Influência de diferentes metodologias de esterilização sobre a atividade antifúngica de extratos aquosos de plantas medicinais

Three experiments were conducted in the Laboratory of Phytopathology of Federal University of Grande Dourados, Mato Grosso do Sul State, Brazil, to evaluate in vitro the antifungal activity of aqueous extracts of garlic, cinnamon and clove subjected to different processes of disinfection and/or sterilization against the development of Fusarium solani. The experimental design for each trial was completely randomized, with 5 treatments and 8 replicates. Aqueous extracts at a concentration of 20% were subjected to the methods of filtering (FI), water bath at 65oC (WB), autoclaving at 100oC (AT1), autoclaving at 120oC (AT2) and control treatment (PDA alone). Subsequently, the extracts were incorporated into PDA medium, added to Petri dishes, to where F. solani mycelium discs of 0.3cm diameter were transferred. Then, the plates were incubated at 25oC with 12-h photoperiod. The treatments were analyzed as to mycelial growth of the colony, percentage of inhibition and growth rate of F. solani. Increased fungal growth was observed for the control treatment, demonstrating the antifungal potential of the extracts. The sterilization method influenced the efficiency of garlic and cinnamon extracts. For garlic, FI led to the best results, whereas for cinnamon extract there were no differences among the methodologies FI, WB and AT1. The different methods used did not interfere with the efficiency of the aqueous extract of clove.