纺锤形苹果树冠层不同区位叶片光合有效辐射积累与叶片质量关系的研究

Spatial distribution of dry leaf weight per area, leaf nitrogen and nonstructural carbohydrate concentration in relation to local radiation regime within a tall spindle apple tree crown

【目的】为探究纺锤树形苹果树冠层不同区位太阳辐射积累与叶片质量关系,【方法】以盛果期纺锤树形苹果树为试材,采用实时动态光合有效辐射测量技术,测定了冠层内不同区位光辐射累积,并测定该区位叶片比叶重、氮含量、非结构碳水化合物含量等指标。【结果】苹果树冠垂直方向不同层次光合有效辐射日均积累量从上到下逐步下降,水平方向光合有效辐射日均积累量从内膛到外围逐步增大;树冠内叶片质量参数和部分叶片内碳水化合物含量从上到下逐步下降,树冠水平方向叶片质量参数和部分叶片内碳水化合物含量从内膛到外围逐步增大。日均光合有效辐射积累量同叶片质量参数和叶片葡萄糖山梨醇淀粉呈显著正相关,与蔗糖和果糖含量没有显著相关性,建立了日均光合有效辐射积累量同叶片单位面积N含量的线性回归方程N a=0.863+0.0668DPAR。【结论】纺锤树形冠层从高到低,从外围到内膛叶片质量参数和碳水化合物含量呈减小趋势,日均光合有效辐射积累量可作为推断叶片单位面积含氮量的指标。

[Objective]Research was aimed to find out the spatial distribution of leaf dry weight per unit area, leaf nitrogen concentration and total leaf nonstructural carbohydrate concentration in relation to local mean daily PAR （Photosynthetic active radiation） within a tall spindle apple tree crown within a tall spindie apple tree crown. [Method]A tall spindle Fuji apple tree used as material. The distribution of relevant leaf mean daily PAR intercepted（DPAR） was measured, leaf dry weight per area （Wa concentration （Nw and Na） were investigated, nonstructural carbohydrate concentration and leaf nitrogen sucrose, glucose, fructose, sorbitol, starch） in leaves were investigated by high performance liquid chromatography method （HPLC）. [Results]Within the crown, DPAR gradually increased from bottom to top and gradually increased from inner to outer. High spatial heterogeneity was observed for Wa, Nw, Na, sucrose, glucose, sorbitol, starch, and they gradually increased from bottom to top and inner to outer. Wa, Nw, Na, glucose, sorbitol, starch were strongly correlated to DPAR. Sucrose and fructose were not correlated to DPAR. From this experiment, useful linear regression equation between Na and DPAR for leaf physiological model （Na= 0.863 0.0668DPAR） were derived. [Conclusion]Leaf quality characteristics gradually increased from bottom to top and gradually increased from inner to outer. DPAR can be used as the index of Na.