Antibacterial Activity Of Cinnamon Extract And Its Preventive Effect On Cucumber Powdery Mildew

Plant derived fungicides have attracted widespread attention of agricultural workers because of their rich plant resources,wide sterilization range and low toxicity.Cinnamomum cassia extract has strong bacteriostatic and disease prevention effects,and has certain utilization potential in plant disease control.In this paper,the antifungal activities of the extracts were studied;The antibacterial effect of cinnamon petroleum ether extract was determined by mycelial growth toxicity,microscopic observation of spore germination,determination of mycelial related physiological indexes and scanning electron microscope observation of mycelial morphology;Pot experiment was conducted to study the control effect of petroleum ether extract on cucumber powdery mildew,determine the relevant physiological and biochemical indexes of leaves,observe the morphological changes of powdery mildew spores and hyphae under scanning electron microscope,and explore the effect of cinnamon petroleum ether extract on cucumber powdery mildew resistance;The antibacterial active components of cinnamon petroleum ether extract were verified by TLC,and the following results were obtained:1.The inhibition rates of 10 mg/m L Cinnamomum cassia petroleum ether extract on the mycelial growth of Fusarium moniliforme was 51.84%;100mg/m L Cinnamomum cassia petroleum ether extract had strong control effect on the leaves infected with cucumber powdery mildew,and the control effect could reach 57.81%.2.The IC₅₀of Cinnamomum cassia petroleum ether extract on mycelial growth and spore germination of rice seedling blight were 7.92mg/m L and 6.99mg/m L,respectively;With the increase of the concentration of Cinnamomum cassia petroleum ether extract,the relative conductivity and malondialdehyde content of mycelium increased gradually;Under scanning electron microscope,the hyphae of Fusarium moniliforme treated with petroleum ether extract were observed to be deformed and shrunk.3.In the pot experiment,Cinnamomum cassia petroleum ether extract has a certain preventive effect,therapeutic effect and eradication effect on cucumber powdery mildew,and its preventive effect is as high as 73.68%,which is close to the control effect of pesticide Triadimefon on cucumber powdery mildew of 78.45%;The therapeutic effect was 53.40%;The eradication effect was 37.94%.Preventive treatment and treatment treatment treatment with cinnamon petroleum ether extract can reduce the content of malondialdehyde in cucumber leaves,increase the activity of defense enzymes(POD?CAT?PAL?SOD?PPO).A small amount of spores of powdery mildew were observed to germinate and shrink under scanning electron microscope;A few spores produce germ tubes;Hyphae were few,distributed disorderly,and the morphology of hyphae was shrunk and distorted.The process of spore germination of powdery mildew was delayed to the greatest extent and the formation of hyphae of powdery mildew was inhibited.4.The main components of Cinnamomum cassia petroleum ether extract were verified by TLC.To some extent,it was certificated that the main antifungal component of Cinnamomum cassia petroleum ether extract was cinnamaldehyde.