生态环境学报2016，Vol.25Issue(7)：1202-1210,9.DOI:10.16258/j.cnki.1674-5906.2016.07.016
镉对斜生栅藻诱导型反牧食防御群体形成的抑制作用
Inhibitory Effect of Cadmium on the Inducible Anti-grazer Colony Formation inScenedesmus obliquus
摘要
Abstract
Cadmium contamination in aquatic ecosystems has raised concerns due to its high cytotoxicity to organisms. The inducible anti-grazer defenses in phytoplankton are known to stabilize the population dynamics and the community structures in aquatic environment. However, how the inducible defenses of phytoplankton respond to Cd contamination remains unclear.In the present study,we inoculated the algaScenedesmus obliquusinto media with or withoutDaphnia filtrate, and cultured them at different concentrations of Cd2+(0~0.32 mg·L-1). The results showed that addition ofDaphnia filtrate had no significant effect on the algal growth rate, the maximum quantum yield (Fv/Fm) and the efficiency of photosystem II (φPSI). In the presence ofDaphnia filtrate, Cd2+-free populations ofS. obliquus were comprised of 42.7% four-celled colonies on day 2 and 46.4% eight-celled colonies on day 3, with the maximum number of cells per particle of (3.3±0.20). At Cd2+ concentrations of 0.10~0.32 mg·L-1, the algal growth and photosynthesis were decreased with the result of reduced proportions of colonial populations. Exposure to≤0.08 mg·L-1 Cd2+ had no significant effect on algal growth and photosynthesis; however, the ability ofS. obliquusto form large colonies in response to Daphnia filtrate was impaired. These results suggested the high sensitivity of grazer-induced morphological defense of phytoplankton to Cd2+ toxicity. Cd contamination may result in inducible defended algae being easily grazed by small herbivorous zooplankton, potentially changing the energy flow along food chain in Cd-contaminated waters.关键词
镉/斜生栅藻/反牧食防御/群体形成/大型溞Key words
Cadmium/Scenedesmus obliquus/anti-grazer defense/colony formation/Daphnia magna分类
资源环境引用本文复制引用
黄园,南海红,张星星,汤恒星..镉对斜生栅藻诱导型反牧食防御群体形成的抑制作用[J].生态环境学报,2016,25(7):1202-1210,9.基金项目
国家自然科学基金项目（31500373）；江苏省科技厅自然科学基金项目（BK20150972）；江苏省高校自然科学研究面上项目 （）
