In Vitro Antibacterial Activity of Medicinal Plant Essential Oils Against Burkholderia gladioli pv. gladioli

Background: Saffron (Zaeferan in Persian), known as Red Gold, is obtained from the dried stigma of the Crocus sativus L. (Iridacea) plant. It plays a critical role in non-oil exporting in the economy of Iran, and the livelihoods of many farmers and workers depend on its yields. Burkholderia (Pseudomonas) gladioli pv. gladioli causes severe reductions the saffron yield in Iran. According to responsible authorities of Iran, no pesticides are registered or recommended for saffron cultivations (except for two herbicides). Most essential oils are listed as generally recognized as safe substances and can exhibit a crucial role in exporting pesticides free saffron.  Objectives: The study aimed to identify the most effective antibacterial essential oils against B. gladioli pv. gladioli. Methods: Essential oils were extracted using a clevenger apparatus from ۲۵ medicinal plants belonging to the Lamiaceae, Compositae, and Apiaceae families, followed by an initial evaluation through disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Dimethyl sulfoxide (DMSO) and amikacin served as a negative and positive control, respectively. Results: Out of ۲۵ essential oils, only ۴ of them exhibited antibacterial effects on this pathogen including Satureja hortensis (۲۲.۶۶ mm inhibition), Thymus vulgaris (۲۰.۳۳ mm), Trachyspermum ammi (۱۷.۶۶ mm), and Sclerorhachis leptoclada (۱۰.۶۶ mm). Their MICs were ۱, ۲, ۴, and ۳۲ µL/mL, respectively.  Conclusion: These findings highlight promising essential oils for controlling B. gladioli, supporting pesticide-free saffron production and safeguarding Iran’s valuable crop yields.

کلیدواژه ها:

Antibacterial activity ، essential oils ، Burkholderia gladioli ، Crocus sativus L. ، Pesticide-free crop protection ، Saffron