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期 刊 ：应用生态学报 2009年 20卷 09期 页码：2283-2288

关键词：铵态氮；穗花狐尾藻；生理响应；抗氧化酶；

Keywords:ammonium nitrogen, Myriophyllum spicatum, physiological response,

摘 要 ：

在温室内，以原沉积物(CK)和分别添加0.24%与0.48%氯化铵(SN₁和SN₂)的沉积物作为底质培养沉水植物，研究了穗花狐尾藻对高浓度铵态氮胁迫的生理响应.结果表明:不同处理沉积物、间隙水和上覆水中铵态氮浓度分别在12.35～870.32 mg·kg^-1 、1.09～1036.05 mg·L^-1和0.10～24.30 mg·L^-1，与CK相比，SN₁和SN₂处理的穗花狐尾藻生物量、株高和根长分别降低了19.69%和81.16%、15.66%和55.52%与45.72%和67.65%.不同处理根系和叶片SOD活性均表现为SN₁<SN₂<CK；叶片过氧化物酶(POD)和过氧化氢酶(CAT)活性均表现为SN₂<SN₁<CK，但SN₁和SN₂根系POD和CAT活性则显著高于CK；SN₁、SN₂叶片和根系丙二醛(MDA)含量分别比CK提高了46.30%、82.75%和19.66%、55.19%.不同浓度铵态氮对穗花狐尾藻均具有毒害作用，而且铵态氮浓度越高，植物生理响应越明显.

Abstract:

With the sediment applied with 0, 024%, and 048% NH4Cl (treatme
nts CK, SN1, and SN2) as the substrate, a greenhouse experiment was conducte
d to study the physiological responses of Myriophyllum spicatum to ammonium nitr
ogen. The NH4+-N concentration in the sediment, pore-water, and overlying
-water ranged in 1235〖KG-*2〗-〖KG-*7〗87032 mg·kg-1, 109〖KG-*2
〗-〖KG-*7〗103605 mg·L-1, and 010〖KG-*2〗-〖KG-*7〗2430 mg·L-1
, respectively. Comparing with those in CK, the plant height, root length, and
 fresh biomass of M. spicatum in treatments SN1 and SN2 decreased by 15
66% and 5552%, 4572% and 6765%, and 1969% and 8116%, respectively. T
he SOD activity in M. spicatum leaves and roots was SN1<SN2<CK, but the
peroxidase (POD) and catalase (CAT) activities in the leaves were SN2<SN1<CK， while those in the roots were significant higher in SN1 and SN2 than in CK.
 The malondialdehyde (MDA) contents of leaves and roots in SN1 and SN2 were
increased by 4630% and 8275%, and 1966% and 5519%, respectively. It was
suggested that NH4+-N had toxic effects on M. spicatum, and the higher
the NH4+-N concentration in sediment, the more obvious the physiological re
sponses of M. spicatum exhibited.

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