Determination of the antifungal effects of thymol, eugenol and 1,8-cineole essenti̇al oi̇l components against grey mold (botrytis cinerea) in vitis vinifera

ABSTRACT DETERMINATION OF THE ANTIFUNGAL EFFECTS OF THYMOL, EUGENOL AND 1,8-CINEOLE ESSENTİAL OİL COMPONENTS AGAINST GREY MOLD (Botrytis cinerea) in Vitis vinifera Benazir YELBOĞA Thesis of Master of Science, Department of Biology Thesis advisor: Asst. Prof. Dr.Sinem KARAKUŞ 2021, 96 In this study, the effects of Thymol, Eugenol and 1,8-Cineol UY (essential oils) in the prevention of losses caused by grey mold (Botrytis cinerea Pers.) in grapevine (Vitis vinifera L.) were investigated in vitro and in vivo. B. cinerea isolated from diseased vine vineyards was identified according to 18S rRNA gene sequence analysis. The effects of UY 25 µL, 50 µL and 100 µL doses on mycelial growth, spore germination and germ tube elongation were determined in vitro. In vivo study, the effect of 90% dilution solutions of the same UY on the formation of fungus lesions on grapevine leaves was evaluated. Thymol and Eugenol caused significant inhibition on fungal mycelial growth and the highest inhibition (100%) was determined in both UYs, especially at 100 µL doses. On the other hand, all doses of 1,8- Cineole could not have a significant effect on micellar development. Conidipor germination was inhibited by 25, 50 and 100 µL doses of Thymol compared to the control group by 22%, 45%, and 72% respectively, while the other two UYs did not have an inhibitory effect on conidyspore germination. On the other hand, while the length of the germ tube elongation of the fungus was 100% inhibition, especially at the doses of 50 µL and 100 µL of Thymol and Eugenol, an inhibition of 49% and 85% was determined in 1,8- Cineole, respectively. In vivo studies, all UY doses, especially 50 and 100 µL, suppressed the lesion formation of the fungus on live grape leaves by nearly 100%. The data obtained show that these two UYs, which are of biological origin and are non-toxic for environmental health, have the potential to be used in the control of B. cinerea. Keywords: Botrytis cinerea, Vitis vinifera, Thymol, Eugenol, 1,8- Cineole