在海洋酸化背景下温度变化对大型绿藻缘管浒苔光合生理特性的影响  

The responses of photosynthetic physiology in macroalga Ulva linza to temperature variation under ocean acidification

作　　者：刘雅萌[1,2] 汤镇铭 李信书[1] 杨梓[1] 姚东瑞[3] 刘兆普[2] 徐军田[1] 

机构地区：[1]淮海工学院江苏省海洋资源开发研究院,江苏连云港222005 [2]南京农业大学资源与环境科学学院,南京210095 [3]江苏省中国科学院植物研究所植物景观与生态工程研究中心,南京210014

出　　处：《生态学杂志》2014年第9期2402-2407,共6页Chinese Journal of Ecology

基　　金：江苏省自然科学基金项目(BK2011400);国家海洋局海洋公益性行业科研专项(201205010);江苏省"青蓝工程"人才基金项目资助

摘　　要：为了探讨在未来海洋酸化背景下温度变化对大型海藻的影响,选取了绿潮藻缘管浒苔(Ulva linza)作为实验材料。实验设置2个CO2浓度,分别为正常空气水平(LC:390μL·L-1)和高CO2水平(HC:1000μL·L-1),在20℃下从缘管浒苔的幼苗开始培养,等成体后转入不同的温度梯度(5、10、15、20、25和30℃)下测定藻体的光合作用。结果表明:海洋酸化显著提高了缘管浒苔的相对生长速率,虽然藻体光合作用速率没有明显变化,但藻体的呼吸作用和硝酸还原酶能力显著增加;对于光合色素来说,高CO2显著降低了叶绿素a和叶绿素b的含量;温度变化在不同CO2处理下表现为不同的效应;长期生长在20℃的缘管浒苔,当环境温度降低时,其最大光合作用速率Pmax、呼吸作用Rd、光饱和点Ik和光补偿点Ic都随之降低,而光合效率α则是先升高再降低,其中高CO2提高了藻体的α、Rd和Ic;而当温度增加时,缘管浒苔的Pmax和Ik都随之升高,α、Rd和Ic都有下降的趋势,高温下高CO2的α和Rd较高,光补偿点较低。相较于正常环境来说,海洋酸化下的缘管浒苔对温度的骤变具有更好的适应能力。In this ture on macroalgae study, the green alga Ulva linza was selected to assess the effects of temperaunder the ocean acidification condition. The juvenile U. linza was cultured at two CO2 concentrations [ normal, 390 μL·L-1（LC） ; elevated, 1000μL·L-1 （HC） ] and at 20 ℃, then the response of photosynthetic physiology of adult algae to temperature changes （5, 10, 15, 20, 25 and 30 ℃ ） was measured. Our results showed that high CO2 significantly enhanced the relative growth rate of U. linza, with the enhancements of the nitrate reductase activity and respiration rate （Rd）, although the net photosynthetic rates were not significantly changed. Moreover, the contents of Chl a and Chl b significantly decreased when the algae was cultured at the high CO2 level. An instantaneous change in temperature resulted in different photosynthetic performance at the different CO2 concentrations. When the temperature decreased, the maximum photosynthetic rate （ Pmax ） , respiration rate （Ra）, light saturation point （ Ik ） and light sation point （Ic） were reduced. However, photosynthetic efficiency （a） increased first compen- and then decreased with the increase of temperature. High CO2 concentration significantly enhanced α, Rd and Ic compared to the control treatment. Pmax and Ik were enhanced with the temperature in- crease, while α, Rd and Ic showed an opposite trend. Moreover, α and Rd at high temperature were higher in HC-grown algae than in LC-grown algae, but Ic was lower in HC-grown algae. Compared to the LC-grown algae, the HC-grown algae had a better ability to adapt high temperature.

关 键 词：缘管浒苔 海洋酸化 温度 生长 光合作用 

分 类 号：S917.3[农业科学—水产科学]