Spring dinoflagellate blooms are always severe in the Three Gorges Reservoir(TGR),China,threatening water ecological health.Many dinoflagellates are capable of mixotrophism,yet the influence of dissolved organic matte...Spring dinoflagellate blooms are always severe in the Three Gorges Reservoir(TGR),China,threatening water ecological health.Many dinoflagellates are capable of mixotrophism,yet the influence of dissolved organic matter(DOM)on their growth and blooms in spring remains unclear.This study characterized the source and composition of DOM from sediment,soil,and plant,and assessed their effects on the growth of bloom-forming algal species(Peridiniopsis sp.and Microcystis aeruginosa)under different temperatures.The results showed that sediment and soil DOM promoted Peridiniopsis sp.growth,plant DOM slightly inhibited it.However,DOM had no significant effect on M.aeruginosa growth.The promotion of sediment and soil DOM on Peridiniopsis sp.growth was higher at 15℃and 20℃ than at 25℃.Moreover,the effect of DOM on Peridiniopsis sp.growth was more significant than that of high nitrogen and phosphorus.Fulvic acid-like,humic-like and tyrosine-like substances of DOM in sediment and soil might be the effective components promoting the Peridiniopsis sp.growth,while tryptophan-like substance of plant DOM might hinder it.Sediment and soil DOM might promote the Peridiniopsis sp.growth mainly by providing adequate organic carbon,increasing protein content,and improving photosynthesis.The findings will provide important information for the formation and control of dinoflagellate blooms in TGR.展开更多
基金supported by the National Key Research and Development Program(No.2021YFC3201003)。
文摘Spring dinoflagellate blooms are always severe in the Three Gorges Reservoir(TGR),China,threatening water ecological health.Many dinoflagellates are capable of mixotrophism,yet the influence of dissolved organic matter(DOM)on their growth and blooms in spring remains unclear.This study characterized the source and composition of DOM from sediment,soil,and plant,and assessed their effects on the growth of bloom-forming algal species(Peridiniopsis sp.and Microcystis aeruginosa)under different temperatures.The results showed that sediment and soil DOM promoted Peridiniopsis sp.growth,plant DOM slightly inhibited it.However,DOM had no significant effect on M.aeruginosa growth.The promotion of sediment and soil DOM on Peridiniopsis sp.growth was higher at 15℃and 20℃ than at 25℃.Moreover,the effect of DOM on Peridiniopsis sp.growth was more significant than that of high nitrogen and phosphorus.Fulvic acid-like,humic-like and tyrosine-like substances of DOM in sediment and soil might be the effective components promoting the Peridiniopsis sp.growth,while tryptophan-like substance of plant DOM might hinder it.Sediment and soil DOM might promote the Peridiniopsis sp.growth mainly by providing adequate organic carbon,increasing protein content,and improving photosynthesis.The findings will provide important information for the formation and control of dinoflagellate blooms in TGR.
