Expression Characteristics Of Key Enzymes In Nitrogen Metabolism And Effects On Nitrogen Metabolism In Different Types Of Melon Grafted Stock

Nitrogenous fertilizer is one of the main agricultural inputs,increasing rapidly in our country,and having already become the largest country in the world.The excessive use of nitrogen fertilizer does not conform to the sustainable development strategy of facility vegetables in our country.What’s more,there is no study about high utilization of fertilizer for melon grafting stock selecting.we screen out different types of grafting combination of melon and watermelon of high utilization nitrate nitrogen by the different features on nitrate nitrogen absorption.The experiment was conducted in type Liaoshen I greenhouse,with the melon seeding by grafting in 5th leaf stage for treatment,and the own root melon seeding as control.The contents of the experiment were divided into two parts.First of all,determination of nitrate nitrogen content、nitrate reductase activity and nitrate reductase gene expression by the existing grafting combination,so as to make sure grafting can improving scion nitrate nitrogen utilization.At the meanwhile,determination of nitrate nitrogen content 、 nitrate reductase activity and nitrate reductase gene expression of different rootstock,so as to make sure the different features of nitrate nitrogen uitilization of different rootocks.Then,the rootstocks with better nitrate nitrogen uitilization were grafted with different kinds of scions.So it can screened out the grafting combination with high nitrate nitrogen absorption by determining nitrate nitrogen content、nitrate reductase activity and gene expression of some key enzymes in nitrogen assimilation process of different grafted seeding,To make sure that when the same rootock was grafted with different kingds if scion,whether the grafted seeding of the level for nitrate nitrogen utilization is the same as scion,or it depends on the interaction between rootstock and scion in the.And when the same scion was grafted with different rootocks,whether the grafted seeding of the level for nitrate nitrogen utilization is the same as scion,or it depends on the interaction between rootstock and scion in the.The results are as follows:1.Differences in nitrate nitrogen utilization of different crops:Under the same cultivation conditions,nitrate nitrogen content 、 nitrate reductase activity and nitrate reductase gene expression in different scion varieties and rootstock varieties as well as existing grafted combinations were different at the stage of 5th leaves.Based on this,the cultivars with higher nitrogen utilization were screened for grafting.In conclusion,among melon varieties,’hualei’ had the strongest nitrogen utilization capacity,while ‘xiangfei’ had the weakest nitrogen utilization capacity.Among watermelon varieties,’qianpujincheng’ had the strongest nitrogen utilization capacity,while ‘miduo’had the weakest nitrogen utilization capacity.Among the pumpkin varieties,‘zhenyou45’had the strongest nitrogen utilization capacity,and ‘shengzhen1’was second.Among the gourd varieties,‘hanguozhongzi’had the strongest nitrogen utilization capacity.The nitrate nitrogen content、nitrate reductase activity and nitrate reductase gene expression in functional leaves of grafted seedings were increased compared with scion seedlings.Indicating that the ability of nitrogen in functional leaves of scion was enhanced by rootstock grafting.2.Differntial expression of nitrogen assimilation in leaves of different grafting seedings:In the same scion with different rootstock of two groups of different grafting seedings,the grafting seedling with the higher nitrogen utilization using was higher also of the nitrate content、nitrate reductase activity and NR,GS,GDH gene expression.Showing a higher uniformity.It is conclusion that the higher nitrogen utilization capacity of rootstock,the higher nitrogen utilization capacity of grafted seedling in the same condition of scion.In the same rootstock with different scion of two groups of different grafting seedings,the grafting seedling with the higher nitrogen utilization using was not necessarily the higher of nitrogen utilization,show a lower uniformity,more complex.It is conclusion that the ability of grafting seedling of nitrogen utilization depends on the interaction between rootstock and scion in the condition of the same rootstock different scion.3.Screening the higher grafting combination of nitrate nitrogen utilization:Under the same cultivation conditions,there were significant differences of different grafting seedling’s nitrate nitrogen utilization in 5th leaf stage.Screening the higher grafting combination of nitrate nitrogen utilization by nitrate content、nitrate reductase activity and NR,GS,GDH gene expression.Among the melon grafting seedlings,combination of‘hualei+zhenyou45’had the strongest nitrate nitrogen utilization.Among the watermelon grafting seedlings,combination of‘qianpujincheng+zhenyou45’ had the strongest nitrate nitrogen utilization.