Comparison of the photo-acclimation potential of fl oating and benthic thalli of Sargassum horneri(Phaeophyta)during autumn and winter  

作　　者：Jingjing LI Yunlong PANG Song QIN Zhengyi LIU Zhihai ZHONG Wanlin SONG Longchuan ZHUANG 

机构地区：[1]Key Laboratory of Marine Hazards Forecasting,Ministry of Natural Resources,Hohai University,Nanjing 210098,China [2]Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai 264003,China [3]Weihai Vocational College,Weihai 264200,China [4]Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,China

出　　处：《Journal of Oceanology and Limnology》2022年第1期195-205,共11页海洋湖沼学报（英文）

基　　金：Supported by the National Key Research and Development Program of China(No.2016YFC1402106);the National Natural Science Foundation of China(Nos.31700327,42006110);the Natural Science Foundation of Shandong Province(No.ZR2019QD017);the Fundamental Research Funds for the Central Universities(No.B200202140);the Key R&D Projects in Shandong Province(International Scientifi c and Technical Cooperation)(No.2019GHZ026)。

摘　　要：Sargassum horneri is a foundational species and an important contributor to the fl oating seaweed stock along the northeastern coast of Asia.In this study,benthic and fl oating thalli of S.horneri were collected from Changdao Island(37°54′N,120°43′E),Bohai Bay,China.We conducted an in-situ and an indoor experiment to study the acclimation potential in S.horneri to abiotic conditions at sea surface in autumn and winter.Both benthic and fl oating thalli were cultured in situ for two months(from October to December)at diff erent depths:0 m above sea level(masl)and 3 m below sea level(mbsl),and their growth rate,biochemical content,and photosynthetic performance were compared.During the fi rst month of culture,the relative growth rate of fl oating thalli was 2-fold greater than that of benthic thalli at 0 masl.The photosynthetic rate of most thalli was signifi cantly higher at 0 masl than at 3 mbsl.In the indoor experiments,fl oating and benthic thalli were exposed to high light intensity(400μmol photons/(m^(2)·s)photosynthetically active radiation(PAR))for 21 d,and their photo-acclimation capacities were compared.Under high light intensity,the two types of thalli showed low maximum quantum yield(F_(v)/F_(m))and light utilisation effi ciency(α)but high light saturation point(E_(k)).Floating thalli showed higher photosynthetic rate and photoprotective ability than benthic thalli at high light intensity.The eff ective quantum yield of photosystem II[Y(II)]of both types of thalli recovered after a 6-day treatment with low light intensity(40μmol photons/(m^(2)·s)).These fi ndings suggest that S.horneri is highly acclimated to the sea surface environment,which possibly contributes to its rapid accumulation and long free-fl oating periods at the sea surface.

关 键 词：chlorophyll-a fl uorescence growth photosynthesis photosynthetic pigments Sargassum horneri 

分 类 号：Q948[生物学—植物学]