富营养条件下不同形态氮对轮叶黑藻(Hydrilla verticillata)的生理影响

在实验室条件下,研究了在富营养水平(ρ(TN)为4.0 mg/L,ρ(TP)为0.2 mg/L)下不同ρ(NH₄+-N)/ρ(NO₃--N)(4/0,5/1,1/1,1/5,0/4)对沉水植物轮叶黑藻(Hydrilla verticillata)生理生化的影响,以期阐明富营养化水体中不同形态氮对沉水植物的影响.结果表明,不同ρ(NH₄+-N)/p(NO₃--N)对轮叶黑藻的生理活动和生长具有明显的影响,随着培养液中ρ(NH₄+-N)比例的上升,尤其当ρ(NH₄+-N)/ρ(NO₃--N)＞1时,轮叶黑藻的相对生长率、叶绿素含量和可溶性糖含量明显下降,谷氨酰胺合成酶(GS)和过氧化物酶(POD)活性升高,超氧化物歧化酶(SOD)活性下降,蛋白质含量降低.当水体中铵盐含量上升到一定比例时对轮叶黑藻产生的胁迫作用,影响了其生理功能,抑制其生长. 

Effects of Different Form of Nitrogen on Hydrilla verticillata under Eutrophic Nutrient Condition

Effects of different ratios of ρ(NH4+-N) to ρ(NO₃-—N)(4/0,5/1,1/1,1/5,0/4) on Hydrilla verticillata were investigated under eutrophic nutrient condition(ρ(TN) is 4.0 mg/L,ρ(TP) is 0.2 mg/L) in laboratory.Results showed that there were obvious effects of physiological activity and growth of Hydrilla verticillata cultured in different ratios of ρ(NH₄+-N)and ρ(NO₃-—N) solution.With the increase of proportions of NH4+-N in culture solution,especially when the ratio of ρ(NH₄+-N) to ρ(NO₃-—N) was higher than 1,the growth rate,the chlorophyll contents and the soluble sugar contents of Hydrilla verticillata decreased obviously,the protein contents and SOD activities deceased,and the activities of POD and GS increased.The results indicated that the raised NH4+-N mass concentrations in water could be a stress to Hydrilla verticillata.