中文摘要：

分析了铜和镉联合胁迫对羊角月牙藻（Selenastrum ca pricornutum）的影响,运用国内应用较少的新型技术——叶绿素荧光技术检测了胁迫下微藻的最大光能转化效率（Fv/Fm）受到的影响,并尝试通过膜脂过氧化损伤产物丙二醛（MDA）和其他指标在胁迫下的变化,对铜、镉联合胁迫机制进行初步探究.结果表明：（1）羊角月牙藻在铜、镉联合胁迫下生长受到抑制,表现出明显的浓度-效应关系.铜、镉的联合胁迫的相加指数为-1.63,表现为典型的拮抗作用.（2）通过叶绿素荧光技术的应用,探明Fv/Fm随毒性浓度的变化表现为浓度-效应关系,毒性浓度越大,羊角月牙藻的Fv/Fm越低,但在低毒性浓度刺激时随胁迫时间延长有回升迹象.（3）随毒性浓度的增加,羊角月牙藻的MDA增加,表现为显著的浓度-效应关系;可溶性蛋白质大体呈先升后降的趋势.（4）铜、镉联合胁迫下,MDA与羊角月牙藻生物量、Fv/Fm呈显著负相关.脂质过氧化是导致生物量下降和Fv/Fm受抑制的原因之一.（5）在微藻体内铜、镉发生拮抗作用的机制也可能与重金属的脂质过氧化作用由于拮抗受到抑制有关.

英文摘要：

The effect of copper-cadmium combined stress on Selenastrum capricornutum was investigated using novel chlorophyll fluorescence technique which less applied in domestic.The variation of maximal light energy conversion rate and malondialdehyde （MDA,a membrane lipid peroxidation product） under copper-cadmium combined stress was detected,base on which,the mechanism of copper-cadmium combination stress was preliminary discussed.The results show that：（1） the growth of Selenastrum capricornutum was inhibited under the copper-cadmium combined stress,and a dosage-effect relationship was clearly demonstrated.The additive index of copper-cadmium combined stress was-1.63,reflecting a typical antagonism of copper and cadmium.（2） There was a negative correlation between Fv/Fm value and toxic concentration,the higher the toxic concentration,the lower the Fv/Fm value would be.However,Fv/Fm value was slightly recovered as stress time increased under low toxic stress.（3） The MDA value of Selenastrum capricornutum was increased with the increasing of toxic concentration,and the content of soluble protein was first increased and then decreased in the gross.（4） Under the combined stress of copper and cadmium,MDA value was negative correlated with biomass and Fv/Fm value of Selenastrum capricornutum,membrane lipid peroxidation was one of the key reasons of the decreasing biomass and Fv/Fm inhibition.（5） The mechanism of antagonism between copper and cadmium might be related to the inhibition of membrane lipid peroxidationo.