The Effects Of Nitrogen, Phosphorus, Potassium On Starch Quality In Wheat With Different Gluten Type

The experiments was taken from 2002 to 2004 in order to mainly studied the synthesis and accumulation dynamic of the grain water-soluble carbohydrate, grain starch and grain starch component in wheat with different gluten type ( the strong-gluten type wheat Zhengmai9023, the medium-gluten type wheat Wenmai4,the weak-gluten type wheat Yumai50), analyzed the relationship of key enzymes involving in starch synthesis and sucrose content with starch content, discussed the regulating effects of nitrogen, phosphorus and potassium on the grain starch of Zhengmai9023 and Yumai50.The main results were as follows.1. The synthesis and accumulation of the grain total soluble sugar content, grain starch and grain starch component and the grain starch characteristics in wheat with different gluten type was studied. The results showed that the sucrose content in grains of wheat with different gluten type dropped constantly during the grain filling stage, and the highest content appeared on the 6th day after anthesis ( DAA). The glucose content had the same tendency with sucrose content, but grain glucose mainly existed in early grain filling stage, and the glucose content in Wenmai4 was the highest and least in Yumai50. The changes of grain fructose content were as follows: the fructose content in Zhengmai9023 peaked on the 6th DAA, while in Yumai50 and in Wenmai4 peaked on the 6th day and then descended rapidly, but rose slightly on the 24th DAA and declined immediately. The amylose , amylopectin and starch content in grain rose gradually after anthesis and showed "S"type curve change. The content accumulating rate of amylose , the amylopectin and starch content accumulating rate appeared their maximum on the 20-25th DAA. The ratio of amylose to amylopectin showed "V"type curve change. The peak viscosity, trough viscosity and final viscosity in medium- gluten type wheat was higher than those in strong- gluten type wheat, and those in weak-gluten type wheat was lowest. While the orders of breakdown in wheat with different gluten type were the weak-gluten type wheat >the s'trong- gluten type wheat> the medium- gluten type wheat, and the setback orders were the strong- gluten type wheat> the medium- gluten type wheat> the weak-gluten type wheat.