In vitro control of plant pathogenic Xanthomonas spp. using Poncirus trifoliata Rafin.

The secondary metabolites such as essential oil and pure compounds (limonin and imperatorin) from Poncirus trifoliata Rafin were tested for in vitro control of phytopathogenic bacteria of Xanthomonas spp. In vitro studies showed that the oil had inhibitory effect on Xanthomonas campestris pv. compestris KC94-17-XCC, Xanthomonas campestris pv. vesicatoria YK93-4-XCV, Xanthomonas oryzae pv. oryzae KX019-XCO and Xanthomonas sp. SK12 with their inhibition zones and minimum inhibitory concentration (MIC) values ranging from 13.1~22.1 mm and 62.5~125 μg/ml, respectively. Limonin and imperatorin also had in vitro antibacterial potential (MIC: 15.62~62.5 μg/ml) against all the tested Xanthomonas spp. Furthermore, the SEM studies demonstrated that limonin and imperatorin caused morphological changes of Xanthomonas sp. SK12 at the minimum inhibitory concentration (15.62 μg/ml). These results of this study support the possible use of essential oil and natural compounds from P. Trifoliata in agriculture and agro-industries to control plant pathogenic microorganisms.