ANTIFUNGAL EFFECT OF ESSENTIAL OIL AND DIFFERENT EXTRACTS OBTAINED FROM Nepeta meyeri ON Botrytis cinerea

The study concerns the antifungal effect of the aqueous and methanolic extracts, and the essential oil obtained from the aerial parts of Nepeta meyeri Benth. on Botrytis cinerea Pers. The fungus has been isolated from the infected plants of common grape Karaerik (Vitis vinifera L.) cultivating in vineyards in Uzumlu district, Erzincan (Turkey), and was cultured on potato dextrose agar medium in Petri dishes after the identification by 18S rRNA gene-based PCR assay. The concentrations of extracts from N. meyeri in Petri dishes were 2%, 5% and 10% (w/v) for aqueous extract (AE); 500, 1000 and 1500 ppm (v/v) for methanolic extract (ME), and 0.6, 0.8 and 1 mu L for essential oil (EO). After the treatments, mycelial growth, spore germination, and germ tube elongation were determined. Sterile distilled water at the same ratios was used for the control treatment. Thirty-six different compounds were identified in the EO of N. meyeri by GC/MS. The highest antifungal activity has been registered for EO of N. meyeri. The inhibition rates in 1 mu L/Petri of the EO were 80.72%, 18%, 38.15% on mycelial growth, spore germination and germ tube elongation, respectively. However, AE and ME of N. meyeri showed diverse effects on the studied parameters of B. cinerea. It is suggested that the favourable concentration of EO from N. meyeri can contribute to the prevention of B. cinerea infection (grey mould) which causes disease in vineyards.