适用于青萍修复的水体富营养化状况研究

Suitable eutrophication level for restoration by Lemna minor

为了分析青萍适合应用于何种富营养化程度地表水体的修复,研究水体富营养化的限制因子磷对青萍生长的影响.在其他条件不变的情况下,设计0.01、0.2、0.5、5、50 mg/L 5个磷质量浓度进行研究.测定叶状体数目相对增长率、根长、叶绿素a含量、可溶性蛋白含量以及抗氧化酶系统的几种酶,包括过氧化物酶(POD)活性、过氧化氢酶(CAT)活性以及丙二醛(MDA含量).将宏观的生长指标和细胞水平的保护酶活性的变化结合,研究青萍适合于何种磷质量浓度的富营养化水体的治理和生态修复中.结果表明,青萍可以生长的磷质量浓度范围很广.在所设计的5种磷质量浓度下,青萍均可生长,但青萍适合生长于磷质量浓度在0.2-5 mg/L(尤其是0.5 mg/L左右)的水体环境中.该植物适合应用于富营养化水平较高的水体环境中,适合于中国大多数湖泊等地表水体的治理和生态修复中.

The suitable level of phosphoric concentration duckweed. Lemna minor was cultured in the medium in natural waterbody was determined for the growth of containing five different phosphorus concentrations （0.01, 0. 2, 0. 5, 5, 50 mg/L）. Lemna minor can grow under all of these circumstances. The relative growth rate of frond number, soluble protein, root length, peroxidase（POD）, catalase（CAT） and malondialdehyde（MDA） were measured. The relative growth of frond number, chlorophyll a, soluble protein were higher when phosphorus concentration were 0. 2, 0. 5 and 5 mg/L. The POD activity, CAT activity and MDA content of Lemna minor grown in 0. 2, 0. 5 and 5 mg/L phosphorus concentrations were lower than those of grown in 0. 01 mg/L and 50 mg/L phosphorus concentrations. Lemna minor grown better when phosphorus concentration were 0. 2 to 5 mg/L（ especially about 0. 5 mg/L） than other phosphorus concentration. This study indicated that Lemna minor is suitable for recovering the eutrophicated nature waterbody in China.