水分胁迫下华北地区主要造林树种离体枝条叶片的叶绿素荧光参数

Response of Fluorescence Parameters in Detached Leaves of Several Tree Species in HuaBei District to Drought Stress

通过分析离体叶片保水力大小、荧光参数随胁迫程度加深的变化及荧光参数与水分参数的相关性,探讨了毛白杨、华山松等华北地区主要造林树种离体枝叶叶绿素荧光参数随不同干旱胁迫程度的变化,主要结论如下:(1)针叶树种保水力普遍较阔叶树种强,各树种保水机制具有较大差异;(2)失水时间对荧光参数的变化具有显著影响,失水过程中,5种针叶树种荧光参数Fv/Fm、Fm/Fo与失水率均呈明显的线性关系,不同的是,参数Fv/Fm的变化曲线呈“凸”状,Fm/Fo的变化曲线呈倒“S”状;(3)不同胁迫程度时,树种荧光参数与水分参数的相关性具有明显差异,程度愈深,相关性愈显著;(4)荧光参数能对树种抗旱性给予定性的描述,但作为定量度量指标则表现出一定的局限性。

By analyzing the water-holding capacity of detached leaves, change of fluorescence parameters with the extent of water stress and the relationship between fluorescence parameters and water parameters, the response of fluorescence parameters in detached leaves of several tree species in Huabei district to drought stress was discussed. Four main conclusions were drawn as follows ： （ 1 ） coniferous trees generally had stronger water-holding capacity than broadleaf trees, their waterholding mechanism, however, were quite different;（2） orescence parameters, and during the course of water trees had obvious linear relationship with water-losing ） the length of water-losing time essentially affected the change of flustress, fluorescence parameters Fv/Fm and Fm/Fo of five coniferous rate, the difference lied in that the variation curve of parameter Fv/ Fm presented a protruding design and parameter Fm/Fo presented a eurve of inverted ＂S＂ ; （3）under different stress extent, the relationship between fluorescence parameters and water parameters showed significant difference, the higher the water stress was, the more significant the correlationship was; （4）fluorescence parameters could give a qualitative description for drought-resistant quality of tree, but as a quantitative index, they showed some extent of limitations.