骆驼刺叶片形态和叶绿素荧光特性对不同潜水埋深的响应

摘要

本研究以策勒绿洲一过渡带自然生境中不同潜水埋深(2.5、4.5、ii.0 m)骆驼刺(Alhagi sparsifolia)为研究对象,分析了自然生境中骆驼刺叶片形态、叶绿素含量和叶绿素荧光特征对不同潜水埋深的响应.结果表明,潜水埋深由2.5m增加到4.5 m时,骆驼刺的叶面积、比叶面积和叶绿素b含量分别增加22％、15％和14％,叶片厚度减小18％,差异均达到显著水平(P＜0.05);当潜水埋深由4.5m增加到11.0 m时,叶面积、叶片厚度、叶绿素a含量、叶绿素b含量和叶绿素(a+b)含量分别增加14％、15％、17％、32％和21％,最大荧光Fm、PSⅡ潜在活性Fv/F.和PSⅡ最大光化学效率Fv/Fm分别升高14％、24％和9％,比叶面积减小12％,差异均达到显著水平(P＜0.05).研究结果可为策勒绿洲—过渡带中自然生长的骆驼刺的保护及生态恢复提供科学依据.%Here we report our study of the responses of leaf morphology,pigment content,and chlorophyll fluorescence in A.sparsifolia shrubs growing in soils where the groundwater table is found at 2.5,4.5 or 11.0 m deep into the soil profile,in a natural arid environment in northwest China.The results showed that at 4.5 m groundwater table depth,leaf area,specific leaf area,and chlorophyll (Chl) b were 22％,15％ and 14％ greater than at 2.5 m groundwater table depth,respectively;whereas,leaf thickness was 18％ thinner.Additionally,leaf area,leaf thickness,Chl a,Chl b,Chl (a+b),maximum fluorescence yield (Fm),potential activity of PSⅡ (Fv/Fo),and maximum photochemical efficiency of PSⅡ (Fv/Fm) at 11.0 m groundwater table depth were greater by 14％,15％,17％,32％,21％,14％,24％ and 9％,respectively,relative to 4.5 m depth to the groundwater table;whereas,specific leaf area was 12％ smaller.This research provides a sound theoretical basis to better protect and restore A.sparsifolia in the Cele oasis-desert transitional zone in northwest China.