Keywords: Lemna minor, Spirodela polyrhiza, phosphorus concentration, eutrophied waterbodies, eutrophication, ecological restoration, duckweed, China
The suitable phosphorus concentration level for restoration by duckweed
The suitable level of phosphorus concentration in waterbody was determined for the growth of duckweed. Lemna minor and Spirodela polyrhiza were cultured in medium containing five different phosphorus concentrations (0.01, 0.2, 0.5, 5 and 50 mg l−1). The increase of frond number, fresh weight, soluble protein, root length, peroxidase, catalase and malondialdehyde were measured. The two species of duckweed can survive under all circumstances. They grew better when phosphorus concentrations were 0.5-5 mg l−1 than other phosphorus concentrations. This study indicated that the two species of duckweed are suitable for recovering the eutrophicated natural waterbodies in China.