Effects Of N Regulation On Quality, Grain Yield Of Winter Wheat And Its Physiological Basis

Under the condition of high organic matters (OM) soil, effects of nitrogen application amount on protein quality, processing quality, grain yield of winter wheat and its physiological basis were studied by using two strong-gluten wheat (SGW) varieties (Linyoul45 and Zhengmai9023) and two weak-gluten wheat (WGW) varieties (Ningmai9 and Baofeng949). Meanwhile, Effects of both the applying amount and date of nitrogen on protein quality and grain yield of wheat were studied by using CA 0206 (WGW). They were carried out at the experimental farm of Institute of Crop Sciences, Chinese Academy of Agricultural Sciences from 2004 to 2005. The main results were as follows:1. Effect of nitrogen regulation on protein quality of wheatResponse of protein quality of SGW and WGW to nitrogen application amount were similar. The contents of total protein, globulin, gliadin and glutenin all increased significantly with the amount of N-fertilizer added, but the effect of nitrogen application amount on albumin content was not remarkable. The difference of storage protein content of SGW and WGW was remarkable, but the difference of content of their soluble protein was not remarkable. The effects of nitrogen application amount on the percentage of each protein component content to total protein content were not remarkable. Percentage of each protein component content to total protein content was relative stable.Effects of nitrogen application amount on content of protein and its components of CA 0206 (SGW) were remarkable. Total protein, albumin and glutenin content in grain increased with the amount of N-fertilizer added;the maximum of globulin and prolamin were under middle N level, and their content would decent with N-fertilizer added continually. Effects of top-dressing nitrogen at different dates on total protein, albumin and prolamin content were remarkable.2. Dynamics of content of protein and its protein components in grain of wheatThe protein content showed a same "high-low-high" dynamic trend in Linyoul45 (SGW) and Baofeng949 (WGW) after anthesis. Protein content increased with the amount of N-fertilizer added in grain of Linyoul45 and Baofeng949 during grain filling stage, and protein content of Linyoul45 was higher than that of Baofeng949 under different N levels all the time. During the grain filling stage, the dynamic tendency of each protein component of Linyou145 and Baofeng949 was almost identical, and the characteristics of albumin accumulation showed descendingtendency;the change of globulin content was small;gliadin and glutenin accumulation showed an increasing tendency. Each protein component content increased with the amount of N added during whole grain filling stage.3. Response of processing quality characteristics of wheat to nitrogen application amountProcessing quality of wheat can be improved by applicating N-fertilizer. TW decreased with the amount of N-fertilizer added;Sedimentation value, wet gluten content, loaf volume and loaf score all increased with the amount of N-fertilizer added. Responses of processing quality characteristics of SGW and WGW to nitrogen application amount were different, and the difference of each quality characteristic was significant among varieties.4. Effect of nitrogen regulation grain yieldEffects of nitrogen application amount and stage of top-dressing nitrogen on grain yield were not remarkable in this experiment, of which higher soil properties was probably the reason.Wheat physiological basisChi content, N content and NRA all showed the parabola shape in changing pattern in flag leaf. The dynamic tendencies of Chi content of Linyoul45 (SGW) and Baofeng949 (WGW) were the same, but the dynamic tendencies of N content and NRA of two quality type wheats were different. Chi content, N content and NAR in flag leaf all increased with the amount of N-fertilizer added.