| 摘要: |
| 【目的】 研究华南地区2种主要水生入侵植物凤眼莲(Eichhornia crassipes)和大薸(Pistia stratiotes)的光合特性及差异性, 探讨凤眼莲与大薸对环境光强、CO2浓度的响应机制。【方法】 于2009-08采用LI-6400便携式光合仪，测定凤眼莲与大薸的光合作用日进程、光合-光强响应曲线及光合 CO2浓度响应曲线，并进行差异性分析。【结果】 (1) 自然光照条件下,凤眼莲与大薸在1 d中的净光合速率变化均呈现“双峰”型,但凤眼莲平均净光合速率显著高于大薸；凤眼莲蒸腾速率、气孔导度的日变化较大薸更为明显。 (2) 凤眼莲的光饱和点(LSP)、光补偿点(LCP)、CO2饱和点(CSP)分别为1 520 μmol/（m2·s），31.19 μmol/（m2·s）及1 323 μmol/mol,均高于大薸,CO2补偿点(CCP为52.51 μmol/mol,低于大薸。(3) 凤眼莲与大薸的表观量子效率(AQY)分别为0.054，0.046,表观羧化效率(CE)分别为0.094，0.037,差异均达到极显著水平。【结论】 较高的光能利用力与较强的光合响应机制，是凤眼莲比大薸具有更强入侵力的生理基础。 |
| 关键词: 水生入侵植物 光合特性 净光合速率 饱和点 补偿点 |
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| 基金项目:广东省教育厅育苗工程项目（ZD906）;广东省自然科学基金项目（2007009850） |
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| Comparison of photosynthetic characteristics between two hydrophytic invasive plants |
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| Abstract: |
| 【Objective】 Some reference could be provided for the evaluation of invasive plants in Southern China Region through determining photosynthetic characteristics of Eichhornia crassipes and Pistia stratiotes.【Method】 Photosynthesis response curves and diurnal courses of P.stratiotesand E.crassipes were determined using a field photosynthesis measurement system (LI-6400).【Result】 (1) Net photosynthetic rates (Pn) of P.stratiotes and E.crassipesboth displayed “double peak” pattern in a day,but the average Pn of E.crassipes was significantly higher than that of P.stratiotes.(2) Light saturation point (LSP),light compensation point (LCP) and CO2 saturation point (CSP) of E.crassipes were 1 520 μmol/（m2·s）,31.19 μmol/（m2·s） and 1 323 μmol/mol respectively,which were much higher than that of P.stratiotes.In addition,CO2 compensation point (CCP) ofE.crassipes was 52.51 μmol/mol,which was about 19.16% lower than that of P.stratiotes.(3) Apparent quantum yield (AQY) of E.crassipes and P.stratiotes was 0.054 and 0.046,carboxylation efficiency (CE) 0.094 and 0.037,respectively,both AQY and CE reached significant levels between P.stratiotes and E.crassipes.【Conclusion】 E.crassipes has some photosynthetic advantages,such as a higher utilization rate of solar energy and a stronger mechanism of photosynthetic response etc,which is E.crassipesimportant physiological basis of stronger invasiveness than P.stratiotes. |
| Key words: hydrophytic invasive plant photosynthetic characteristic net photosynthetic rate saturation point compensation point |
