中文摘要：

采用叶绿素荧光技术分析盐胁迫对蛋白核小球藻光系统I（PSI）和光系统II（PSII）的影响及其机理. 小球藻在BG11培养基中培养，培养基中NaCl的浓度梯度为0、0.2、0.4、0.6、0.8、1 mol/L，在处理72 h后测定其叶绿素荧光参数. 试验发现，蛋白核小球藻PSII最大潜在量子产量（Fv/Fo）、质体琨库（Fv/2）、潜在光化学效率（Fv/Fo）随盐浓度的升高呈下降趋势，NaCl的浓度为1 mol/L时，其分别降低了43.9%、70.5%和70.3%；PSII 有效量子产量（Y（II））、PSII光化学淬灭（qP）随着有效辐射强度（PAR）的升高而逐渐降低，并在400 μmol m-2 s-1以后趋于稳定；而电子传递速率（ETR（II），ETR（I））、非光化学淬灭（qN和NPQ）随着有效辐射强度（PAR）的升高先升高后逐渐降低，最后趋于稳定. 综上表明，盐胁迫下蛋白核小球藻PSII的电子传递速率和光化学量子效率降低，PSII复合体受到破坏，最终导致其光化学效率降低；PSI由于受到盐胁迫，其光化学反应速率降低；本研究结果对进一步研究盐胁迫对藻类光合作用的影响机制具有重要意义.

英文摘要：

Salt stress is a common phenomenon in the environment but its effects on photosystems Ⅱ （PSⅡ） and Ⅰ （PSⅠ） of algae are still not well understood. This study aimed to elucidate the effects of salt stress on the electron transport chain from PSII to PSI. Chlorella pyrenoidosa was cultivated in BG11 medium. NaCl concentration in the medium was set as 0, 0.2, 0.4, 0.6, 0.8 and 1 mol/L. Seventy two hours after salt stress, PSII and PSI activities were synchronously monitored using the DUAL-PAM 100 chlorophyll fluorometer. The results showed that salt stress reduced the potential PSII photochemical efficiency （Fv/Fo）, plastoquinone storeroom （Fv/2） and PSII maximal photochemical efficiency （Fv/Fm）. The actual photochemical efficiency of PSII （Y（Ⅱ）） and photochemical quench （qP） of the C. pyrenoidosa tended to decrease as the photosynthetically active radiation （PAR） increased. With increasing PAR, electronic transfer rate （ETR（II）, ETR（I）） and non-photochemistry quench （qN, NPQ） of the C. pyrenoidosa first increased to the maximum and then decreased to a stable value. The results indicated that salt stress may impair the PSII complexes of C. pyrenoidosa, reduce its electronic transfer efficiency and photochemical quantum efficiency, and decrease PSI photochemical reaction rate.