Effects Of Zizanialatifolia Soaking Liquid On Microcystis Aeruginosa Of Islet Wetland Of Poyang Lake

In recent years,the water quality of Poyang Lake has been declining.There is a risk of outbreak of cyanobacteria blooms.The community of pod Zizanialatifolia has rapidly expanded,forming a single pupa community structure that is difficult to use;using the Poyang Lake Islet Wetland Zizanialatifolia soaking liquid to suppress cyanobacterial outbreaks can achieve a win-win result.To examine the impact of Zizanialatifolia soaking liquid,a dominant plant at the bottomland of Poyang Lake,on the growth of Microcystis aeruginosa.And nitrogen and phosphorus nutrition,nitrogen limitation and phosphorus limit on Zizanialatifolia soaking liquid allelopathic inhibition.Under the indoor aseptic condition with temperature and intensity control.Observed and analyzed the cell density,population morphology,cell morphology,and physical and chemical indicators of Microcystis aeruginosa.The main results of this study are as follows:(1)The first time in this study,it was reported that under the eutrophic conditions,Zizanialatifolia soaking liquid of Poyang Lake beach affected the growth of Microcystis aeruginosa,and showed a phenomenon of “low promotion and high suppression”.The growth of Microcystis aeruginosa was promoted,when the Zizanialatifolia soaking liquid was less than 3g/L.The growth of Microcystis aeruginosa was inhibited when the Zizanialatifolia soaking liquid was more than 6g/L,and the inhibition rate was 43.3%.Utilizing Zizanialatifolia soaking liquid to inhibit the growth of algae in Poyang Lake,the concentration of the Zizanialatifolia soaking liquid should be greater than 6g/L.(2)Different levels of nitrogen and phosphorus have different effects on the production of Zizanialatifolia soaking liquid allelopathic algal growth,and the growth of Microcystis aeruginosa is influenced by low and medium concentrations of nitrogen and phosphorus,showed a phenomenon of “low promotion and high suppression”.The growth of Microcystis aeruginosa was inhibited when the Zizanialatifolia soaking liquid was more than 6g/L,the inhibitory rates were 16.7% and 43.3% under low and medium concentrations of nitrogen and phosphorus nutrients,respectively.Under high nitrogen and phosphorus concentrations,the Zizanialatifolia soaking liquid also affected the growth of Microcystis aeruginosa,but no inhibitory effect was observed.Under the condition of high nitrogen and phosphorus nutrient,Poyang Lake vegetation vegetation promotes the growth and reproduction of algae in Poyang Lake.(3)Under nitrogen/phosphorus limitation,the effects of extracts on the growth of Microcystis aeruginosa showed a phenomenon of “low promotion and high suppression”..The concentration of Zizanialatifolia soaking liquid was less than <3g/L promoted the growth of Microcystis aeruginosa.The growth of M.aeruginosa was inhibited when the Zizanialatifolia soaking liquid was more than 3 g/L.The limiting inhibition rates of N/P were 38.09% and 38.1% when the Zizanialatifolia soaking liquid was 6 g/L,respectively.Phosphorus nutrients have a greater impact on the inhibition of growth of algae in Poyang Lake by the eucalyptus plantation on Poyang Lake Beach,and the discharge of phosphorus nutrients from Poyang Lake should be controlled.(4)The Zizanialatifolia soaking liquid had little effect on cell diameter,malondialdehyde,and extracellular polysaccharide content of Microcystis aeruginosa;when the Zizanialatifolia soaking liquid increased to 6g/L,Accumulation of malondialdehyde in cells of Microcystis aeruginosa,the destruction of cell membrane ion channel and the reduction of cell diameter,which will eventually inhibit the growth of Microcystis aeruginosa.There duction of the growth rate of Microcystis aeruginosa can result in the accumulation of extracellular polysaccharide(EPS),which favors the formation of Microcystis aeruginosa colony.It will help Microcystis aeruginosacells to resist allelopathy and grow.(5)Under low nitrogen and phosphorus nutrients,the density of Microcystis aeruginosa was low,the cell diameter was reduced,the content of malondialdehyde and the content of EPS were high,which favors the formation of colony.Phosphorus has a greater influence on the growth of Microcystis cells.Increased level of nitrogen and phosphorus nutrition,weakening of allelochemicals of the Zizanialatifolia on Microcystis aeruginosa cells.Phosphorus has greater effect on the Zizanialatifolia allelopathic algae,the density of the Microcystis aeruginosa is low under phosphorus limitation,the cell diameter is reduced,and the content of malondialdehyde is high.However,the content of extracellular polysaccharides is low and it is not easy to form colony.