高温胁迫对三角褐指藻和纤细角毛藻叶绿素荧光动力学的影响

Effects of High Temperature Stress on the Chlorophyll Fluorescence Kinetics ofPhaeodactylum tricornutum and Chaetoceros gracilis

研究高温胁迫（35～50℃）对三角褐指藻和纤细角毛藻叶绿素荧光动力学的影响。利用调制式叶绿素荧光仪（Water-PAM）测定了：PSⅡ的最大光能转化效率（Fv／Fm）；PSⅡ的潜在活性（Fv／Fo）；PSⅡ的实际光能转化效率（φPSⅡ=yield）；光合电子传递效率（ETR）；光化学淬灭（qP）和非光化学淬灭（NPQ）等主要参数。结果表明，与对照组相比，高温胁迫下2种硅藻的叶绿素荧光参数Fv／Fm，Fv／Fo，φPS Ⅱ，ETR和qP均明显降低，并且随着胁迫温度的升高，胁迫时间的延长，下降幅度也逐步增大；NPQ则先升高后下降。另外，还对高温胁迫下2种硅藻的响应机制以及叶绿素荧光技术在筛选耐高温微藻品系中的应用进行了初步探讨。

The modulate chlorophyll fluorescence kinetics of Phaeodactylum tricornutum and Chaetoceros gracilis under high temperature stress （35- 5012 ） were investigated with Water-PAM chlorophyll fluorometer. The main parameters determinedin the present study include maximal photochemical efficiency of PS Ⅱ （ Fv/Fm ）, potential activity of PS H （ Fv/Fo ）, actual photochemical efficiency of PS H in the light （φPS Ⅱ = yield）, electron transport rate （ETR）, photochemical quenching （qP） and non-photochemical quenching （NPQ）. The results showed that the parameters Fv/Fm, Fv/Fo, φPS Ⅱ, ETR and qP decreased while NPQ first increased then decreased under high temperature stress. The change degree of the above parameters increased with the increase of temperature and the increasing exposure time in the two diatoms. The responsive mechanism of the two diatoms to high temperature stress as well as the possibility of determining the high temperature resistance in microalgae using chlorophyll fluorescence induction kinetics is also discussed in this paper.