施氮对半湿润农田冬小麦冠层叶片氮素含量和叶绿素相对值垂直分布的影响  

Effect of Nitrogen on Nitrogen Vertical Distribution and Chlorophyll Relative Value of Winter Wheat Canopy in Sub-humid Areas

作　　者：党蕊娟[1] 李世清[1] 穆晓慧[1] 李生秀[1] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨陵712100

出　　处：《西北植物学报》2008年第5期1036-1042,共7页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(30571116,30670326)

摘　　要：选用半湿润地区土垫旱耕人为土和冬小麦品种‘小偃22’,通过田间试验研究了在不同施氮水平下冬小麦不同生育期冠层叶片含氮量、叶绿素相对值的垂直分布规律,并分析了它们与小麦穗粒重的相关性。结果表明,小麦各生育期冠层叶片含氮量从上至下呈明显递减规律,并且均随施氮量增加含氮量逐渐提高,倒一叶平均比倒二叶高15.83%,倒二叶平均比倒三叶高25.79%;随着施氮量增加,各叶位间叶片含氮量梯度差在拔节期和孕穗期相对稳定,而倒二叶与倒三叶含氮量梯度在成熟期逐渐加大。冠层叶片叶绿素相对值的垂直分布规律与含氮量相似,倒一叶平均比倒二叶高6.5%,倒二叶平均比倒三叶高27.43%。叶片叶绿素相对值与其含氮量呈极显著正相关(r=0.744**,n=234),其间的一元饱和回归方程为ySPAD=87.90xN/(2.29+xN)(R2=0.710);各叶位叶绿素相对值、叶片含氮量均与其穗粒重大多呈显著正相关,并以倒一叶的相关性最密切。研究发现,施氮能提高小麦冠层叶片的含氮量和叶绿素相对值以及它们在叶片间的梯度差,但不能改变它们自上而下逐渐递减的垂直分布规律。A field experiment was carried out in sub-humid areas using Eum orthic authrosols and winter wheat varieties ＇Xiaoyan 22 ＇. It studied the vertical distribution patterns of canopy leaf nitrogen content and leaf chlorophyll relative value, the differences of different layer leaves under different nitrogen levels of winter wheat in different growth stages and the correlation analysis among them and wheat yield per sui. The results showed that the different growth stages of leaf nitrogen content were significantly reduced by top-down rule,and the nitrogen content in different layers increased as the nitrogen increased in the treatments. As the level of the N fertilizer increased, the gradient at different layer leaf nitrogen content was relatively stable,but the gradient between L2 and L3 layer increased in mature stage. The law of canopy leaf chlorophyll content was similar with the vertical distribution of leaf nitrogen content, L1 was 6.5 % higher than L2 in average,and L2 was 27.43% higher than L3. Correlation analysis indicated that the linear correlation between chlorophyll relative value and leaf nitrogen content was very significant （r= 0. 744^＊＊ , n= 234）, and the regression equation was YSPAD = 87. 90xN / （2. 29 ＋xN ） （R^2 = 0.710）. It was mostly significant- ly positive correction among SPAD value, N content and grain yield per single-ear, and L1 was the most closely related. The research found that nitrogen fertilizer could increase leaf nitrogen content and leaf chlorophyll relative value and the gradient at different layer leaf, but it could not change the top-down rule of the vertical distribution.

关 键 词：冬小麦 叶片含氮量 叶绿素相对值 垂直分布 

分 类 号：Q945.79[生物学—植物学]