Effect Of Nitrogen Application On Enzyme Activity,Root Physiological Index And Yield Of Different Maize Varieties

The corn varieties were studied through hydroponic and field experiments: Jidan 27,Zhengdan 958,Jidan 50,Liangyu 88,Liangyu 66,and Sidan 19,at different nitrogen levels.The effects of plant growth,dry matter weight,root morphology,leaf chlorophyll content,nitrate reductase(NR),leaf glutamine synthetase(GS),and leaf soluble protein content on the plant were evaluated to determine whether these indicators could be used as alternatives.The indicators of nitrogen-efficient maize provide theoretical basis and technical support for providing theoretical support for the establishment of new biofunctional identification system for nitrogen efficient maize.The results show:(1)In the field experiment,NR activity,GS activity,soluble protein content,and SPAD of different varieties of maize leaves differed depending on the level of nitrogen applied.When nitrogen was applied(N180),the NRs of high-efficiency corn varieties Jidan 27 and Zhengdan 958 were observed.The content of GS,soluble protein and SPAD were higher,and the low-efficiency varieties Liangyu 66 and Sidan 19 had lower indexes.The high-nitrogen absorption and dry matter accumulation of different organs in different growth stages were also high,but the difference between high-efficiency varieties was not significant.The root dry weight of Zhengdan 958 was the highest among different maize varieties,and the number of four single 19 was the smallest.With the increase of N application amount,the root morphology of high-efficiency cultivars increased.The yield of different maize varieties varies with the amount of nitrogen applied.Nitrogen application increases the yield of corn,and the yield and yield increase of high-efficiency varieties are relatively high.The contribution rate of nitrogen fertilizer,partial productivity,and agronomy of high-efficiency varieties Jidan 27 and Zhengdan 958 The efficiency and nitrogen use efficiency were higher,and the partial productivity and nitrogen use efficiency of inefficient varieties Liangyu 66 and Sidan 19 were lower.(2)Through hydroponics,the NR activity,GS activity,soluble protein content,and SPAD content of different varieties of corn at seedling stage were N1-0.04 mmo/L,N2-0.4 mmol/L,N3-2 mmol/L,N4-At 4 mmol/L,there are significant differences.There was a significant or highly significant positive correlation between different maize varieties and nitrogen supply levels.The root dry weight of the high-efficiency varieties of different maize varieties was the largest,and the nitrogen deficiency was too high.The root length,root surface area,and average of different corn varieties were significant.Root diameter,root volume,apical number,and bifurcation number have a great influence.(3)From the results of correlation analysis,in the field test,corn yield was positively correlated with GS,SPAD,NR,soluble protein,and SPAD at flowering stage,and there was no correlation with root morphology,and NR,GS,and soluble protein in leaves.There is a positive correlation between SPAD and SPAD.In the hydroponics experiment,there was a quadratic parabolic equation between different maize varieties and nitrogen levels,and there was a very significant positive correlation between NR activity and nitrogen supply levels in the nitrogen-efficient maize varieties Zhengdan958 and Jidan27.The leaf GS activity and nitrogen supply level reached extremely significant levels.There was a significant or extremely significant positive correlation between root morphology indicators.