Effect of Different Nitrogen Treatments on Stomatal Density and Other Physiological Characters in Rice Leaves

With four rice varieties,Fengjin, Liaojing5, IR36 and Shuiyuan287 as materidls, stomatal density and other physiological characters of flag leaf were studied under two nitrogen fertilizer treatments. The results indicated that the stomatal density of all the varieties descended under high-N treatment, and all were lower than those under low-N treatment. These suggested that the reason of this phenomena had a close relationship with the significant increase of leaf area of flag leaves. Comparative with low-N treatment, the chlorophyll concentrations and net photosynthetic rates of flag leaves under high-N treatment were higher, but the transpiration rates and stomatal conductances were lower. The stomatal densities had positive correlations with transpiration rates and stomatal conductance, but had negative correlations with net photosynthetic rates of flag leaves.