大气CO_2增加对不同生长光强下龙须菜光合生理特性的影响  

Effects of elevated CO_2 concentration on the photosynthetic physiological characteristics of Gracilaria lemaneiformis grown under different light levels

作　　者：郑伟[1] 钟志海[2] 杨梓[1] 刘雅萌[1] 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,连云港222005 [2]汕头大学海洋生物研究所,汕头515063

出　　处：《生态学报》2014年第24期7293-7299,共7页Acta Ecologica Sinica

基　　金：国家自然科学基金(41476097;41106093);江苏省高校自然科学基金(12KJB17002);江苏省"青蓝工程"人才基金;江苏高校优势学科建设工程资助项目

摘　　要：为了探讨未来大气CO2升高对不同生长光强下大型海藻的影响,选取经济红藻龙须菜为实验材料,研究了其生长速率、光合作用、呼吸作用、叶绿素荧光参数以及光合色素对CO2和光强的响应。实验设置两个CO2浓度,正常空气水平CO2浓度(390μL/L)和高CO2浓度(1000μL/L);两个光强梯度,高光(300μmol m-2s-1)和低光(100μmol m-2s-1)。结果表明,CO2和光强对龙须菜的生长和光合作用有明显的交互作用。大气CO2升高并没有显著影响龙须菜的生长速率,但在不同CO2处理下,龙须菜对光强的响应不同。在空气水平下,光强的变化对其生长速率影响不显著。而在高CO2作用下,高光处理下的藻体有更高的生长速率。CO2显著促进高光生长下龙须菜的呼吸作用速率,但是在低光下作用不明显。而对于光合作用速率来说,低光培养下的藻体CO2表现为负面效应,但对高光下生长的藻体作用不明显。CO2增加没有改变龙须菜生长状态下的电子传递速率,但在高光下,CO2表现为一定的抑制作用。CO2显著降低了龙须菜天线色素藻红蛋白和叶绿素a的含量。这些CO2与光强的结合效应表明,大气CO2的升高对龙须菜光合生理特性的影响随着光强的变化而呈现不同的效应,在未来评估CO2的增加对大型海藻的影响时,要充分考虑其他环境因子的耦合效应。To obtain the adaptive capacity of macroalgae to light-change environment in future elevated CO2 condition,we selected the economic red macroalga Gracilaria lemaneiformis as the experimental material to study the co-effects of light and CO2 on the growth rate,respiration rate,net photosynthetic rate,chlorophyll fluorescence parameters and the contents of photosynthetic pigments. Two CO2 levels and two light intensities were set in this study. The different CO2 concentrations treatments were set as（ 1） actual atmospheric CO2concentration： average of the p CO2 was about 390 μL / L; and（ 2） High CO2level： p CO2 concentration was about 1000 μL / L. Target p CO2 in this study was achieved by bubbling pre-mixed air-CO2 mixtures from the plant growth CO2 chamber,which controls the CO2 level with a variation of less than 3%. The different light levels were attained with cool white fluorescent tubes（ 300 μmol m-2s-1,HL; and 100μmol m-2s-1,LL）. The culture medium was renewed every two days using filtrated seawater and about 64 and 8 μmol / L concentrations of nitrateand phosphate were added,respectively. The culturing densities of G. lemaneiformis were controlled exactly to maintain the p H in the medium changed less than 0.05. Our results showed that the significant interactions of CO2 and light were found in the photosynthetic performance and relative growth rate of G. lemaneiformis. elevated CO2 concentration had no significant effect on the relative growth rate of G. lemaneiformis,but light played different roles when the thalli was cultured in different CO2 levels. In atmospherical CO2 condition,no difference was found between high and low light treatments; while the higher growth rate was found in the high light treatment when the thalli was cultured under high CO2 level. CO2 stimulated the respiration rate of G. lemaneiformis cultured under high light level,but no effect was found in that under low light condition.For net photosynthetic rate,CO2 showed the negative effects when the thalli grown

关 键 词：龙须菜 CO2 光强 生长 光合作用 

分 类 号：S644.6[农业科学—蔬菜学]