以蛋白核小球藻为受试对象,以藻类光合荧光参数为毒性评价指标,研究Cu 2+毒性作用下多个光合荧光参数的响应规律。结果显示:Cu 2+对光合荧光参数F0、Fm、Fv、Fv/Fm、Yield、rP、JVPⅡ、α和Ek抑制效应显著,其中Yield、rP、α和Fv/Fm在24 h内体现出稳定的抑制效应,可作为24 h分析Cu 2+毒性的评价指标;Yield、rP、α和Fv/Fm抑制程度对Cu 2+浓度具有良好的剂量效应关系,logistic函数拟合相关系数R2分别为0.9989,0.9992,0.9991,0.9977,由此得到EC50-24h值分别为61.05,66.31,69.41,99.61 μmol·L -1。因此,参数Yield、rP、α的拟合相关系数优于常规参数Fv/Fm,其对应的EC50-24h分别降低了38.7%,33.45%,30.3%。研究结论可为基于藻类光合抑制效应的生物毒性测试指标选择提供参考。

Herein, Chlorella pyrenoidosa was taken as the subject, and photosynthetic fluorescence parameters of algae were used as toxicity evaluation indexes to study the response law of multiple photosynthetic fluorescence parameters under Cu ²⁺ toxicity. The results are as follows: the inhibition effect of F₀, Fm, Fv, Fv/Fm, Yield, rP, JVPⅡ, α and Ek on Cu ²⁺ toxicity is significant, and yield, rP, α and Fv/Fm could be used as the evaluation indexes for Cu ²⁺ toxicity analysis at 24 h; the inhibitory effect of Yield, rP, α and Fv/Fm has a good dose-effect relationship with Cu ²⁺ toxicity. The fitting correlation coefficient R² of the logistic function is 0.9989, 0.9992, 0.9991 and 0.9977, and the resulting EC_50-24h is 61.05, 66.31, 69.41 and 99.61 μmol·L ^-1, respectively. The parameters Yield, rP and α have higher fitting correlation coefficients than the conventional parameter Fv/Fm, and their EC_50-24h values decrease by 38.7%, 33.45% and 30.3%, respectively. The experimental results could provide reference for the detection of biological toxicity based on photosynthetic inhibition effect of algae.