大气CO_2浓度升高对大型海藻孔石莼生长和色素含量的影响

Effects of elevated atmospheric CO_2 concentration on growth and pigment contents of macroalga Ulva pertusa

在实验室模拟研究了大气CO2浓度升高对海洋中大型绿藻孔石莼Ulva pertusa的生长和色素含量的影响。设置4个独立试验,每个试验的CO2浓度分别为387、500、600、800 mg/L。每个试验设6个海水培养系统,其中3个通入一定浓度的CO2作为试验系统,另外3个通入大气作为对照系统。在每个海水培养系统中,分别装入25 L过滤海水(滤膜孔径为0.22μm),放入(50.0±1.0)g的孔石莼进行培养,试验进行7 d。结果表明:高浓度CO2对孔石莼生长无显著影响(P>0.05),但降低了孔石莼中叶绿素a和类胡萝卜素的含量;试验结束时,CO2浓度为387、500、600、800 mg/L时,试验系统中孔石莼的叶绿素a含量分别为(855.9±31.6)、(780.8±6.2)、(677.3±22.1)、(585.1±16.9)μg/g(鲜质量),分别为对照系统的98.3%、91.8%、78.4%和71.7%,试验系统中孔石莼的类胡萝卜素含量分别为(185.6±5.0)、(167.8±2.4)、(150.6±2.3)、(128.3±4.3)μg/g(鲜质量),分别为对照系统的97.7%、91.5%、80.4%和69.4%;而对照系统中试验开始时和试验结束时,孔石莼的叶绿素a含量和类胡萝卜素含量均无显著性差异(P>0.05)。

Effects of rising atmospheric CO2 levels on growth and pigment contents was studied in macroalga Ulva pertusa in a laboratory.The macroalga was cultivated at a biomass of （50.0±0.1）g per tank in six 25 L sands-filtered （0.22 μm） seawater culture systems （SCS） subjected to aeration with CO2 at a rate of 387,500,600 and 800 mg/L （as test system） and subjected to aeration with air（as control system） for 7 days.The results showed that there were no significant effects of rising atmospheric CO2 levels on growth of the macroalga（P〉0.05）.However,the chlorophyll a （Chl.a） and carotenoid levels were found to be decreased,with Chl.a content of （855.9 ±31.6）,（780.8±6.2）,（677.3±22.1）,and （585.1±16.9） μg/g（fresh weight） at atmospheric CO2 concentration of 387,500,600 and 800 mg/L at the end of the experiment,respectively,and representing 98.3%,91.8%,78.4% and 71.7% in the control group,respectively.The average contents of carotenoid were found （185.6±5.0） μg/g（fresh weight） at the atmospheric CO2 concentration of 387 mg/L,（167.8±2.4） μg/g（fresh weight） at the atmospheric CO2 concentration of 500 mg/L,（150.6±2.3）μg/g（fresh weight） at the atmospheric CO2 concentration of 600 mg/L,and （128.3 ±4.3） μg/g（fresh weight） at the atmospheric CO2 concentration of 800mg/L,accounting for 97.7%,91.5%,80.4% and 69.4% in the control groups,respectively.Nevertheless,there were no significant differences in contents of carotenoid and Chl.a in both the control system and the test system at the beginning and the end of the experiment （P〉0.05）.