The Research Of NR With NiR Coupling Function And Regulation Of Nitrogen Assimilation In Sugar Beet

In this dissertation,shuangfeng8of sugar beet was seleeted as experimental sample，andexperiments were made in NEAU.Experimental factors were as follows: NO3-、NO₂^--、NH₄⁺,pH.In experiments the quadratic rotation-orthogonal combination1/2design wasadopted.We comprehensively and systematieally stodied on dynamic changes andregulation approaches of key enzymes of inorganic nitrogen assimilation metabolism,photosynthetic rate （Pn） and main products. Nitrate reductase （NR） and nitrite reductase（NiR） coupling relationship, analysis on nitrogen assimilation and photosynthesis,accumulation of sucrose, total nitrogen content, Illuminates the relationship of sucrosemetabolism and inorganic nitrogen assimilation of sugar beet. Reveals the control effect ofNO₃^-、NO₂^-、NH₄⁺and pH on sugar beet yield and quality, inorganic nitrogen assimilationand accumulation of sucrose. This study improved the beet NR, NiR coupling relationstheory study, can be used as identification, evaluation of germplasm resources and settingreasonable proportion, levels and time of nitrogen..Results of this experiment are asfollowing:1. At different stages regulation effects of NO₃^-、NO₂^-、NH₄⁺, pH on NRA,NiRA,photosynthetic rate, total nitrogen and Sucrose content of Root were different, There wereobvious interactions between two factors, and in interaetion the main factor were different.At the same time the contributor of four treatments on Determination of five indicatorswere different. and interaction between two factors, the interaction of five factormeasurement indicators play a leading role, at the same time in different growth period,.Nitrate nitrogen and ammonium nitrogen to all measurement indexes has high contribution,the contribution rate of nitrate to the NRA,NiRA, higher pH value of the contribution rateis relatively low.2. NR and NiR active all showed bimodal curve change.NR activity of leaf reached thepeak on June22, and the second peak appeared on August26. NiR activity of leaf reachedthe peak on June6, and the second peak appeared on August26. The NRA and NiRA indynamic change trend in the whole stages with phenomenon, increase with the decrease intotal fertility period basic maintain positive correlation, that the coupling effect exists.3. Photosynthetic rate show unimodal curve change, peak appeared in the August12th.Photosynthesis and the NR, NiR basic maintain positive correlation and dynamic ruleaffected by inorganic nitrogen metabolism in the whole stages.4. Sucrose content showed a trend of linear growth, from June6, the lowest, in addition tothe August26is slightly lower, were keep rising trend in the whole stages, until the sugaraccumulation period still remain high level. Total nitrogen content of root showed bimodal curve changes, reached the peak on June6, and the second peak appeared on August26.Total nitrogen content and sucrose content root maintain negative correlation in the wholestages.5. Sugar beet birth prophase, the NRA, NiRA, photosynthetic rate and root sucrose contentbasic maintain positive correlation; Birth later period, the NRA, NiRA, photosynthetic rateand root total nitrogen content to maintain positive correlation basically.6. Different processing factors on the quality of the sugar beet production. Contributionrate of yield sequence are: NO₃^->NH₄⁺>pH>NO₂^--, contribution rate of sugar yield sequence is:NO₃^->NH₄⁺>NO₂^-->pH.