Evaluation of Fungistatic Activity of Eight Selected Essential Oils on Four Heterogeneous Isolates Obtained from Cereal Grains in Southern Poland.

The aim of the study was to determine the relationship between the chemical composition of eight commercial essential oils (EsO) (garlic, grapefruit, lemon grass, tea tree, thyme, verbena, cajeput, and ) and their fungistatic activity in relation to four species of : , and . The species identification of isolates was confirmed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometer. The determination of qualitative and quantitative chemical composition of the EsO was carried out using the gas chromatography-mass spectrometry (GC-MS) method. The fungistatic activity of EsO was assessed by using the method of poisoned substrates. The data were compiled in the STATISTICA 13.0 program. The chemical composition of the tested oils varied; the dominant fraction, except for grapefruit and garlic oils, were monoterpenoids. The greatest similarity to the action of the synthetic pesticide Funaben T was found in four oils, i.e., thyme, lemongrass, verbena, and . The studies showed that and were characterized by a higher resistance to low oil concentrations, and and by sensitivity. The fungicidal activity of two EsO-dominant monoterpenoids-thymol and citral-has been confirmed.