Growth And Nitrogen Utilization Of Early Rice Under Different Water Levels

In this paper, Xiangzhaoxian6, Z liangyou68, Xiangliangyou68and Zhuliangyou819as material, were studied by using of isotope tracer techniques and conventional technology. The agronomic traits, photosynthetic physiology, leaf physiology and nitrogen utilization of early rice under different water levels (semiarid, water saving treatment, shallow and deep water) were measured. The results are as follows:1, Water-saving treatment will increase yield of early rice. Under water saving treatment, shallow and deep water, the flag leaf length, ear length, grains per spike and1000-grains weight of early rice have no significant difference, but they did not under semiarid; while the maximum tiller number, seed setting rate, yield per plant, effective tiller number and maturity have significant difference under different water levels and were significantly better under water-saving treatment than under other three treatments.2, Suitable water helps to improve leaf photosynthetic efficiency of rice. The difference of net photosynthetic rate, leaf transpiration rate, intercellular CO2concentration, stomatal conductance and chlorophyll of four early rice varieties under different water levels were significant, and show same trend in every early rice varieties:the indexes under semiarid were the lowest, under water saving treatment was maximum and then slowly decreased with increasing water.3, Effects of water on content of peroxidase, catalase activity and proline, soluble sugar in rice is very obvious. Semiarid and deep-water rice were two abiotic stresses of rice, increased contents and activity of proline, peroxidase and catalase, and decreased contents of soluble sugar content. In all water levels, Effects of shallow water and water saving treatment is minimal on content of peroxidase, catalase activity and proline, soluble sugar in rice.4, Proper water was beneficial to nitrogen absorption and utilization of rice. In tillering stage, heading stage, filling stage and ripe stage, the15N contents in leaf of early rice were investigated, and the results of15N showed that:the water levels of semiarid and deep water went against of absorption and utilization of nitrogen in rice, but the water saving treatment and shallow water were not.