穗花狐尾藻对铵态氮的生理响应

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SN₁2211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.

Physiological responses of Myriophyllum spicatum to ammonium nitrogen

With the sediment applied with 0,0.24%,and 0.48% NH_4Cl(treatments CK,SN_1,and SN_2) as the substrate,a greenhouse experiment was conducted to study the physiological responses of Myriophyllum spicatum to ammonium nitrogen.The NH_4~+-N concentration in the sediment,pore-water,and overlying-water ranged in 12.35-870.32 mg·kg~(-1),1.09-1036.05 mg·L~(-1),and 0.10-24.30 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.The SOD activity in M.spicatum leaves and roots was SN_1