Antifungal activities of ionic liquids against phytopathogenic Alternaria spp. strains

Abstract

A modern sustainable approach in agricultural practice would be a replacement of synthetic and toxic substances in the treatment of crop with benign and environmentally friendly compounds, by using principles of green chemistry. One of the possible directions could be using of ionic liquids (ILs), salts with melting points below 100 °C, which are well-known for manifesting antimicrobial activity. ILs can be used in the development of novel sources of antimicrobial agents such as antiseptics, biocides and antifungal agents. Furthermore, ILs have already been reported as alternative ‘green’ solvents for a wide range of reactions and technological processes. Considering the importance of research in the area of bioactivity of ILs for discovery of new green ILs for diff erent purposes, the aim of this study was to examine antifungal activity of nine newly synthesized ILs against phytopathogenic Alternaria strains isolated from from rice (A. padwickii), carrot (A. dauci) and linseed (A. linicola). Antifungal eff ect was estimated by micro-plate microdilution method for establishing minimum inhibitory (MIC) and minimum fungicidal concentration (MFC). All ionic liquids showed strain specifi c but good antifungal activity on Alternaria strains with MIC and MFC detected at the range from 9.23 mg/ml to 75.89 mg/ml. Only in case of the 1-(4-hydroxy-2-oxy)butyl -3-methylimidazolium chloride [OHC2OC2mIm][Cl], no antifungal eff ect on A. dauci were observed. Comparing to A. padwickii and A. dauci., A. linicola showed higher sensitivity to all tested ILs. Th e obtained results indicate the possibility of usage of ILs in biocontrol of plant diseases, representing their application in crop protection. However, further research is necessary in order to examine their toxicity and biodegradability in the environment.