模拟淹水对池杉和栓皮栎光合生理生态过程的影响  

The effects of waterlogging on photosynthesis-related eco-physiological processes in the seedlings of Quercus variabilis and Taxodium ascendens

作　　者：衣英华[1] 樊大勇[1] 谢宗强[1] 陈芳清[2] 

机构地区：[1]中国科学院植物研究所植被与环境变化重点实验室,北京100093 [2]三峡大学生态环境中心,湖北宜昌443002

出　　处：《生态学报》2008年第12期6025-6033,共9页Acta Ecologica Sinica

基　　金：中国科学院西部行动计划资助项目(KZCX2-XB2-07);国家科技支撑计划课题资助项目(2006BAC10B01)~~

摘　　要：池杉(Taxodium ascendens)和栓皮栎(Quercus variabilis)是我国亚热带河岸带和库塘消落区常见的植物,对于河岸带和库塘消落区的水土保持和水源涵养具有十分重要的作用。研究通过测定二者的最大净光合速率、光饱和曲线、二氧化碳饱和曲线、根/茎/叶的可溶性糖含量、叶片的比叶重(leafmass perunitarea,LMA)和根系活力等指标研究了模拟淹水(50d)对两年生栓皮栎和池杉树苗生理生态过程的影响。在淹水过程中,栓皮栎的最大净光合速率不断下降,到试验结束时淹水处理的最大净光合速率降低为对照的9%,而且处理与对照差异极显著;而在整个淹水过程中池杉则在处理和对照间没有显著差异。淹水胁迫下:(1)淹水导致栓皮栎表观量子效率(φ)不断下降,淹水第6天降为对照的59.9%左右(P<0.001),第26天降为对照的40.9%左右(P<0.001),而26d的淹水对池杉的光饱和曲线却影响不大;(2)淹水导致栓皮栎羧化效率(CE)的不断下降,在正常生长条件下栓皮栎的CE为(0.331±0.075)μmolm-2s-1Pa-1。淹水第10天栓皮栎的CE下降到对照的22.1%,淹水第30天降到对照的16.8%,且差异均显著(P<0.001)。淹水对池杉的二氧化碳饱和曲线没有造成显著影响;(3)淹水导致两个种的根/茎/叶可溶性糖含量呈现动态变化。50d的淹水导致栓皮栎叶片可溶性糖含量相比于对照略有上升,茎和根可溶性糖含量显著上升。而池杉根/茎/叶可溶性糖含量对照和处理之间差异不显著;(4)淹水导致栓皮栎的比叶重持续升高,池杉的与对照没有显著差异;(5)淹水导致栓皮栎的根系活力持续下降,池杉则开始时下降后又升高,这可能与池杉在淹水过程中产生了有利于吸收氧气的不定根,而栓皮栎没有产生不定根有关。以上实验结果说明相对池杉,栓皮栎应属于对淹水较敏感的树种。短期淹水(1～10d)导致栓皮栎光合速率下降的生理生态原因应该至少包括表�Taxodium ascendens and Quercus variabilis （Cork Oak） are very important species distributed in the subtropical riverside and drawdown area of reservoirs and ponds in China. In this study, to investigate the effects of waterlogging on the eco-physiological processes of these two species, the maximum net photosynthesis rate, apparent quantum yield （φ）, apparent carboxylation efficiency（ CE）, content of soluble sugar of root/stem/leaf, Leaf Mass per unit Area （LMA） as well as the root activity of these two species under waterlogging conditions were measured. Waterlogging caused a persistent decrease of maximum photosynthetic rate of Cork Oak （ on the 50th day of waterlogging, the value was only 9 % of control）. In contrast, there was no significant difference of maximum photosynthetic rate between waterlogged and control seedlings of Taxodium ascendens. It was shown that： （ 1 ） the φ of Cork Oak was decreased by waterlogging （6 days of waterlogging decreased φ to 59. 9% of control, 26 days of waterlogging decreased φ to 40. 9% ）, while waterlogging caused no significant change of φ of Taxodium ascendens; （2） under normal conditions, the CE of Cork Oak was approximately （0. 331±0. 075）μmol m^-2s^-1Pa^-1, waterlogging induced a persistent decrease of CE （10 days of waterlogging decreased CE to 22. 1% of control, 30 days decreased to 16.8% ）, while waterlogging caused no significant changes in the CE of Taxodium ascendens ; （3） the soluble sugar content of the root/stem/leaf of both species also showed kinetic responses under waterlogging stress. At the beginning of waterlogging （10th day）, the soluble sugar content of the leaf and root of Cork Oak was less than the control ; afterwards, it was higher than the control. Comparably, the soluble sugar content of stem of Cork Oak was higher than control during the period of treatment. As for Taxodium ascendens, the soluble sugar content of root/ stem/leaf was not significantly different between waterlogging and contr

关 键 词：池杉 栓皮栎 模拟淹水 生理生态过程 

分 类 号：Q945[生物学—植物学]