Chemical composition, antifungal and phytotoxic activities of Cistus ladanifer L. essential oil and hydrolate

The use of synthetic chemical fungicides commonly applied in crop protection has been associ-ated with environmental and human health risks. However, essential oils (EOs) and other bio-products, such as hydrolates, are gaining more attention as eco-friendly alternative biofungicides. We analysed the chemical composition of essential oil (EO) and hydrolate obtained from hy-drodistillation of air-dried plants of Cistus ladanifer L. by GC-MS. To assess their potential applica-tion as biofungicides, we evaluated the antifungal activity and phytotoxicity of EO and hydrolate. The oxygenated sesquiterpenes was the dominant group in the EO (28.36%), and the oxygenated monoterpenes in the hydrolate (43.62%). We tested the effect of EO and hydrolate on the mycelial growth of three phytopathogenic fungi (Fusarium oxysporum f.sp. radicis-lycopersici, Rhi-zoctonia solani and Cryphonectria parasitica) and one oomycete species (Phytophthora cinnamomi). The EO and hydrolate inhibited the mycelial growth of all four fungal species. The potential anti -fungal effect of the hydrolate was subsequently evaluated in situ with the experimental pathosys-tem P. cinnamomi -Lupinus luteus. The results showed that the hydrolate application significantly reduced seedling mortality in all three strains of P. cinnamomi tested (MYC-18, CA-9 and CA-4) (ED50 = 165.5 mu l/ml, ED50 = 238.1 mu l/ml and ED50 = 234.1 mu l/ml, respectively). In phyto-toxicity tests with Raphanus sativus and L. luteus seeds, the EO and hydrolate showed dose -dependent and species-dependent phytotoxic effects. These results show the high potential the C. ladanifer hydrolate to be used in the production of biofungicides to control phytopathogenic fungi.