首先采用藻类荧光产率模型,以荧光饱和参数Eσ作为饱和激发光强的判断标准,提出了一种激发光强自适应方法,以准确获取不同藻类的光合荧光参数。结果表明,7种藻经自适应调整后可快速而稳定地获得饱和激发光强,调整结果的相对标准偏差均小于2.5%。然后利用激发光强自适应的可变光脉冲诱导荧光(TPLIF)技术测量了7种藻的有效光吸收截面σPSII,并分析了不同门类藻的σPSII差异。最后采用TPLIF技术测量了不同生长时期的小球藻样品,记录了其荧光参数Fv/Fm值和变化趋势,并将其与光合活性分析仪Fast-Ocean的测量结果进行对比,结果发现两者测得的Fv/Fm值保持一致,相关系数为0.9939。本研究为不同生长时期(生长状态差异明显)、不同种类藻光合荧光参数的准确测量提供了有效的饱和激发手段。

Based on the model of algae fluorescence yield and with the fluorescence saturation parameter E_σ as the judgment standard of saturated excitation light intensity, we proposed a self-adaptive method of excitation light intensity to accurately acquire the photosynthetic fluorescence parameters of different species of algae. The results show that with the self-adaptive method, the saturated excitation light intensity could be quickly and stably obtained in the seven species of algae, and the relative standard deviations (RSDs) of the adjustment results were all smaller than 2.5%. Furthermore, the effective light absorption cross-sections σ_PSII of the seven species of algae were measured by the tunable pulse laser induced fluorescence (TPLIF) technique based on the self-adaptive method, and the difference in the σ_PSII of different species of algae was analyzed. Finally, we measured the Chlorella samples at different growth stages through the TPLIF technique and recorded their fluorescence parameter F_v/F_m and relevant variation trend. It turns out that the recorded results are consistent with the measurement results of the photosynthetic activity analyzer Fast-Ocean, with the correlation coefficient being 0.9939. In conclusion, this study provides an effective way of saturation excitation for accurately measuring the photosynthetic fluorescence parameters of different species of algae at different growth stages (with obvious differences in growth status).