Effects Of Reduced Nitrogen Application On Grain Filling Characteristics And Quality Of Spring Wheat Under Drip Irrigation

The traditional drip irrigation spring wheat planting model is a high-yield and high-yield planting concept,which leads to problems such as excessive application of nitrogen fertilizer,low absorption efficiency of nitrogen,and environmental pollution.Therefore,under the condition of reduced nitrogen application,it is of great significance to study the changes of grain filling characteristics and quality of spring wheat with drip irrigation to improve the yield and quality of Xinjiang wheat.Therefore,from the perspective of wheat physiological and biochemical changes,this paper studies the grain filling characteristics of spring wheat under drip irrigation,the changes of key enzyme activities and accumulation during sucrose to starch conversion,and the key to protein accumulation under the treatment of root nitrogen reduction.The changes in enzyme activity,etc.,explored the grain characteristics of the main content,and explored the technical ways to improve the yield and quality potential and nitrogen fertilizer utilization rate by distilling irrigation of spring wheat through nitrogen-saving cultivation.Exploring the optimal nitrogen application method,in order to provide scientific basis and technical support for further stabilizing spring wheat yield and improving nitrogen utilization efficiency in Xinjiang.The main conclusions are as follows:1.The grain filling characteristics of spring wheat under drip irrigation,the dynamic changes of dry matter accumulation in stems,sheaths,leaves,wheat ears and grains under different treatments decreased with the decrease of nitrogen application rate,then increased and then decreased.Xinchun 49 Then it shows a trend of increasing first and then decreasing.The results showed that the changes of dry matter accumulation in stems,leaves,wheat ears and grains of Xinchun No.38 under different treatments were the best under N3(250 kg·hm^-2)treatment,and N3(250 kg·hm^-210 days after flowering).Other treatments under were 9.6%to 67.4%,6.4%to 38.9%,4.4%to 34.6%,and 1.4%to 11.00%,respectively.The changes of dry matter accumulation in stem,sheath,wheat,wheat and grain of Xinchun 49 were the best under N3(250kg·hm^-2)treatment,and the stem was treated under the treatment of 275 kg·hm^-2 for 10 days after flowering.The dry matter accumulation of sheath,leaf,wheat and grain was 5.7%⁵4.1%,2.7%²0.3%,6.2%²9.2%and 13.7%²6.8%higher than other treatments,respectively.Correlation analysis between the grouting parameters and 1000-grain weight showed that the two varieties showed negative correlation with T,T1,T2 and T3,and positive correlation with Tmax,Rmax,R,R1,R2 and R3.There was a significant positive correlation between Xinchun 38 and the filling rate and average filling rate in different stages.Xinchun 49 was significantly negatively correlated with the duration of the filling and the duration of the fast increasing period.The duration of the fast increasing period and the duration of the increasing period were significantly negative.relationship.2.Under different nitrogen application rates,the appropriate nitrogen application rate can increase the activity of nitrogen and carbon metabolism enzymes in spring wheat under drip irrigation.The nitrogen application rate is too high or too low,which is not conducive to enzyme activity.It was found that the activity of wheat grain enzyme was the best under the treatment of N3(250kg·hm^-2),and the activity of wheat grain enzyme was the best under the treatment of N2(275 kg·hm^-2)..With the decrease of nitrogen application rate,the activities of sucrose synthase?SS?,ADPG pyrophosphorylase?AGPase?and soluble starch synthase?SSS?in wheat grains of two different varieties showed their progress along the growth process.The unimodal curve,the peak appeared in the 30 days after flowering,and the sucrose synthase?SS?activity,ADPG pyrophosphorylase?AGPase?,soluble starch synthesis in wheat grains treated by N3(250kg·hm^-2)in Xinchun 38 The enzyme?SSS?activity was 2.7%to 31.6%,0.9%to 8.2%,0.3%to 5.3%higher than other treatments,and sucrose synthase in wheat grains treated with N2(275 kg·hm^-2)in Xinchun 49?SS?activity,ADPG pyrophosphorylase?AGPase?,soluble starch synthase?SSS?activity was6.9%to 30.1%higher than other treatments,2.4%to 9.4%,4.2%to 15.9%.The sucrose synthase activity of wheat grain in Xinchun No.38 and Xinchun No.49 was increased under the treatment of N3(250 kg·hm^-2)and N2(275 kg·hm^-2),respectively,and the assimilation in post-anthesis seeds was improved.Transportation,resulting in a decrease in sucrose content in wheat grains.Appropriate nitrogen application rate can increase the activity of adenosine diphosphate glucose pyrophosphorylase and soluble starch synthase in wheat grains,which is beneficial to the accumulation of starch in grains.With the decrease of nitrogen application rate,the activity of glutamine synthetase?GS?,glutamate pyruvate transaminase?GPT?and nitrate reductase?NR?decreased in two different wheat varieties.The activity of glutamine synthetase?GS?,glutamate pyruvate transaminase?GPT?and nitrate reductase?NR?in wheat grains treated with N3(250 kg·hm^-2)was 11.0%higher than that of other treatments.21.5%,2.2%⁵.5%,8.2%⁴8.8%,glutamine synthetase?GS?and glutamate pyruvate transaminase?GPT?in wheat grains treated by N2(275kg·hm^-2)in Xinchun 49 The nitrate reductase?NR?activity was 1.8%to 12.8%,1.8%to 14.8%,and 8.8%to 45.7%higher than other treatments.3.The appropriate nitrogen application rate at the different filling stage can not only increase the total protein content of the grain,but also increase the protein yield.With the decrease of nitrogen application rate,the effects of different nitrogen application rates on sucrose content,starch content,protein and its components in wheat grains were different.Xinchun No.38 performed optimally under N3(250kg·hm^-2)treatment,and increased by 10.7%⁵6.1%,1.6%⁸.6%,4.2%²5.2%,respectively,compared with other treatments.Xinchun 49 was in N2(275 kg·hm^-2)performed optimally under treatment and increased by 5.9%to 56.6%,1.9%to 7.5%,and 6.5%to 20.9%,respectively,compared with other treatments.In the treatment of N3(250 kg·hm^-2),the globulin,prolamin,glutenin and albumin in wheat grains were increased by 51.7%,34.5%,12.8%and 28.9%,respectively,compared with N5;Xinchun 49 was Under the treatment of N2(274 kg·hm^-2),the globulin,prolamin,glutenin and albumin in wheat grains were increased by53.0%,28.3%,23.3%and 34.8%,respectively,compared with N5.The grain yield of Xinchun No.38 and Xinchun No.49 wheat decreased firstly and then decreased with the decrease of nitrogen application rate.The 1000-grain weight,the number of panicles and the grain of the grain of Xinchun No.38 and Xinchun No.49 were respectively in N3.,N2 processing to achieve optimal.The nitrogen application rate of Xinchun No.38 and Xinchun No.49 wheat reached the maximum at 250kg·hm^-2 and 275 kg·hm^-2,respectively,which was 1.3%³5.5%and 1.4%³4.7%higher than other treatments.After fitting,the nitrogen application rate?x?and the yield?y?are quadratic parabolic functions,y ₃₈=-0.0147x²+10.222x+5415.6,y ₄₉=-0.0025x²+6.846x+5239.6,and R² is 0.9112,0.9788.