不同光谱结构对铜绿微囊藻光合活性和固碳特征的影响

EFFECTS OF DIFFERENT SPECTRAL STRUCTURES ON PHOTOSYNTHETIC ACTIVITY AND CARBON SEQUESTRATION CHARACTERISTICS OF MICROCYSTIS AERUGINOSA

为探究自然水体中不同水层的光谱结构对藻类光合活性和固碳特征的影响,以三峡库区高阳平湖0,0.5,1,3m水层的光谱结构监测结果为依据,选用优势种铜绿微囊藻为研究对象,在相同光强下,搭建A组(0m)、B组(0.5m)、C组(1m)、D组(3m)4种不同的光谱结构,以白光(E组)为对照,分析不同光谱结构对铜绿微囊藻光合活性和固碳特征的影响。其中光源由红光、黄橙光、绿光、蓝光及紫光按不同比例组合而成,由A~D组蓝紫光和绿光占比依次降低,黄橙光占比依次升高。结果表明:1)各实验组藻密度均高于对照组(E组),藻密度表现为C组>D组>B组>A组>E组。2)光合活性,A组的F_(v)/F_(m)、rETR_(max)及α较其他组高,E_(k)值较其他组低,A组的光合活性最高,耐高光的能力较差;能量分配,BC组的ABS/RC、TR_(0)/RC、ET_(0)/RC值较高,单位反应中心捕获的能量和用于电子传递的能量高;3)固碳特征,C组光反应提供的能量高,CA酶活性和固碳速率最高。表明在相同光强下,蓝紫光占比越高,藻类反应中心捕获的光能就越低,对藻类密度的促进作用也越低,固碳速率也越低,黄橙光则反之;但黄橙光占比过高,也会抑制藻类的生长,需结合2个光系统捕光复合物的吸收光能特性进行具体分析。

In order to explore the influence of spectral structure of different water layers in natural water body on photosynthetic activity and carbon fixation characteristics of algae,based on the monitoring results of spectral structure of 0,0.5,1,3 m water layers in Gaoyangping Lake of the Three Gorges Reservoir Area,Microcystis aeruginosa was selected as the research object.Under the same light intensity,four different spectral structures were built,namely,group A(0 m),group B(0.5 m),group C(1 m),and group D(3 m),with white light(group E)as the control,The effects of different spectral structures on photosynthetic activity and carbon fixation characteristics of Microcystis aeruginosa were analyzed.The light source is composed of red light,yellow orange light,green light,blue light and purple light in different proportions.The proportion of blue violet light and green light in groups A to D decreases in turn,and the proportion of yellow orange light increases in turn.The results showed that:1)the algal density of each experimental group was higher than that of the control group(Group E).The algal density of group C>group D>group B>group A>group E.2)Photosynthetic activity,F_(v)/F_(m),rETR_(max)andαCompared with other groups,E_(k)value was higher and lower.Group A had the highest photosynthetic activity and poor high light tolerance;In the results of energy distribution,the ABS/RC,TR_(0)/RC,ET_(0)/RC values of group BC were higher,and the energy captured per unit reaction center and used for electron transfer were higher;3)characterized by carbon fixation,group C has the highest energy provided by light reaction,CA enzyme activity and carbon fixation rate.It shows that under the same light intensity,the higher the proportion of blue violet light,the lower the light energy captured by the algal reaction center,the lower the promotion effect on the algal density,and the lower the carbon fixation rate,while the opposite is true for yellow Orange light;However,the high proportion of yellow orange light will also inhibit the growth of algae,so it is necessary to analyze the light absorption characteristics of the light harvesting complex of the two light systems.