Allelopathic eff ects of mixotrophic dinofl agellate Akashiwo sanguinea on co-occurring phytoplankton:the signifi cance of nutritional ecology  

作　　者：Yeyin YANG Bozhu HUANG Yingzhong TANG Ning XU 

机构地区：[1]Department of Ecology/Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes,Jinan University,Guangzhou 510632,China [2]Guangdong Environmental Monitoring Center,Guangzhou 510308,China [3]Key Laboratory of Marine Ecology and Environmental Sciences,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China

出　　处：《Journal of Oceanology and Limnology》2021年第3期903-917,共15页海洋湖沼学报（英文）

基　　金：Supported by the National Natural Science Foundation of China(NSFC)(Nos.41576159,41676099)。

摘　　要：Blooms of Akashiwo sanguinea frequently break out around the world,causing huge economic losses to the aquaculture industry and seriously damaging coastal ecosystems.However,the formation mechanisms of A.sanguinea blooms remain unclear.We investigated the allelopathic effects of A.sanguinea on multiple phytoplankton species,explored the mode of allelochemicals action and the way of nutrient factors regulation of the allelopathic activity.Results show that strains of A.sanguinea could inhibit the growth of co-occurring phytoplankton including Scrippsiella trochoidea,Phaeocystis globosa,and Rhodomonas salina,but inhibition of Prorocentrum micans was not obvious.The inhibition rates on phytoplankton were positively correlated with the cell densities of A.sanguinea.The highest inhibition rate of 94%on R.salina was for A.sanguinea CCMA256 culture of 2000 cells/mL at 72 h.We observed that cells of S.trochoidea,Ph.g lobosa,and R.sali na were lysed when co-cultured with A.sanguinea,with the shortest time for S.trochoidea.Additionally,the growth rates of A.sanguinea were promoted by coculturing with S.trochoidea,Ph.globosa,and R.salina.Four components of A.sanguinea culture were all able to inhibit growth of R.salina:the strongest inhibitory effect was found in the sonicated culture,followed by whole-cell culture,filtrates of sonicated culture,and filtrate culture.The crude extract of A.sanguinea culture also lysed cells of R.salina,and the inhibition rates on R.salina increased with the increasing dose of crude extract.It was shown that both nutrient enrichment and nitrogen:phosphorus ratio imbalance enhanced remarkably the allelopathic activity of A.sanguinea.The highest inhibition rate on R.salina of 70%occurred in A.sanguinea JX13 treatment at 2000 cells/mL under high nutrient condition in 48 h.In JX14 treatment at 2000 cells/mL for N:P of 10:1,the inhibition rate increased by 1.7 times of that for N:P of 20:1.In addition,the allelopathy of A.sanguinea could not only be a competitive strategy but also a nutrition stra

关 键 词：Akashiwo sanguinea harmful algal blooms MIXOTROPHY ALLELOPATHY nutrients 

分 类 号：Q948.8[生物学—植物学]