| The effects of nitrogen and sulphur on grain protein accumulation and parameters of quality were studied by six cultivars in spring wheat differing in quality. The results are summarized as follows:The application of nitrogen and sulphur have no influence on dynamic accumulation of grain protein in spring wheat differing in HMW-GS composition, but influenced accumulative speed and final content of grain protein accumulation. With high nitrogen application (N^g), the protein content in genotypes differing in quality was increased by the application of sulphur, especially to the cultivars with high grain protein, but the amount of sulphur should not be too large. The study indicated that whether the sulphur could have effect or not depend on the level of nitrogen application. Under the condition of higher level nitrogen, sulphur enhance the accumulation of grain protein in genotype with high grain protein and good quality. However little effect was found in the genotype with low grain protein and poor quality. The cultivars with HMW-GS composition 2+12 can get higher level of grain protein content in the treatments of 60kg/hm2 nitrogen and optimum amount of sulphur application and the same in cultivars with HMW-GS composition 5+10 with 128kg/hm2 nitrogen application and some amount of sulphur application.The LMW glutenin aggregation and the HMW glutenin aggregation were found 5th day and 15th days post anthesis in spring wheat differing in HMW-GS composition respectly. Then increased in treatment of N^g, sulphur can accelerate the accumulation of HMW glutenin aggregation and sufficient amount of sulphur is necessary for high level of HMW glutenin aggregation accumulation. For most cultivars, the content of LMW glutenin aggregation was increased in both sulphur application combined with 60kg/hm2 or 128kg/hm2 nitrogen, and the effect in 128kg/hm2 nitrogen treatment is better than that of 60kg/hm2 nitrogen supplying. It meant that higher nitrogen application is propitious to the accumulation of LMW glutenin aggregation. Early and quickly accumulation of HMW-G aggregation, NE7742 has higher amount of HMW-G aggregation.The high grain protein content in good quality cultivars with different type of HMW-GS 2+12 and 5+10 have the same accumulation patterns of HMW-G aggregation, and higher-3-ISJCffig 2002nitrogen and optimum amount of sulphur result in higher content of final HMW-G aggregation.The application of sulphur influenced the wet gluten content and SDS-sedimentation value in level of nitrogen treatment. In high nitrogen application treatment, the wet gluten and SDS-sedimentation value in cultivars both high grain protein content -good quality and low protein -poor quality could be increased by sulphur, but it is much better for the cultivars with high grain protein content and need more higher sulphur amount of application. In lower nitrogen (N6o) treatment, the wet gluten content was decreased and increased in SDS-sedirnentation value in all cultivars except LiaolO. Sulphur could bring its role into play and improved the protein quality under the condition of sufficient nitrogen application. It meant that nitrogen application would be the factor limit sulphur effect on protein processing quality.The integrated quality criteria could be improved in treatment of sulphur amounts ranged form 25~75kg/hm2 with high nitrogen appIication(Nns), and the treatment N^sSvs was the best in both cultivars NE7742 and Roblin. However, the treatment NngSas-so was good for cultivar NKH9. It meant that under high-nitrogen application condition, higher sulphur amount of application was necessary for high protein and good quality cultivar NE7742 and Roblin than that of NKH9, the low protein content and poor quality condition.The total content of amino acid and sulphur -amino acid in grain of cultivars with HMW-GS composition both 2+12 and 5+10 were increased by sulphur application under the condition of high nitrogen level, and the positive c...
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