Different Nitrogen Levels On Potato Late Blight Resistance Physiological And Biochemical Indexes

From the effective utilization of potato ’s own defense mechanisms to improve the capacity of resistance to this new idea,Through the reasonable fertilization,to meet the plant growth nutrients at the same time,improve the plant’s own health status,to improve the plant’s own resistance to disease control plant disease prevention technology for environmental protection,sustainable plant protection implementation,organic green food production determines the future direction of agricultural development,use the greenhouse nitrogen test,using the method of comparative physiology,resistance（tolerance）to late blight of 3 different potato varieties as materials,systems analysis of different levels of nitrogen fertilizer on Potato Resistant metabolic effects,and after uninfected pathogenic infection and vaccination of late blight resistant potato（tolerance）in different nitrogen application,susceptible varieties of late blight,the effect of cell defense enzymes,cell wall hydrolase activity and resistance to physical differences and changes,to clarify the nitrogen on Phytophthora infestans（Phytophthora.infestans）resistance physiological characteristics.The results show that: 1.From the nitrogen level,with the increase of nitrogen amount,in potato leaves the cell defense enzymes,cell wall hydrolase activity has increased,when too much nitrogen amount(180kg·hm^-2),the activity of various enzymes decreased or rendered unstable state,description of nitrogen fertilization effects on potato leaves of various enzyme activity.No pathogen infection and pathogen infection,in the nitrogen level is 135kg·hm^-2,in the leaves of PPO,POD,PAL,CAT,chitinase,amylase and β-1,3-glucanase activity than other nitrogen level,and the resistant cultivars was higher than that of the susceptible cultivar.Description of Phenolics Metabolism in potato disease-resistance mechanism is the important component of nitrogen,and played a supporting role.2.Using spectrophotometer determination of leaf under different nitrogen levels of phenols content.The results show that,without the pathogen infection in leaves of total phenolics,flavonoids,chlorogenic acid content in the nitrogen level is 135kg·hm^-2 were significantly higher than other nitrogen level,and the resistant cultivars was higher than that of the susceptible varieties inoculated with Phytophthora infestans,treatment resistant varieties of total phenolics,flavonoids,chlorogenic acid content was also higher than those in susceptible varieties,and significant.3.No resistant cultivars or susceptible varieties,when nitrogen application for 135kg·hm^-2 level of soluble sugar content is higher than other nitrogen content.Soluble sugar higher cell loss,the less likely,the survival possibility is larger,the stronger the resistance.After inoculation,resistance of cultivars and susceptible varieties of soluble sugar content in different nitrogen levels increased,but when the quantity of nitrogen fertilizer is 135kg·hm^-2 level,with the inoculation time prolonged,disease-resistant varieties showed remarkable.4.From the nitrogen level,different levels of nitrogen fertilizer on potato late blight is significantly influence.No nitrogen treatment morbidity to a lesser extent,the yield is low;with the increase of nitrogen application,the extent of the disease increased slightly,but the yield with the increase of nitrogen amount is increased;when the nitrogenous amounts to 135kg·hm^-2 level,the incidence to a lesser extent,yield is very high in nitrogen;In the nitrogenous amounts to 180kg·hm^-2 level,disease severity significantly heavier,also because of disease severely restrict result in decreased production.It can be seen that,regardless of disease resistance varieties or susceptible varieties,nitrogen after exacerbation of potato late blight trend,but in moderate nitrogen application case of the disease manifested lesser,only a lot of nitrogen fertilizer can lead to significant exacerbation of disease.The incidence of resistant varieties is significantly lower than that in susceptible cultivars.From the above results can were seen,in a certain level of nitrogen fertilization,with the increase of nitrogen amount,cell defense enzymes,cell wall hydrolase activity,content of phenolic substances increases,when the amount of nitrogen level for 135kg·hm^-2,strong resistance to diseases,high yield;when the amount of nitrogen(higher level 180kg·hm^-2),resistance decreased,increased incidence,output falls.Therefore,from the perspective of resistance,to control at an optimal level of nitrogen.