cinerea growth in culture media, grape and cucumber fruits

The effect of Pistacia atlantica Subsp. Kurdica essential oil (EO) and acetic acid against Botrytis cinerea growth was investigated in synthetic media, cucumber and grape fruits. The antifungal assay was determined on PDA plates amended with thirty-three concentrations of this oil (250, 1000, 1500 to 26000 μι/ι). This study was conducted for acetic acid of 0.1% alone at concentrations of 5, 15 and 25% .Also 0.1% of each dilutions of acetic acid were added to a series of sterile molten PDA that contain different concentrations of essential oil ranging from 50 to 3000 μι/ι. EO inhibited radial growth on potato dextrose agar (PDA) in a dose-dependent manner. The growth was completely prevented by EO at 26000 ppm on PDA. In combination with 0.1% acetic acid 25% in fungal growth medium, minimum inhibitory concentration (MIC) of EO reduced to 3000 ppm. During 31 days of cold storage of cucumber and 60 days of grape at 4°C, the decay of these fruits caused by B. cinerea was reduced to 10% by using MIC of EO. Scanning electron microscopy (SEM) was done to study the mode of action of the oil in Botrytis cinerea and it was observed that treatment with the oil leads to distortion and thinning of the hyphal wall and the reduction in hyphal diameter. The results suggested the potential substitution of the antifungal chemicals by this EO and acetic acid as a natural inhibitor to control the growth of this mold in fruits such as cucumber and grape.

Pistacia atlantica essential oil, Botrytis cinerea; cucumber, grape, antifungal effect, acetic acid, SEM.