Effect Of Exogenous Of Carbon And Nitrogen Nutrition At Post-anthesis On Quality Of Spring Wheat

The objective of this study was to investigate the effects of exogenous carbon (C) andnitrogen (N) nutrition on the carbon and nitrogen balance between source and sink organs atpost-anthesis stage and on the grain quality of spring wheat. We used two spring wheat varietiesKehan19(KH19) and Longmai33(LM33) as the study objects and sucrose and urea was sprayedwith three different concentrations on the leaves after full heading. Nitrogen metabolic activity,carbon and nitrogen metabolism interaction, and the response mechanism of these metabolismsto exogenous carbon and nitrogen regulation were monitored by determination of the changesin carbon and nitrogen metabolism of photosynthesis and grain quality. The results indicated asfollows:1. The exogenous carbon and nitrogen improved the nitrogen content and further increasedthe gluten content during the grain formation stage. This response was found to be moresignificant in KH19than in Longmai33. In KH19, a5%sucrose and2%urea treatment increasedthe wet gluten content by28.2%and37.5%, respectively. The interaction of carbon and nitrogenhad no significant effect on dough development time, but exogenous nitrogen increased the flourabsorption and dough stability time. Different concentrations of carbon and nitrogen havedifferent effects on processing the dough extension property. Overall, the extension area andanti-extension resistance were increased by exogenous C and N. Exogenous carbon has asignificant influence on the increase of anti-extension resistance. Generally,5%sucrose and2%urea is more conducive for improving wheat grain yield and quality.2. The flag leaf, as the source organ, has the highest nitrogen content and the most activenitrogen metabolism during the grain formation stage. Foliar application of5%sucrose and2%urea can improve the nitrogen content of source organs at wheat grain filling stage. Meanwhile,the above treatments can increase the nitrogen translocation amount from mature leaf sheath andinternodes. In total, both exogenous nitrogen and exogenous carbon had a positive effect onnitrogen accumulation in grains, and nitrogen metabolism of source organ is greater than thecarbon treatment, while carbon treatment is more conducive to transit and nitrogen and carbontreatment conducive to grain nitrogen accumulation.3. As an exogenous carbon treatment,5%sucrose significantly improved KH19and LM33albumin content by14.5%and25.2%than the control, respectively. The exogenous nitrogentreatment (2%urea) increased globulin content by22.0%and20.1%, increased glutenin contentby5.0%and7.3%, gliadin content increased by16.0%and11.0%. Exogenous nitrogentreatment significantly reduced the insoluble protein content, by26.1%and44.2%, respectively. Exogenous carbon and nitrogen treatments promoted albumin and glutenin, thereby increasingthe wet gluten content.4. The1000-grain weight was increased, accompanied with the exogenous carbon andnitrogen concentrations increasing. It was increased by0.9%~9.3%in the higher concentrationcarbon and nitrogen treatment (5%sucrose and2%urea), which improved grain plumpness,thereby increased yield. In the two years, in5%sucrose treatment, yield of LM33was increasedby6.9%and15.3%, and yield of KH19was increased by10.1%and14.0%, respectively. In2%urea treatment, yield of LM33was increased by15.8%and10.2%, and yield of KH19wasincreased by16.8%and0.9%, respectively.