Under High Temperature Stress After Anrthesis Nitrogen Dressing Ratios Mechanism Of Starch Quality And Yield Of Spring Wheat Research

Use Ningchun 4 and Ningchun 47 as the test materia, in the way of bonsai, setting nitrogen dressing ratios and temperature as two experimental factors, studied the impact of the quality and yield on spring wheat starch under stress of high temperature after anthesis and discuss the mitigation of nitrogen dressing ratios on high temperature stress to the adverse impact of spring wheat. The results showed that:1、Ningchun 4 and Ningchun47 had same trends, compared with the normal temperature treatment, in late filling high temperature stress lead to leaf area index (LAI) decreased, chlorophyll content decreased significantly, integrated fluorescence parameters PI, photosynthetic parameters and photosynthetic rate, reduced dry matter accumulation and reasonable application of nitrogen fertilizer can alleviate hot hazards. Under high temperature conditions, nitrogen dressing ratios N2 (4:6) in 20d after anthesis, leaf area index of (LAI) was the highest, compared with other treatments, increased by 19.07%、56.67%、50.79%、60.19%, and the SPAD value, dry biomass accumulation optimum nitrogen treatment were:N2 (4:6) and N1 (3:7); integrated parameter PI fluorescence of N1 (3:7) increased by 15.27%、25.05%、31.29%、21.63% than other nitrogen treatments; net photosynthetic rate of Nl (3:7) was increased by 50%、58.18%、62.73%、73.64% than other nitrogen treatments.2、High temperature resulted Ningchun 4 Ningchun 47 protection activity decreased in late filling, MDA concentration increased, the increase in membrane lipid peroxidation, and nitrogen application could increase the activity of protective enzymes, reduced MDA content, reduce membrane damage. Ningchun 4 under high temperature conditions, nitrogen dressing ratios N2 (4:6) in 25d after anthesis SOD activity was the highest, increased by 11.12%-49.34% than other nitrogen treatments; POD activity of N2 (4:6) increased by 4.39%-56.67% than the other treatments; compared with other treatments,CAT activity of N1 (3:7) increased by 34.46%-46.05%; and N4 (7:3) of MDA content decreased by 5.18%-24.20% than other treatments,Ningchun 47 and Ningchun 4 had same trends.3、Ningchun 4 and Ningchun 47 under high temperature stress conditions, grain weight, grain starch content and starch to form a key enzyme, significantly reduced, grouting fast, less accumulation of dry matter, and senescence in advance, impact the improvement of production and reasonable nitrogen dressing ratios can increase spring wheat yield and starch quality. From the view of yield components, grain weight greatly impact on grain yield,under the high temperature and normal temperature conditions, pre-nitrogen fertilizer to Ningchun 4 and Ningchun 47 of grain weight were not obvious, and under stress of high temperature, the grain weight、grain starch content and form a key enzyme in starch processing were lower than normal temperature treatments, Ningchun 4 of grain weight decreased 1.40%-27.26% than other treatments, biological yield decreased 13.64%-44.59%; Ningchun 47of grain weight decreased 0.53 %t-28.36%, biomass yield decreased 23.93%-93.83%, nitrogen dressing ratios N2 (4:6) of grain weight declined the smallest. Therefore, nitrogen dressing ratios N2 (4:6) and appropriate nitrogen after the shift can relief the effect of high temperature in late filling on spring wheat was obvious.