The effect of Denai thyme essential oil, fustil aluminum and mancozeb-metalaxyl on the induction of cucumber plant defense system in interaction with cucumber ring rot disease caused by Phytophthora sp.

Growing of cucumbers in the form of a greenhouse in Iran has expanded a lot in recent years. In this study, the effect of Denai thyme essential oil and two fungicides, fustil aluminum and metalaxyl-mancozeb, were studied for greenhouse cucumber plant dieback disease caused by Phytophthora pseudofungus. In the greenhouse test, the effects of the mentioned treatments on the activity of peroxidase, catalase and phenylalanine ammonia-lyase enzymes in cucumber plants infected by Phytophthora sp. was contaminated, it was measured. The results of the effect of different treatments on the defense mechanisms of the cucumber plant showed that the highest activity of the three enzymes peroxidase, catalase and also the enzyme phenylalanine ammonialyase was related to the treatment of the infected cucumber plant treated with a concentration of 150 ppm fustil aluminum fungicide, which was on the sixth day after Contamination with the pathogen, the activity of the peroxidase enzyme reached ΔOD/Min/mg protein of 1.95. The trend of the activity of all three enzymes was increasing until the sixth day and then decreasing, so that on the tenth day after infecting cucumbers with the pathogen, the activity of this enzyme decreased in fustil aluminum treatment and reached 29/ΔOD/Min/mg protein. 1 receipt. The treatment using Fustil aluminum fungicide on all the days of sampling compared to all other treatments had a significant difference in terms of enzyme activity level. On all sampling days, enzyme activity in metalaxyl-mancozeb treatment was significantly higher than control. On the 10th day after sampling, the activity level of all three enzymes decreases in all treatments compared to the 8th day, but the process of enzyme activity in different treatments is the same as the rest of the days. In other words, all the treatments are able to increase the activity of this enzyme compared to the control, but more importantly, this enzyme is also affected by the days of sampling. The results showed that Danai thyme was able to induce defense enzymes against the pathogen on all sampling days. In other words, the essential oil of this plant can affect the defense mechanisms of the plant along with the chemical inducers, and in this way, reduce the damage caused by pathogens to the plant.