title: Antifungal activities of selected essential oils against Fusarium oxysporum f. sp. lycopersici 1322, with emphasis on Syzygium aromaticum essential oil.
abstract: The antifungal effects of four essential oils viz., clove (Syzygium aromaticum), lemongrass (Cymbopogon citratus), mint (Mentha × piperita) and eucalyptus (Eucalyptus globulus) were evaluated against wilt causing fungus, Fusarium oxysporum f. sp. lycopersici 1322. The inhibitory effect of oils showed dose-dependent activity on the tested fungus. Most active being the clove oil, exhibiting complete inhibition of mycelial growth and spore germination at 125 ppm with IC50value of 18.2 and 0.3 ppm, respectively. Essential oils of lemongrass, mint and eucalyptus were inhibitory at relatively higher concentrations. The Minimum inhibitory concentration (MIC) of clove oil was 31.25 ppm by broth microdilution method. Thirty one different compounds of clove oil, constituting approximately ≥99% of the oil, were identified by gas chromatography-mass spectroscopy analysis. The major components were eugenol (75.41%), E-caryophyllene (15.11%), α-humulene (3.78%) and caryophyllene oxide (1.13%). Effect of clove oil on surface morphology of F. oxysporum f. sp. lycopersici 1322 was studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). SEM observation revealed shrivelled hyphae while AFM observation showed shrunken and disrupted spores in clove oil treated samples. In pots, 5% aqueous emulsion of clove oil controlled F. oxysporum f. sp. lycopersici 1322 infection on tomato plants. This study demonstrated clove oil as potent antifungal agent that could be used as biofungicide for the control of F. oxysporum f. sp. lycopersici in both preventive and therapeutic manner.
authors.affiliation: Centre for Rural Development and Technology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Kamaraj College of Engineering and Technology, S.P.G.C. Nagar, Madurai Road, Virudhunagar, Tamil Nadu 626001, India.
authors.forename: Sasireka
authors.initials: S
authors.lastname: Rajendran
authors.affiliation: Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: Ankit
authors.initials: A
authors.lastname: Srivastava
authors.affiliation: Centre for Rural Development and Technology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. Electronic address: satyawatis@hotmail.com.
authors.forename: Satyawati
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: Bishwajit
authors.initials: B
authors.lastname: Kundu
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D031743:Cymbopogon / Q000737:chemistry; D005052:Eucalyptus / Q000737:chemistry; D005054:Eugenol / Q000032:analysis; D005670:Fusarium / Q000187:drug effects*; D020128:Inhibitory Concentration 50; D018551:Solanum lycopersicum / Q000382:microbiology; D027541:Mentha / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D000081222:Monocyclic Sesquiterpenes; D009822:Oils, Volatile / Q000737:chemistry / Q000494:pharmacology*; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes / Q000032:analysis; D027842:Syzygium / Q000737:chemistry*
chemical_list: D000935:Antifungal Agents; D000081222:Monocyclic Sesquiterpenes; D009822:Oils, Volatile; D000081223:Polycyclic Sesquiterpenes; D012717:Sesquiterpenes; D005054:Eugenol; C042686:humulene; C024714:caryophyllene; C515179:caryophyllene oxide
keywords: Essential oils; Fusarium oxysporum f. sp. lycopersici; Microscopy; Minimum inhibitory concentration; Syzygium aromaticum