高效液相色谱和原位荧光法比较研究威氏海链藻光合色素组成

采用高效液相色谱(HPLC)和活体荧光方法研究了威氏海链藻(Thalassiosira weissflogii)在不同营养状态下其色素比值的变化．结果显示氮(N)限制相对磷(P)限制对威氏海链藻生长有更大的抑制作用．HPLC的结果显示在氮限制条件下，细胞的墨角藻黄素(Fucoxanthin)／叶绿素a、叶绿素c／叶绿素a比值高于磷限制和未受营养盐限制条件(对照组)；活体荧光结果则显示氮限制条件下550nm／440nm，460nm／440nm激发荧光比值低于磷限制和对照组．这两种方法来指示浮游植物的生理状态以及研究其类群结构存在一定差异，综合比较和评价这两种方法在指示浮游植物生理状态及类群结构中各自的优越性，结果表明活体荧光能明显地指示威氏海链藻细胞生长状态的变化，比较适宜用于指示不同生理状态下威氏海链藻的光合色素比值变化，而用HPLC来研究营养限制条件下威氏海链藻细胞的生长变化以及计算其类群的组成较为合适．

Comparative Study on Pigment Composition of Thalassiosira Weissflogii Using HPLC and In - vivo Fluorescence

The variation of pigment ratios of Thalassiosira Weissflogii under different nutrients conditions was determined by both HPLC and in - vivo Fluorescence methods. The results showed that N limitation was comparatively more important for the growth of Thalassiosira Weissflogii. The HPLC results showed that under N limited condition, the Fucoxanthon/Chlorophyll a and Chlorophyll c/ Chlorophyll a ratios were higher than those under P - limited and unlimited conditions; on the contrary in - vivo Fluorescence results showed that the Fluorescence intensity ratios under 550nm/440nm, 460 nm/440 nm excitation lights were lower than those of P - limited and unlimited groups. The evaluation of phytoplankton community structure using these two methods might raise great difference. A comprehensive comparison about the advantages of these two methods in indicating phytoplankton and community structure showed that in - vivo Fluorescence could clearly indicate the variation of growth phase of Thalassiosira Weissflogii and was more suitable to indicate the variation of pigment ratios of Thalassiosira Weissflogii among different physiological status. On the contrary, the comparison result showed that HPLC was more appropriate to study the growth changing of Thalassiosira Weissflogii under nutrients limited conditions and to calculate the phytoplankton community structure.