【摘要】 采用土培模拟方法研究了不同浓度Cd(0~50 mg/kg)对桐花树(Aegiceras corniculatum)土壤酶活性的影响.试验结果表明:低浓度Cd(0.5 mg/kg)胁迫,可刺激脲酶的活性;在高浓度Cd(20~50 mg/kg)处理条件下,脲酶、蛋白酶、蔗糖酶、过氧化物酶活性均受到不同程度的抑制,最大抑制率均达到25%以上;Cd处理对过氧化氢酶活性无显著影响.相关分析表明,Cd处理浓度与土壤酶活性间均存在显著负相关关系,相关程度为:脲酶>蛋白酶>过氧化物酶>蔗糖酶>过氧化氢酶;脲酶、蛋白酶、蔗糖酶、过氧化物酶4种酶的活性间呈显著正相关,表明这4种酶对Cd胁迫有相似的适应性.脲酶对Cd的影响作用最为敏感,建议用脲酶作为Cd对桐花树湿地污染的指示酶.更多还原

【Abstract】 To study the effects of cadmium(Cd) on the enzymatic activity of Aegiceras corniculatum soil,propagules of A.corniculatum were cultivated in soil supplied with various concentrations of Cd(0~50 mg/kg).The results showed that soil urease activity was increased under low level of Cd(0.5 mg/kg) treatment.Under conditions of higher Cd concentrations(20~50 mg/kg),the activities of soil enzymes(urease,protease,peroxidase and invertase) were inhibited,and the maximum rates of inhibition were over 25%.No significant differences of catalase activities were found among different treatment in this study.Significant negative correlationships were found between soil Cd concentrations and activities of the five soil enzymes,and the order of correlation was: urease > protease> peroxidase > invertase> catalase.Meanwhile,significant positive correlationships between enzymatic activities were found in this study except catalase,this may suggest that these four enzymes have similar response patterns to Cd pollution.Urease was mostly sensitive to Cd among these four enzymes,it may be used as the index to screen the pollution of Cd in mangrove wetlands.更多还原