Studies On Physiological Pathogenesis Mechanisms Of Soil-Borne Diease Of Cucumber Fusarium Wilt

Fusarium oxysporum f. sp. cucumerinum (FOC) is the causal agent of cucumber (Cucumis sativus L.) Fusarium wilt, a soil-borne disease that can cause severe losses in yield and quality of cucumber. Currently, the progress of the pathogenic mechanism research of Fusarium wilt is slow. There is an argumentation on plugging and systemic toxicity. In this study, we used soil and nutrient solution to culture.The effects of Foc on cucumber biomass, antioxidant activity, the content of soluble suger and protein, the production of FA were investigated to prove that FA may have important pathogenic role, so as to provide a theory for the cucumber Fusarium Wilt treatment, which is to achieve the sustainable development of cucumber industry.1. The root activity of cucumber decreased by63%after pathogen infection, which is due to the damage of the root membrane function result in intracellular metabolism disorder, and decrease the ability to restore the TTC in root. It will affect the shoot growth of cucumber. Because pathogen infection, some cellulose were degraded. Cellulose content decreased by30%. However, having stimulation by pathogens, cucumber plants increased lignin content, to a certain extent prevented the invasion of pathogens and expansion.2After pathogen infection, the soluble protein of leaf decreased by20%and the content of sucrose creased by43%. All these are because of the inhibition of leaf soluble protein transporting to shoot and soluble sugars to underground transport after pathogen infection. Meanwhile, soluble protein in root increased significantly. There are some phenomena that POD and other activity enhancements, MDA content increased, the formation of lignin after pathogen infection.3. The callose formation, will lead to catheter blockage and hinder the absorption of moisture, but it is not an important reason for the plants wilt catheter blockage.4. The FA wilt acid treatment will decline the cucumber root vigor and increased leaf and root conductivity. Especially the activity of cucumber root decreased by87.5%after1.5hour. All of these reflect the damage caused by the FA treatmens to the cell membrane, which increased the permeability of membrane, causing water spread out directly from the cells, and the emergence of the phenomenon that cucumber had wilt disease because of dehydration.