尿素态氮对金鱼藻生长与生理特性的影响

Effects of Urea-nitrogen on Growth and Physiological Properties of Ceratophyllum demersum

通过研究尿素形态氮对金鱼藻的生长与生理特性的影响,为合理利用金鱼藻来改善水质提供依据.通过静态模拟实验,设定不同的尿素态氮浓度,研究了对金鱼藻株高、生物量、存活率、质膜透性、叶绿素含量、超氧自由基的产生速率和超氧化物歧化酶(SOD)的影响.高浓度尿素态氮处理下金鱼藻株高、生物量、存活率明显下降,质膜相对电导率明显高于其它处理,超氧自由基的产生速率呈现先增大后减小的趋势,SOD表现出持续下降的趋势.当尿素态氮的浓度达到10 mg/L以上时,金鱼藻的生长受到明显的抑制,初步确定金鱼藻生长尿素态氮阈值浓度大约为15 mg/L.

The effects of urea-nitrogen on growth and physiological index and mechanism of Cerato- phyllum demersum were investigated to provide scientific basis for using Ceratophyllum demersum to improve water condition. Using static laboratory experiment, the effect of different urea-nitrogen concentrations on height, biomass, livability, chlorophyll content, selective permeability of cell, 02.-production rate and SOD activity of Ceratophyllum demersum were investigated. The height, the biomass and the survival percentage of Ceratophyllum demersum were significantly inhibited under high concentration of Urea-N. The membrane permeabilities of Ceratophyllum demersum in high concentration of Urea N were much higher than those of other treatments. The O2. -production rate increased at first but decreased later under high urea-nitrogen concentration. The activities of SOD decreased all the time under high urea-nitrogen concentration, when the concentration of urea-nitrogen was higher than 10 mg/L, the growth was decreased. The urea-nitrogen threshold was about 15 mg/L for growing of Ceratophyllum demersum.