紫萼玉簪种子和幼苗对酸雨与镉复合污染的生理生态响应  

Physio-ecological responses of seeds and seedlings of Hosta ventricosa to combined pollution of simulated acid rain and cadmium

作　　者：罗良旭 高素萍[1,2] 王成聪[1] 雷霆[1,2] 闻金燕[1] 罗雁[1] 

机构地区：[1]四川农业大学风景园林学院,成都611130 [2]四川农业大学园林研究所,成都611130

出　　处：《浙江大学学报（农业与生命科学版）》2017年第2期192-202,共11页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：四川省教育厅项目"乡村景观植物蓝雪花的高效快繁体系建立研究"(JGYQ2016010);四川省科技计划项目"突破性竹类(花卉)育种材料与方法创新"(2016NYZ0038)

摘　　要：为了解紫萼玉簪生长初期对酸雨与镉(Cd)复合污染的生理生态响应,探究该物种在复合污染下的自我更新能力,分别以紫萼玉簪种子和幼苗为供试材料,采用2因子5水平完全随机试验,研究不同梯度(pH分别为6.5、5.5、4.5、3.5、2.5)模拟酸雨与不同质量浓度重金属Cd^(2+)(0、10、30、50、100 mg/L)复合污染胁迫下,该植物种子和幼苗的生理生态指标变化。结果表明:酸雨和Cd复合污染比单一污染对紫萼玉簪种子和幼苗造成的伤害更大,两者之间交互作用显著,表现为协同作用,且这一作用在高强度复合污染下表现得尤为突出;紫萼玉簪种子和幼苗对低强度酸雨和低质量浓度Cd胁迫有一定的耐受性,其中,低质量浓度Cd^(2+)(10 mg/L)处理对种子萌发表现出一定的促进作用。幼苗对Cd胁迫的耐受能力弱于成苗,在本试验条件下,耐受的临界质量浓度值为30 mg/L。过氧化氢酶活性对Cd污染胁迫的敏感性高于超氧化物歧化酶,尤其在与酸雨复合作用下敏感性增加,表现在重金属Cd^(2+)质量浓度为30 mg/L时就到达峰值,这也进一步导致其在高质量浓度Cd^(2+)污染时对活性氧的清除能力下降,使活性氧的产生速率超过抗氧化酶系统的清除能力,从而使幼苗完全丧失了自我保护的能力。综合各指标结果认为,紫萼玉簪种子萌发和幼苗生长分别在低强度酸雨(pH≥5.5)与低质量浓度Cd^(2+)(≤10和30 mg/L)污染胁迫下能顺利进行自我更新,而高强度复合污染对种子萌发和幼苗生长极为不利。该研究结果对复合污染地区的土壤环境修复工作具有一定的参考价值。Summary The combined pollution of acid rain and cadmium （Cd） has been an important component of soil interacted with atmospheric pollution in China. The combined pollution posed harmful impact on human beings, and threatened the habitats of other creature, such as the urban garden plants. Therefore, it is important to investigate the effect of complicated pollution on plant growth, extension of plant population and ecosystem balance. The seed germination is the origin of the plant＇ s life cycle, which is the key link affecting extension of plant population. The stress resistance was bad in the seeding stage, especially poorer resistance to single and combined pollution compared to seedling stage. Therefore, the seeding period became the key to accomplish extension of plant population under habitat destruction. Previous studies on Hosta ventrlcosa focused on single pollution of Cd or acid rain; recently H. ventricosa was found to have tolerance against combined pollution of Cd and acid rain. Therefore, it is potential for phytoremediation of Cd polluted soil in acid rain area. In this study, El. ventricosa was selected as test material, to investigate the physico-ecological responses under combined pollution of simulated acid rain and Cd. The tolerance of H. ventricosa was examined under both seed germination and seedling periods, to provide science evidence for selection of urban plants with strong stress resistance under combined pollution. A completely random scheme of two factors （simulated acid rain and Cd） and five levels was used. The simulated acid rain was set at five pH levels （6.5, 5.5, 4.5, 3.5 and 2.5）, and the Cd treatment fluids were set at five different Cd2 concentrations （0, 10, 30, 50 and 100 rag/L）. Both normal and abnormal germination rates were measured in each group. Meanwhile, after the seedling of H. ventricosa grew up to 10 to 15 em height, the contents of chlorophyll, malondialdehyde （MDA） and H202, the activities of peroxidase （POD）, superoxide dismutase （S

关 键 词：镉 酸雨 复合污染 生态胁迫 抗性生理 紫萼玉簪 

分 类 号：S682.19[农业科学—观赏园艺]