不同营养状态下金鱼藻的生理响应

通过静态模拟实验，比较研究了不同营养水平（中营养、富营养、重富营养和Hoagland植物培养液）下培养的金鱼藻（Ceratophyllum demersum）的蛋白质、叶绿素含量，过氧化物酶（POD）及超氧化物酶（SOD）活性变化.研究发现，总N、总P 的变化会影响金鱼藻的生物合成，当水环境总氮浓度低于1 mg·L^-1，总磷浓度低于0.1 mg·L^-1时，金鱼藻茎叶的叶绿素合成较低，其茎蛋白含量迅速下降.金鱼藻在富营养水平（1 mg TN·L^-1， 0.1 mg TP·L^-1）下抗氧化防御酶活跃，POD、SOD活性增高.研究表明，金鱼藻较适应于富营养水环境，水体营养盐继续增加对金鱼藻有胁迫作用，过高营养盐浓度（重富营养和Hoagland培养液）影响金鱼藻的抗逆能力.

Physiological responses of Ceratophyllum demersum under different nutritional conditions

With static experiments, this paper investigated the protein and chlorophyll contents, and the peroxidase (POD) and superoxide dismutase (SOD) activities of Ceratophyllum demersum cultured in meso-, eutro- and hypertrophic and Hoagland's solutions. The results showed that the changes of total N (TN) and total P (TP) concentrations in nutrient solutions had an obvious effect on the biosynthesis of C. demersum. When the concentrations of TN and TP were less than 1 mg x L(-1) and 0.1 mg x L(-1), respectively, the protein and chlorophyll contents of plant declined. The plant from eutrophic solution had higher SOD and POD activities. It was indicated that C. demersum was more preferable to eutropic condition (1 mg TN x L(-1) and 0.1 mg TP x L(-1)), and the raised concentration of nutrients (e. g., hypertrophic and Hoagland's solutions) was a stress to C. demersum and could affect its hardiness physiology.