冬小麦叶片氮素时空分布特征及其与籽粒品质的关系

The Properties of Temporal and Spatial Distributions of Leaf Nitrogen and the Relationship between Leaf Nitrogen and Grain Quality in Winter Wheat

从时间变化、水平和垂直空间分布的角度对冬小麦氮素营养指标进行了分析。结果表明 ,株型紧凑的普通籽粒蛋白品种“京冬 8(JD8)”叶片全氮含量于返青后 16d达最大值 ,而株型松散的籽粒高蛋白型品种“中优 95 0 7(95 0 7)”于返青后 8d达最大值。后期 95 0 7叶片全氮含量下降明显 ,JD8则不同。两品种叶片叶绿素 (Chl)含量随时间消长的总趋势基本一致 ,但与叶片全氮含量变化趋势存在差别。不同类型品种对施氮量的反应不同 ,95 0 7不同施氮量间叶片全氮和Chl含量差异较小 ,而同样变化幅度的施氮量则引起JD8叶片全氮和Chl含量的明显变化。两者叶片全氮、叶绿素含量、LAI垂直分布趋势大致相同 ,但JD8各测定时期叶片全氮指数 (TNI)、叶绿素指数 (CI)及LAI层次差异明显 ,95 0 7层次梯度小于JD8。拔节期两品种TNI、CI及LAI均随层次降低而递减 ;开花期的规律性较为复杂 ;灌浆期两品种TNI都以第 2层最高 ,2、3、4层间呈递减趋势 ,CI的规律不同于TNI。两品种叶片“氮素垂直梯度”及“氮素输出量”均存在明显差异 ,冠层不同层次叶片对籽粒品质的贡献不同。

Under field condition, the properties of temporal and spatial distributions of leaf nitrogen content for winter wheat were analyzed. The results showed that there appeared difference in temporal and spatial distributions between the two observed winter wheat cultivar. The maximum value of leaf total nitrogen content of the two cultivar appeared at different growth stage, 'Jingdong 8(JD8)', a common grain protein content cultivar, appeared at 16 days after reviving, but 'Zhongyou 9507(9507)', a higher grain protein cultivar at 8 days after reviving. At late growth stages, the leaf nitrogen content of '9507' decreased quicker than that of 'JD8'. There was a similar trend of leaf chlorophyll(Chl) content in both cultivars but a different trend of changes between Chl content and leaf total nitrogen content. There was less discrepancy of leaf nitrogen and Chl contents between different amount nitrogen applications in '9507', but obvious changes of that in 'JD8'.The vertical distribution of leaf total nitrogen index(TNI), leaf Chl index(CI) and LAI were differed in the two cultivars. There were apparent differences of TNI, CI and LAI in different layers of 'JD8'. But '9507' showed less layer gradients of TNI, CI and LAI than those of'JD8'. At jointing, the TNI and CI of both 'JD8' and '9507' decreased gradually with the layer descended. There were more complex rules of TNI, CI and LAI changes for the two cultivars in different layers at anthesis. At grain filling, the second layer of both the two cultivars had the highest TNI. There showed different trends of CI and TNI in different layers.There existed distinct differences of leaf nitrogen vertical gradient and nitrogen output amount between the two cultivars. The leaves in different layers had different contribution to winter wheat grain quality.