Regulation Of Foliar Application Of Sulfur-containing Amino Acids On Wheat Grain Quality

Nitrogen(N) and Sulphur(S) are essential nutrients for wheat and play significant roles in wheat yield and quality, especially with the use of nitrogen and sulfur fertilizer simultaneously. Wheat cultivars, Yangmai 16 and Lianmai 6 which are main upland cultivars in Jiangsu province, were selected in this study to investigate the effect of foliar application of sulphur-containing amino acid during grain filling stage on wheat quality traits. In addition, we used a peeling machine to study the response of sulphur-containing amino acid on the spatial differences of chemical components concentrations of wheat flour. Besides, further studies of wheat grain quality formation and regulation by fertilizer of wheat grain were investigated.1. Effect of foliar sulphur-containing amino acid on protein and its components concentrations of wheat flourSulphur-containing amino acid was applied as foliar sprays on wheat during grain filling stage. The effects of sulphur-containing amino acid on grain protein and its components concentrations of Yangmai 16 were more significant than Lianmai 6. Sulphur-containing amino acid had no significant effect on spikes and kernels in both cultivars, but reduced grain weight while the additional use with urea could mitigate this adverse impact. The concentration of grain protein and its components、GMP (Glutenin macro-polymer) and HMW-GS increased under high nitrogen level of Cys+Urea、Ser+Urea、 Urea, while these indexes also increased under the low nitrogen level treatments of Cys and Ser but the increase effect was lower than the high nitrogen treatments. Met and Met+Urea performed differently in two cultivars. The two treatments obviously improved the protein concentration、GMP content、total HMW-GS and individual HMW-GS contents of Lianmai 6, but not significantly in yangmai. No significant influence on grain protein content was found under the treatments of individual application of amino acid, but the additional use of urea approved the grain protein and its component contents, presenting the possible interaction effects bewteen amino acid and urea.2. The spatial differences of chemical components concentrations and quality traits of wheat flourWith the use of use a peeling machine, wheat grains of Yangmai 16 and Lianmai 6 were divided into five pearling fractions and flour from different layers were used to analyse the chemical composition and quality traits. The trend was consistent in two cultivars. From the outside to inside of wheat grain, starch content, amylose/amylopectin content, pasting properties and swelling power showed a gradual increase and then turned stable, the number of A-type and B-type starch granules、the average diameter of A-、 B-、 C-type starch particle size all raised first and reached the maximum in P4 layer but declined sharply in P5 layer. The affection trend in number of C-type was opposite. The content of protein, gliadin, glutein, GMP, HMW-GS, SDS-sedimentation, gluten increased first reaching the maximum in P2 layer then decreased. Albumin, globulin, Asp, Gly, Ala, Arg and Lys showed a gradual downward trend while the trend of ’other amino acid and total amino acid content was similar with the protein. Overall, the protein and its components contents were higher in the outer layer of grain and while the inner layer was mainly consisted of starch, resulting in maximum pastion properties in the inner layer.3. The effect of sulfur-containing amino acids on starch and protein traitsThe percentage of A-type starch granules, average particle size and the content of protein, gliadin, glutenin, total HMW-GS, amino acid composition, gluten, sedimentation value raised under the treatments of Ser+Urea and Cys+Urea. The increase on the protein and its components reached maximum in P3 of Yangmai 16 and P4 of Lianmai 6. The increase of GMP content in outer layers was more obvious than that in inner layer. Two cultivars showed different response under the treatment of Ser and Cys. The effect of application of amino acid and urea on wheat the grain chemical composition and quality traits was significantly stronger than indivial amino acid application.