Özet:

This study was carried out to determine antibacterial activity of Origanum onites L., essential oil and ethanol extract, against Pseudomonas syringae pv. tomato (Pst) and Clavibacter michiganensis subsp. michiganensis (Cmm). Plant material was collected from Tokat province in 2016. The study was carried under in vitro conditions and used King B medium. At concentrations, 10, 20, 30, 40 and 50% of the essential oil of O. onites was applied with method filter paper impregnation. The extract of O. onites was mixed with autoclaved King B medium to obtain final concentrations 1, 2, 3, 4 and 8%. And then 106 cell/ml of Pst and Cmm suspensions were placed on the medium containing the essential oil and extract. The media without essential oil and extract were used as the negative controls. Based on the results of the study, increase in the essential oil and extract concentration resulted in increase of the efficacy on pathogens. At concentration, of 50% essential oil of O. onites inhibited the growth of Pst and Cmm at a rate of 73% and 93%, respectively. At concentration of 8% extract of O. onites inhibited the growth of Pst and Cmm at a rate of 97% and 99%, respectively. In conclusion, it has been observed O. onites extract has higher antibacterial activity than essential oil.

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