بررسی اثر ضدقارچی اسانس آویشن‌شیرازی و نانوکپسول آن بر قارچ Fusarium graminearum در شرایط آزمایشگاهی

Fusarium head blight caused by Fusarium graminearum is one of the most important diseases of wheat all over the world. It causes the reduction of wheat yield quantity and quality. Due to the hazards of chemical fungicides for humans and the environment, it is essential to look for new and safe compounds. In this study, first,the antifungal activity of the essential oils (EO) of four plants; Rosemary (Rosmarinus officinalis), Wild marjoram (Zataria multiflora), clove (Syzygium aromaticum), and lavender (Lavandula angustifolia) against F. graminearum was investigated in vitro. To calculate the EC50 of EOs, a plague of fresh colonies was placed in the center of PDA plate containing different concentrations of each essential oil. The diameter of fungal growth was measured after one-week incubation at 26°C showing the highest growth inhibition (100%) by Z. multiflora essential oil at 450 ppm. In order to investigate the effect of nano capsulated form of Z. multiflora EO, the process of encapsulating Z. multiflora EO was done with the help of beta-cyclodextrin. DLS and FESEM test results confirmed the encapsulation of EO by beta-cyclodextrin; and then the EC50 of nano-capsule was first investigated at different concentrations. The results showed that the 450 ppm of EO nanocapsule inhibited mycelium growth as high as EO (100%), and individual application of Beta-cyclodextrin nanomaterial did not affect fungal mycelial growth. Furthermore, 450 and 600 ppm of both EO and its nano-capsule showed fungistatic effects. Concentrations of EO(260/1ppm) and its nano-capsule(367/2ppm) which were able to inhibit 95% of fungal growth were selected and studied their effect on fungal mycelium growth in the Broth medium. The results showed that the EO and nano-capsules inhibited 92 and 90 percent of mycelial growth in the broth medium, respectively. The effect of EO and nanocapsule on the germination of fungal spores at concentrations of 200, 300, 450, and 600 ppm was investigated. Results revealed that 24 and 48 hours after the treatment, EO and nano-capsule at 450 ppm prevented the fungal spore germination for 92% and 83% and at 600 ppm for 85%, and 93%, respectively. As a result, 450 ppm of EO and its nano-capsules which showed the highest fungal growth inhibitory effects, was chosen to apply in green greenhouse.