不同磷浓度和光照培养对密刺苦草及附生席藻生长的影响OA

Light and nutrient salts are important environmental factors affecting the restoration and reconstruction of submerged macrophyte in eutrophic water.In order to explore the impacts of light intensity and exogenous phosphorus addition on submerged plants and epiphytic cyanobacteria,the physical and chemical factors,biomass and coverage of Phormidium sp.and physiological indicators of Vallisneri denseserrulata Makino(V.denseserrulata Makino)in water under different light intensity(30～115 μmol·m-2·s-1)and phosphorus concentration(0～10 mg·L-1)were determined by laboratory simulation experiments with V.denseserrulata Makino and their epiphytes as the research objects.The results showed that the biomass and coverage of Phormidium sp.increased by 74.5％and 57.5％respectively under strong light compared with low light,indicating that the biomass of Phormidium sp.increased with the increase of light in a certain range.In the early stage of the experiment,the addition of high concentration of exogenous phosphorus caused a rapid increase in the biomass of Phormidium sp..At the same time,it was found that with the increase of light and phosphorus nutrient concentration,Phormidium sp.transformed from attached biofilm to planktic algal gonium,and the influence of light on the life pattern of Phormidium sp.was significantly greater than that of phosphorus nutrient salt(P＜0.05).Compared with low light,the root length,root number and dry weight of V.denseserrulata Makino increased by 74.6％,54.2％and 43.6％,respectively,under high light,indicating that low light inhibited the root length.At the same time,under the condition of high concentration of phosphorus nutrients,the biomass was accumulated by reducing root length to increase plant number,plant height and root number.