Effects of Different Nitrogen Levels on Grain-filling Characteristics and Yield of Two Dryland Wheat Cultivars for Superior and Inferior Grain

The effect of nitrogen level on grain filling characteristics and yield of dryland wheat cultivars for superior and inferior grains under the condition of pot culture were studied.The result indicated that did not influenced N application in creased grain number,grain weight and yield,but thousand grain weight.The filling rate of superior grains was obviously higher than that of inferior grains,and both superior and inferior grain filling rate shows the trend of increasing at first,then decreasing with the increase of nitrogen level.Correlation analysis indicated that,there existed significantly positive correlations of superior grain weight with filling rate and accumulative time.However,there were significantly positive correlations of inferior grain weight with the duration of the maximum filling rate and duration of each filling stage.