荧光动力学法藻类初级生产力测量中光合尺寸单元校正方法研究

Correction Method of Photosynthetic Size Unit in Algae Primary-Productivity Measurement using Fluorescence Kinetics

荧光法作为一种非侵入性测量手段,能够实现水体藻类初级生产力的快速测量。然而在目前初级生产力荧光动力学分析中,藻类光合尺寸单元通常采用固定值,导致初级生产力测量结果发生偏差,特别是水体存在蓝藻时尤为明显。光合尺寸单元定义为光合反应中心浓度与叶绿素浓度的比值。为获得准确的水体藻类光合尺寸单元以提高初级生产力测量结果的准确性,利用激发荧光光谱分析水体蓝藻和其他真核藻占比,以此为基础对混合藻样品光合尺寸单元进行校正,并提出一种基于光合尺寸单元校正的荧光法藻类初级生产力测量方法。纯种样品和混合样品初级生产力比对测试实验结果表明:纯种蓝藻、绿藻、甲藻样品的初级生产力测量误差由校正前的38.8%、14.3%、13.2%下降至3.9%、4.1%、5.2%;混合样品初级生产力最大和平均测量误差由校正前的20.4%、15.2%下降至4.5%、5.2%。该结果证明,所提校正方法可有效解决光合尺寸单元使用固定值带来的初级生产力测量偏差问题,为提高水体藻类初级生产力测量结果的准确性提供了重要参考。

The fluorescence method is a noninvasive measurement method that can rapidly measure the primary productivity of algae in aquatic systems.However,in the current analysis of fluorescence dynamics of primary productivity,when the photosynthetic size unit of algae is used with a fixed value,the measurement results of the primary productivity of algae in an aquatic system often exhibit deviations,particularly where cyanobacteria existing.The photosynthetic size unit is defined as the ratio of the photosynthetic reaction center concentration to the chlorophyll concentration.Herein,to obtain accurate algae photosynthetic size units and improve the accuracy of the primary productivity,excitation fluorescence spectroscopy was employed to analyze the proportion of cyanobacteria and other eukaryotic algae.As a result,the photosynthetic size unit of the mixed algae sample was corrected,and a fluorescence method based on the photosynthetic size unit correction is proposed to measure the primary productivity of algae.The results of a comparison test of the primary productivity of purebred and mixed samples demonstrate that using the proposed correction method,the measurement errors of the primary production of purebred cyanobacteria,chlorophyta,and pyrrophyta samples are reduced from 38.8%,14.3%,and 13.2%to 3.9%,4.1%,and 5.2%,respectively.In addition,the maximum and average measurement errors of the primary productivity of the mixed sample decrease from 20.4%and 15.2%to 4.5%and 5.2%,respectively,compared with those without correction.The proposed method can effectively resolve the measurement result deviation problem caused by the fixed value of the photosynthetic size unit.The proposed method provides an important reference to improve the measurement accuracy of primary productivity of algae in aquatic systems.