盐胁迫对塔胞藻生长及叶绿素荧光动力学的影响

Effects of Salt Stress on the Growth and Chlorophyll Fluorescence of Pyramidomonas sp.

利用调制式叶绿素荧光仪（Water-PAM）研究了盐度（1～120）胁迫不同时间（12，24，48h）后，塔胞藻生长及叶绿素荧光动力学的变化。测定的主要参数有：PSⅡ的最大光能转化效率（Fv／Fw）、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）。结果表明：在本实验条件下，塔胞藻生长和进行光合作用的最适盐度为20。高盐胁迫使塔胞藻的荧光参数Fv／Fm，Fv／Fo，φPsⅡ，ETR，qP均明显降低，NPQ则先升高后降低，叶绿素含量和细胞密度也显著降低。还对盐胁迫下塔胞藻的响应机制以及叶绿素荧光技术在筛选耐盐微藻品种中的应用进行了初步探讨。

The modulate chlorophyll fluorescence kinetics of Pyramidomonas sp. exposed to different salinities （1-120） for different time periods （12h, 24h and 48h） were investigated with a Water-PAM chlorophyll fluorometer. The main parameters determined in the present study include the maximal photochemical efficiency of PS Ⅱ （Fv/Fm）, the potential activity of PS Ⅱ （Fv/Fo）, the actual photochemical efficiency of PS Ⅱ in the light （φPS Ⅱ = yield）, the electron transport rate （ETR）, the photochemical quenching （qP） and the nonphotochemical quenching （NPQ）. The results showed that the optimal salinity for the growth and photosynthesis of Pyramidomonas sp. was 20 under the experimental conditions. The fluorescence parameters Fv/Fm Fv/Fo, φPSⅡ, ETR and qP decreased while NPQ significantly increased then decreased under high salt stress. The cell density and chlorophyll content of Pyramidomonas sp. also decreased under high salt stress. The responsive mechanism of Pyramidomonas sp. to salt stress as well as the possibility of determining the salt resistance in microalgae using chlorophyll fluorescence induction kinetics was also discussed in this paper.