铵氮和硝氮胁迫下金鱼藻对氮素的利用

Nitrogen Usage of Ceratophyllum demersum under Ammonia Nitrogen and Nitrate Nitrogen Stress

对剑湖优势沉水植物金鱼藻进行不同浓度的铵氮和硝氮耐受试验,同时对植物体内的总氮、硝氮、铵氮和可溶性蛋白含量进行测定和比较。结果显示,环境中的铵氮和硝氮直接影响金鱼藻对氮素的吸收利用,和对照相比,金鱼藻的总氮含量都有明显的升高,但是浓度对总氮含量影响不明显。金鱼藻对环境铵氮较敏感,环境中高浓度的铵氮会抑制氮素的转化。金鱼藻对硝氮的耐受能力较强,环境中低浓度的硝氮会促进金鱼藻对硝氮的吸收和转化,环境硝氮浓度达到60 mg/L时,金鱼藻对硝氮的吸收达到饱和,可溶性蛋白含量达到一定水平后不再随环境硝氮浓度增加而增加。

Ceratophyllum demersum,which is widely distributed in Jian Lake in Yunnan Province,was made tolerate different ammonia and nitrate concentrations.The total nitrogen,nitrate nitrogen,ammonia nitrogen and soluble protein of Ceratophyllum demersum were detected and compared.The results showed that nitrogen in the environment source directly affected the absorption and utilization of nitrogen by Ceratophyllum demersum.There existed an obvious rise of its total nitrogen compared with the control,but the influence of the concentration on its total nitrogen content was not obvious.Ceratophyllum demersum was sensitive to environmental ammonia nitrogen.High concentration of environmental ammonium nitrogen inhibited the transformation of nitrogen.The tolerance ability of Ceratophyllum demersum to nitrate nitrogen was high and low concentrations of nitrate nitrogen in environment could promote its nitrate uptake and transformation.The nitrate absorption of Ceratophyllum demersum saturated when the nitrate nitrogen concentration of environment reached 60 mg/L.The content of soluble protein above a certain level no longer increased with the environmental nitrate concentration.