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高等植物PSII最大光化学量子产量的测定   

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Original research article

A brief version of this protocol appeared in:
Rice Protocol e-book

实验原理:植物叶片经过暗处理之后,可以通过PAM荧光仪激发出红色的荧光,再反馈到荧光仪,从而可以获得在PSII不同开放程度下的Fo、Fm等基本荧光参数。
实验目的:通过PAM荧光仪测量高等植物光系统II的最大光化学量子产量Fv/Fm,以揭示植株是否处于正常健康的生理状态。

关键词: 叶绿素荧光参数, Fv/Fm, 胁迫

材料与试剂

  1. 50 ml离心管
  2. Triton X-100或琼脂糖

仪器设备

  1. PAM-2500调制式叶绿素荧光仪 (Walz公司生产)
  2. 暗适应叶夹(DLC-8,Walz公司生产)

实验步骤

本实验方案视频见视频1。

视频1. Measurement of Fv/Fm

  1. 取样时将叶片放入含有0.01% Triton X-100或者0.1%琼脂糖溶液的50 ml离心管中,带回实验室放入暗室进行暗处理,暗处理的时间最少2 h,暗室内的光强PPFD要小于10 μmol m−2 s−1
  2. 暗处理完成后,将叶片从离心管中取出擦干后用暗适应叶夹夹住。
  3. 先将PAM-2500荧光仪连接电源,再与UMPC连接,最后连接上光纤。连接完成后开启UMPC和PAM-2500,打开软件PAMwin-3,进入PAM-2500的野外测量屏幕。
  4. 将暗适应叶夹与光纤连接,拉开暗适应叶夹,点击Field screen界面的Fv/Fm,荧光仪发出饱和脉冲,从而获得Fv/Fm的值,即PSII最大光化学量子产量。

结果与分析

高等植物在没有受到胁迫、正常的生理状态下,Fv/Fm的值在0.80-0.84之间。但是当叶片受到胁迫之后该值会显著下降。

注意事项

  1. PAM-2500荧光仪与UMPC、电源连接时一定要连接正确,否则仪器会出现严重故障。
  2. 禁止过度弯曲光纤,且光纤末端不要对着眼睛,以免发生灼伤。
  3. 在野外测量时,电池的电压低于9.4 V时PAM-2500应当立即关闭 (图1)。
  4. 打开暗适应叶夹,在饱和脉冲激发前,实时荧光值Ft应当在300-900之间,如果不在这个范围,应当调节Gain值,使其达到这个范围再进行测量。


    图1. PAM-2500的野外测量屏幕

    注:基本荧光参数说明(图1):
    F0, F0’: Minimal fluorescence level excited by very low intensity of Measuring Light to keep PSII reaction centers open from dark- or light-adapted leaf, respectively.
    Fm, Fm’: Maximal fluorescence level elicited by a strong light pulse which close all PSII reaction centers from dark- or light-adapted leaf, respectively.
    Fv, Fv’: Variable fluorescence from dark- or light-adapted leaf, respectively. Fv = Fm - F0, Fv’ = Fm’ - F0’ .
    Ft, F: The Ft denotes the continuously recorded fluorescence. The value of Ft measured shortly before a Saturation Pulse with light exposed samples is denoted “F”.
    Fv/Fm = (Fm-F0)/Fm: Maximum photochemical quantum yield of PSII.

Copyright: © 2018 The Authors; exclusive licensee Bio-protocol LLC.
引用格式:付湘逵, 刘畅, 李星磊, 王功伟. (2018). 高等植物PSII最大光化学量子产量的测定. Bio-101: e1010168. DOI: 10.21769/BioProtoc.1010168.
How to cite: Fu, X. K., Liu, C., Li, X. L. and Wang, G. W. (2018). Determination of the Maximum Quantum Yield of PS II Photochemistry in Higher Plants. Bio-101: e1010168. DOI: 10.21769/BioProtoc.1010168.
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