Effect Of Nitrogen Application On Forming And Accumulation Of Carbohydrate In Spring Maize

This experiment utilized high starch maize SIDAN19, common maize NEAU250, good quality protein maize FENGHE10 as materials, studied on accumulation and forming regularity of carbohydrate in the developing spring maize gains, the research indicated that key enzymes had controlled sucrose content in process of sucrose synthesis, and compare with the difference of different varieties. The study showed that nitrogen application rate had an important adjustive function to the forming and accumulation of carbohydrate, it can rich the physiological basis of spring maize and provide theory basis and technical adjustive points for higher yield and excellent quality of spring maize. The main experiment results are as follows.The content of sucrose and the SPS activity in the leaf located near the ear fell gradually after spinning, and increased with the nitrogen application rate in certain range, while decreased caused by excessive nitrogen application rate. The SS (synthesis) activity in the leaf located near the ear appeared with single peak curve, which came to the highest value in the 28th day after spinning, all tested varieties showed peak value at the level of N200, the lowest was N0. The content of sucrose in grains increased firstly after spinning, then fell gradually, the peak value occurred in the 14th day after spinning, only FENGHE10 showed peak value at the level of N300 in the 21st day after spinning. The SS (synthesis) activity in gains appeared with single peak curve, which came to the highest value in the 21st day after spinning, all tested varieties showed peak value at the level of N200, the lowest was N0. And SIDAN19 was the highest under the condition of urea 0kg/hm2, 100kg/hm2, 200kg/hm2. The SPS activity in grains appeared with single peak curve, the peak value occurred in the 14th day after spinning, all tested varieties showed peak value at the level of N200, the lowest was N0.The contents of fructose and total soluble sugars in the leaf located near the ear was the highest in the seventh day after spinning, then fell gradually. Fructose content of SIDAN19 and FENGHENG10 showed peak value at the level of N200. The content of total soluble sugars was N200>N100>N300>N0 (except FENGHE10 in the 42th day after spinning). The contents of fructose and total soluble sugars in gains fell gradually, and the effect of nitrogen application rate on the contents of fructose and total soluble sugars in accordance to different varieties and periods.The contents of total starch, amylopectin and amylose went up in spring maize grains after spinning. The content of total starch showed peak value at the level of N200 in all tested varieties,...