Growth and photosynthesis responses of Phaeodactylum tricornutum to dissolved organic matter from salt marsh plant and sediment  

作　　者：Yihua Xiao Qinghui Huang Ling Chen Penghui Li 

机构地区：[1]Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China [2]State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China

出　　处：《Journal of Environmental Sciences》2010年第8期1239-1245,共7页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 40601095);the Sino-Russia International Cooperation Program (No.2007DFR90050);the State Key Laboratory of Pollution Control and Resources Reuse (No. PCRRY003)

摘　　要：The effects of allochthonous dissolved organic matter （DOM） on the growth and photosynthesis of Phaeodactylum tricornutum were investigated. P. tricornutum incubated in f/2 medium was exposed to DOM additives, which were extracted from the plant and sediment samples of a salt marsh in North Branch of the Yangtze estuary, China. During 12 days incubation, the chlorophyll fluorescence parameters of P. tricornutum were measured by a Phyto-PAM phytoplankton analyzer. Spectral properties of DOM in algae filtrates were also observed. The concentrations of chlorophyll a, active chlorophyll a, and the maximum quantum yield of photosystem II significantly decreased after four days of incubation, suggesting that the growth and photosynthetic efficiency of P. tricornutum were inhibited. After adding sediment-DOM extract, both a 250 /a 365 （the ratio of the absorption coefficients at 250 and 365 nm） and S values （spectral slope coefficients） of algae filtrates declined in the first two days, which demonstrated a loss of low molecular weight DOM. Parallel factor analysis of fluorescence spectra of DOM in algae filtrates revealed that DOM could be classified into two humic-like and two protein-like components. The fluorescence intensity of tyrosine-like component originating from algae increased significantly during incubation. This study supports the hypothesis that allochthonous DOM derived from salt marsh plant and sediment have a strong influence on the adjacent aquatic ecosystems.The effects of allochthonous dissolved organic matter （DOM） on the growth and photosynthesis of Phaeodactylum tricornutum were investigated. P. tricornutum incubated in f/2 medium was exposed to DOM additives, which were extracted from the plant and sediment samples of a salt marsh in North Branch of the Yangtze estuary, China. During 12 days incubation, the chlorophyll fluorescence parameters of P. tricornutum were measured by a Phyto-PAM phytoplankton analyzer. Spectral properties of DOM in algae filtrates were also observed. The concentrations of chlorophyll a, active chlorophyll a, and the maximum quantum yield of photosystem II significantly decreased after four days of incubation, suggesting that the growth and photosynthetic efficiency of P. tricornutum were inhibited. After adding sediment-DOM extract, both a 250 /a 365 （the ratio of the absorption coefficients at 250 and 365 nm） and S values （spectral slope coefficients） of algae filtrates declined in the first two days, which demonstrated a loss of low molecular weight DOM. Parallel factor analysis of fluorescence spectra of DOM in algae filtrates revealed that DOM could be classified into two humic-like and two protein-like components. The fluorescence intensity of tyrosine-like component originating from algae increased significantly during incubation. This study supports the hypothesis that allochthonous DOM derived from salt marsh plant and sediment have a strong influence on the adjacent aquatic ecosystems.

关 键 词：PHYTOPLANKTON chlorophyll a FLUORESCENCE parallel factor analysis 

分 类 号：Q949.2[生物学—植物学] X131[环境科学与工程—环境科学]