Using Varronia curassavica (Cordiaceae) essential oil for the biocontrol of Phytomonas serpens

Abstract The protozoa of the genus Phytomonas cause diseases in crops of agricultural and economic importance; however, there is no control registered for these phytopathogens. The objective of this research was to evaluate the antiprotozoal activity of essential oils (EOs) from seven Varronia curassavica genotypes and their effects on Phytomonas serpens promastigote forms. Chemical analysis of the essential oils with gas chromatography-mass spectrometry (GC–MS) for the genotypes VC-002, VC-104, VC-202, VC-302, VC-303, VC-601, and VC-701 demonstrated that α-pinene (56,69%), 7-cyclodecen-1-one,7-methyl-3-methylene-10-(1-propyl) (48,63%), germacrene D-4-ol (32,16%), ar-curcumene (20,37%), 7-cyclodecen-1-one,7-methyl-3-methylene-10-(1-propyl) (19,32%), E-caryophyllene (21,78%), and ar-turmerone (28,36%) were the major compounds for each genotype, respectively. All seven EOs demonstrated antiprotozoal activity, and the EO from genotype VC-202 had a lower IC 50 (13.94 μg/mL) and permanent effect against P. serpens . The images obtained by fluorescence microscopy and the data from fluorescence spectrophotometry using propidium iodide (PI) demonstrated alterations in the permeabilization of the cytoplasmic membrane of P. serpens cells treated with the EO from VC-202. The EOs of different V. curassavica genotypes presented wide chemical variability and demonstrated antiprotozoal activity against P. serpens . Currently, there are no reports about EO activity against Phytomonas ; therefore, the EO of genotype VC-202 is a potential raw material for formulations of bioproducts for Phytomonas control.