| 摘要: |
| 【目的】了解不同质量浓度SO2对红花檵木光合速率及叶绿素荧光参数的影响，为园林植物的栽培与利用提供理论依据。【方法】采用人工模拟熏气法，以0（对照），2.86，5.71和14.28 mg/m3 4个SO2质量浓度对红花檵木进行密闭熏气3 d，1周后利用LI-6400光合仪和PAM 2500便携式荧光仪分别测定叶片光合参数及叶绿素荧光参数，研究SO2胁迫对红花檵木光合特性的影响。【结果】随着SO2质量浓度的增加，红花檵木叶片净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）下降，胞间CO2浓度（Ci）上升；初始荧光(Fo)增加，其中14.28 mg/m3 SO2处理比对照显著增加23.71%；最大荧光产量(Fm)、PSⅡ的最大光化学效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)降低，其中14.28 mg/m3 SO2处理下Fv/Fo较对照下降51.75%。不同SO2质量浓度下各叶绿素荧光参数的光响应结果表明，随着光强的增加，PSⅡ实际光合量子产量Y(Ⅱ)、光化学淬灭系数qP下降，非光化学淬灭系数qN、PSⅡ光合电子传递速率ETR上升。【结论】5.71 和14.28 mg/m3 SO2处理会引发红花檵木PSⅡ反应中心比例降低，光合电子传递受阻，PSⅡ色素吸收的光能用于光化学电子传递的份额减少，光能转化效率和潜在活性降低，进而影响植株的正常光合作用。 |
| 关键词: SO2胁迫 红花檵木 光合速率 叶绿素荧光 |
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| 基金项目:四川省农作物育种攻关项目(2011NZ0098-10) |
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| Effects of SO2 stress on photosynthetic rate and chlorophyll fluorescence parameters of Loropetalum chinense var.rubrum |
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HOU Liqin,ZHOU Lanying,PU Guanglan,et al
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| Abstract: |
| 【Objective】This study investigated the effects of SO2 stress on photosynthetic rate and chlorophyll fluorescence parameters in leaves of Loropetalum chinense var.rubrum to improve its cultivation and utilization.【Method】The influence of SO2 on L.chinense var.rubrum was studied by fumigation for 3 d in this experiment.There were four SO2 treatments with concentrations of 0(CK),2.86,5.71,14.28 mg/m3,respectively.After one week,LI-6400 photosynthesis system and PAM-2500 portable X-ray fluorescence spectrometer were used to measure leaf photosynthetic parameters and chlorophyll fluorescence parameters of L.chinense var.rubrum.【Result】With the increase of SO2 concentration,net photosynthetic rate (Pn),stomatal conductance (Gs) and transpiration rate (Tr) decreased,while intercellular CO2(Ci) increased.Concentration of dark fluorescence yield (Fo) also increased and its highest concentration increased significantly by 23.71% compared to CK.Maximum fluorescence yield (Fm),maximum PSⅡ quantum yield (Fv/Fm),and latent PSⅡ quantum yield (Fv/Fo) decreased.The Fv/Fo in treatment of 14.28 mg/m3 SO2 decreased by 51.75% compared with CK.With the increase of photosynthetic active radiation,PSⅡ actual photosynthetic quantum yield Y(Ⅱ) and coefficient of photochemical quenching (qP) decreased and coefficient of non photochemical quenching (qN) and electron transport rate (ETR) increased.【Conclusion】The SO2 treatments with concentrations of 5.71 and 14.28 mg/m3 decreased PSⅡ reaction center ratio of L.chinense var.rubrum,blocked photosynthetic electron transport,decreased the rate of photochemistry electron transfer to total absorbed energy by PSⅡ pigment,and reduced energy conversion efficiency and potential activity,which affected normal photosynthesis. |
| Key words: sulfur dioxide stress Loropetalum chinense var.rubrum photosynthetic rate chlorophyll fluorescence parameters |
