青萍(Lemna minor L.)对氮磷的吸收特征

以西部地区优势浮萍品种青萍为实验对象,研究了青萍对不同浓度硝态氮和磷酸盐的吸收特征。结果表明,硝态氮浓度在1～10 mg/L范围内,青萍对硝态氮有较好的吸收效果,M-M方程可以较好地描述硝态氮浓度与青萍对硝态氮的吸收速率之间的关系,通过M-M方程拟合得到青萍对硝态氮的最大吸收速率为0.1167 mg/(g FW.h),亲和力常数为6.9274。磷酸盐浓度在0.1～1.0 mg/L范围内,青萍对磷酸盐也有较好的吸收效果,二次多项式回归可以较好地描述青萍吸收速率与磷酸盐浓度的关系,回归方程得到青萍对磷酸盐的最大吸收速率为0.0193 mg/(g FW.h),对应磷酸盐浓度为0.6 mg/L。

Uptake characteristics of nitrate and phosphate by Lemna minor L.

As an advantage variety of duckweeds in the western region of China, Lemna minor L. was used to study its uptake kinetics of nitrate and phosphate. Results showed that Lemna minor L. had good ability to absorb nitrate (NO₃^--N), when the latter's concentration was 1~10 mg/L. Relationship between concentration and uptake rate of NO₃^--N could be illustrated with the Michaelis-Menten (M-M) equation. According the obtained results of M-M equation, the maximum uptake rate of NO₃^--N was 0.1167 mg/(g FW·h) while the affinity constant was 6.9274. Lemna minor L. also played important roles to absorb orthophosphate (PO₄^3--P), when the latter's concentration was 0.1~1.0 mg/L. The relationship between concentration and uptake rate of PO₄^3--P could be illustrated with two polynomial regressions. The maximum uptake rate of PO₄^3--P obtained by polynomial regression was 0.0193 mg/(g FW·h), where the concentration was 0.6 mg/L.