Effects Of Water And Nitrogen Management On Yield And Quality Of Strong Gluten Wheat And Its Physiological Mechanism

There is a structural imbalance in wheat production in China.The production of strong gluten wheat can not meet the needs of society.Hebei Province is the dominant production area of strong gluten wheat,which is of great significance to the production of strong gluten wheat in China.However,there are some problems in production,such as water scarcity,low water and N use efficiency,uncoordinated yield and quality.In order to clarify the effect of water and nitrogen management on the yield and quality of strong gluten wheat,explore the best management measures for strong gluten wheat production in Hebei Province,and promote the development of strong gluten wheat production in Hebei Province.In this study,the wheat variety Gaoyou 2018 and Jimai U80 were used as experimental materials in two wheat seasons from 2020 to 2022.Three irrigation levels of under the conditions of supplementing the soil relative water content of 0-60 cm soil layer under treatments 65%(W1),75%(W2),85%(W3)at jointing stage and flowering stage,three nitrogen application treatments of under the condition of 120 kg·hm-2 nitrogen fertilizer,pure nitrogen 90 kg·hm-2(N1),120 kg·hm-2(N2),150 kg·hm-2(N3)were applied at jointing stage.The regulation effect of water and nitrogen management on the yield and quality of strong gluten wheat was studied,and the physiological mechanism of the effect of water and nitrogen management on the yield and quality of strong gluten wheat was explored,in order to provide theoretical basis for the high yield and high efficiency production practice of strong gluten wheat in Hebei Province.The main results are as follows:(1)Water and nitrogen management had a significant effect on the yield of strong gluten wheat.Under W1 treatment,the grain yield of Gaoyou 2018 increased with the increase of topdressing nitrogen.Under W2 and W3 treatments,the grain yield increased first and then decreased with the increase of topdressing nitrogen,with the highest under N2 treatment.Under N1 treatment,grain yield increased with the increase of soil relative water content.Under N2 and N3 treatments,grain yield reached the highest under W2 treatment.Under the same irrigation treatment,the grain yield of Jimai U80 increased with the increase of topdressing nitrogen,and the highest was N3 treatment,but the difference between N2 and N3 treatments was not significant.Under the same nitrogen topdressing level,the grain yield increased first and then decreased with the increase of soil relative water content,and the difference between W2 and W3 treatments was not significant.The yield of Gaoyou 2018 was the highest in W2N2 treatment,and the two-year test yield was 8316.00 kg·hm-2 and 8910.07 kg·hm-2,respectively.The yield of Jimai U80 was the highest in W2N3 treatment,and the two-year test yield was 8869.97 kg·hm-2 and 9384.50 kg·hm-2,respectively,which was not significantly different from W2N2 treatment.When the relative soil water content was 75%,the spike number and grain number per spike of strong gluten wheat could be effectively increased,and higher yield could be obtained.Increasing the amount of nitrogen topdressing at jointing stage can increase the number of spikes and grains per spike,but reduce the 1000-grain weight.Water and nitrogen management mainly increased yield by increasing the number of spikes and grains per spike of strong gluten wheat.(2)The dry matter accumulation of the two varieties increased first and then decreased with the increase of soil relative water content,and the response of dry matter accumulation of different varieties to nitrogen was different.The dry matter accumulation of Gaoyou 2018 increased with the increase of nitrogen application under W1 treatment,and increased first and then decreased with the increase of nitrogen application under W2 and W3 treatments.The dry matter accumulation of Jimai U80 showed a continuous increase with the increase of nitrogen application,and the N3 treatment was the highest.There was no significant difference between N3 and N2 under W3 treatment.The dry matter accumulation of Gaoyou 2018 was the highest in W2N2 treatment,and that of Jimai U80 was the highest in W2N3 treatment.The dry matter accumulation after anthesis and the contribution rate to grain of W2N2,W2N3 and W3N2 treatments of two strong gluten wheat varieties were higher.(3)Compared with W1 and W3 treatments,W2 treatment increased the activities of nitrate reductase(NR)and glutamine synthetase(GS)in flag leaves and grains,increased the content of free amino acids in flag leaves and grains,the content of soluble protein in flag leaves,and increased the nitrogen accumulation after anthesis and the contribution rate to grain nitrogen.With the increase of nitrogen topdressing at jointing stage,the nitrogen metabolism enzyme activity of Gaoyou 2018 increased first and then decreased,while that of Jimai U80 continued to increase.The nitrogen metabolism enzyme activity of Gaoyou 2018 was the highest under W2N2 treatment,and that of Jimai U80 was the highest under W2N3 treatment.Flag leaf NR,AA,and grain NR,AA have a significant impact on yield,while flag leaf GS and grain GS have a significant impact on quality.Flag leaf NR and grain NR affect quality by affecting flag leaf GS and grain GS.(4)With the increase of irrigation amount,the content of grain protein,prolamin and glutenin decreased,albumin increased first and then decreased,and globulin continued to increase.The albumin of Jimai U80 continued to increase with the increase of irrigation amount,and other indicators were the same as those of Gaoyou 2018.With the increase of nitrogen application rate,the protein content increased first and then decreased.Under the same irrigation conditions,the wet gluten content and sedimentation value of Gaoyou 2018 increased first and then decreased with the increase of topdressing nitrogen,and showed the maximum value under N2 treatment.Under the same nitrogen treatment,the settlement value was the highest in W1 treatment.Under the same irrigation conditions,the wet gluten content and sedimentation value of Jimai U80 increased with the increase of nitrogen application rate,and the value of N3 treatment was the largest.The significant difference between N3 and N2 treatments was different between years.Under the same nitrogen treatment,the contents of wet gluten and sedimentation value were the highest in W1 treatment.The protein content,sedimentation value and wet gluten of the two varieties were the highest in W1 treatment,followed by W2N2 and W2N3.The dough formation time and stability time increased first and then decreased.Gaoyou 2018 showed the highest W2N2,and Jimai U80 showed the highest W2N2 and W2N3.In summary,appropriate water and nitrogen management can increase the accumulation and transport of matter,enhance the activity of NR and GS enzymes in flag leaves and grains,promote nitrogen assimilation,increase the free amino acid content and soluble protein content in flag leaves,increase the grain yield and protein yield of strong gluten wheat,and improve the quality.Under the condition of 75%of soil relative water content at jointing and flowering stages,120 kg·hm-2 of pure nitrogen applied as base fertilizer and 120 kg·hm-2 of pure nitrogen applied as topdressing at jointing stage,it was the best combination of water and nitrogen to achieve the simultaneous improvement of yield,quality and resource efficiency of strong gluten wheat.