研究了甲藻和硅藻两个门类的六种浮游植物在发射波长为675 nm处的活体叶绿素荧光激发光谱。对其作四阶导数分析的基础上,根据导数光谱中出现的极大值位置和数量,对甲藻门和硅藻门的激发光谱分别设定统一的初始中心波长。以初始波长为中心对激发光谱做高斯分解及多峰拟合,建立门类水平上统一的高斯基库。研究发现,在波长为350～550 nm内,甲藻和硅藻的高斯基库特征差异显著,而同门类的高斯基库特征相似,表明高斯分解法为甲藻和硅藻的分类识别提供有效的技术手段。利用高斯基库的参数拟合原光谱,拟合曲线与原光谱能较好地吻合,误差小。高斯分解法可再现活体激发光谱中重叠的色素荧光峰,也为光合色素的活体测定提供了新的方法。

In vivo chlorophyll fluorescence excitation spectra at 675 nm emission wavelength of six phytoplankton species belonging to dinophyta and bacillariophyta were studied. The fourth-derivative analysis was performed on the spectra to set up the uniform initial central wavelengths for excitation spectra of dinophyta and bacillariophyta, respectively, according to the position and number of maxima on the derivative spectra. With these determined wavelengths as centre, Gaussian decomposition and multi-peak fitting were done to the spectra to establish Gaussian database on the level of divisions. The results suggested that at the excitation wavelength from 350 to 550 nm, significant differences of Gaussian database presented between dinophyta and bacillariophyta while similar characteristics were found in the same division. The fitting curve reconstructed from Gaussian parameters was in coincident with the in vivo excitation spectra. Gaussian decomposition could reproduce overlapping pigment fluorescence peaks. This method provides not only a useful tool to differentiate dinophyta and bacillariophyta, but also a new technique for determination of in vivo photosynthetic pigments.