作 者：
徐涵;李加琦;薛素燕;陈琼琳;李阳;蒋增杰;毛玉泽;方建光
关键词：
脆江蓠;高盐胁迫;光合特性;叶绿素荧光参数;藻类夹苗
摘 要：
脆江蓠(Gracilaria chouae)藻体脆性大,短时间高盐海水浸泡可使其软化,有利于规模夹苗生产.采用实验生态学方法研究短期高盐胁迫对脆江蓠光合生理及生化组成的影响,以探讨高盐对其光合系统的损伤及其恢复效果.实验设置5个盐度梯度(40、45、50、55、60),自然海水作为对照(盐度33),分析盐度处理1h内脆江蓠的失水率及藻体软化程度;同时研究了高盐处理0.5 h及不同恢复时间(12 h、24 h)对脆江蓠pH补偿点、光合作用荧光特性、光合作用产氧量(RO)和光合色素组成等光合生理生化指标的影响.结果表明,脆江蓠在盐度50~55的海水中浸泡0.5h效果较好,此时藻体软化,并且经过24h恢复后,藻体光合作用参数可恢复到对照组水平,该处理条件可以用于脆江蓠生产.高盐(盐度40~60)处理脆江蓠0.5h,随盐度增加,脆江蓠RO值呈波动下降(P<0.01)、pH补偿点和光合效率Y(Ⅱ)值逐渐降低(P<0.05).PE含量随盐度增加而增加(P<0.01);恢复24 h后最大光合效率F_v/F_m和Y(Ⅱ)值基本恢复正常水平(P>0.05), Chl a、Car、PE和PC含量均恢复到与对照组无显著性差异水平(P>0.05).本研究旨在为提高脆江蓠规模化养殖夹苗效率提供理论依据.
作 者：
XU Han;LI Jiaqi;XUE Suyan;CHEN Qionglin;LI Yang;JIANG Zengjie;MAO Yuze;FANG Jianguang;College of Fishers and Life Sciences, Shanghai Ocean University;Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs;Shandong Provincial Key Laboratory of Fishery Resources and Eco-environment;Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences;Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology;
单 位：
XU Han%LI Jiaqi%XUE Suyan%CHEN Qionglin%LI Yang%JIANG Zengjie%MAO Yuze%FANG Jianguang%College of Fishers and Life Sciences, Shanghai Ocean University%Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs%Shandong Provincial Key Laboratory of Fishery Resources and Eco-environment%Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences%Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology
关键词：
Gracilaria chouae;;high-salinity stress;;photosynthetic characteristics;;chlorophyll fluorescence parameters;;seedling
摘 要：
To verify the feasibility of the high-salinity seawater pretreatment method and to ascertain the optimum conditions for production, the effect of high-salinity stress on the photosynthesis of Gracilaria chouae was studied using methods from experimental ecology. In this study, branches of G. chouae were incubated at five high salinity levels(40, 45, 50, 55, and 60 psu) for 30 min, with natural seawater(33 psu) as a control. Afterwards, these incubated branches of algae were transferred to natural seawater to recover for 12 h and 24 h, respectively. pH compensation point, chlorophyll fluorescence parameters, oxygenic photosynthesis, and the contents of photosynthetic pigments were measured at different salinity levels and recovery times. After algae were incubated at 40 psu for 30 min, the pH compensation point increased slightly, while RO and F_v/F_m decreased significantly. When salinity was higher than 40 psu, the pH compensation point and Y(Ⅱ) decreased, while RO decreased with increasing salinity level above 40 psu. The Chl a/Car value was significantly different among the different salinity treatment levels(P<0.01), while no significant difference was found between different incubation times within the same level of salinity. Significant changes in PE content(P<0.01) were observed, especially at 45 and 55 psu. After 12 h recovery, the overall F_v/F_m value of stressed algae was still significantly lower than of control algae(P<0.05), however,the value of Y(Ⅱ) began to increase. After 24 h recovery, the photosynthetic indices of stressed algae including F_v/F_m, Y(Ⅱ), Chl a, Car, PE, PC, and Chl a/Car were close to fully recovered. This study indicated that the algae can adjust its photosynthetic characteristics under high-salinity stress, and as a result its photosynthetic parameters are able to return to a normal level after 24 h recovery. In conclusion, the pretreatment method is feasible, and exposure to salinity of 50-55 psu for 30 minutes is a suitable treatment condition.
