重金属Cd·Pb污染土壤对紫花苜蓿种子萌发和幼苗生长的影响  

Effects of Heavy Metal Cd,Pb Contamination on Seed Germination and Seedling Growth of Alfalfa

作　　者：景俏丽 董岁明[1,2] 侯琪琪 JING Qiao-li1,2 ,DONG Sui-ming1,2 ,HOU Qi-qi1,2(1. School of Environmental Science and Engineering,Chang＇ an University,Xi＇ an,Shaanxi 710054;2.Key Laboratory of the Ministry of Education for Underground Hydrology and Ecological Effect in The Dry Area,Chang＇an Uni-versity,Xi＇an,Shaanxi 71005)

机构地区：[1]长安大学环境科学与工程学院,陕西西安710054 [2]旱区地下水文与生态效应教育部重点实验室,长安大学,陕西西安710054

出　　处：《安徽农业科学》2018年第22期119-121,124,共4页Journal of Anhui Agricultural Sciences

基　　金：国家自然科学基金项目(41572236)

摘　　要：[目的]研究重金属Cd、Pb单一及复合污染对紫花苜蓿种子萌发和幼苗生长的影响。[方法]以紫花苜蓿(Medicago sativa)种子为材料,采用土培方法研究了重金属Cd、Pb单一及其复合污染土壤对苜蓿种子萌发及幼苗生长的影响。用种子的发芽势、发芽率、发芽指数与活力指数4个指标衡量种子的萌发状况。[结果]中低浓度的Cd、Pb对苜蓿种子萌发影响不大,当Cd≤15 mg/kg、Pb≤600 mg/kg时,种子的发芽势和发芽率与对照相比差异较小。重金属Cd、Pb严重阻碍了幼苗期苜蓿的正常生长,苜蓿的根长、芽长与鲜重这3项指标均与重金属浓度呈极显著负相关,相关系数远小于-0.900。[结论]Cd、Pb单一及其复合污染对苜蓿幼苗生长期的毒害作用远大于对种子萌发期的影响,苜蓿种子在前期萌发阶段对重金属Cd、Pb具有较强的耐性。[Objective]To study effect of heavy mental Cd,Pb single and compound pollution on seed germination and seedling growth of Alfalfa.[Method]Alfalfa seeds are used to study effects of heavy metal elements Cd and Pb on seed germination and seedling growth by using soil cultureexperments.The germination status of seeds was measured by germination energy,germination rate,germination index and vitality index.[Result]Cd and Pb in low concentration had little effect on the germination of alfalfa seeds.The germination energy and germination rate of the seeds werevery small compared with that of the control group when the Cd was less than 15 mg / kg and Pb was less than 600 mg / kg.The growth of alfalfaseedling stage was reflected by root length,sprout length and fresh weight.The heavy metal Cd and Pb seriously hindered the normal growth of see-ding period of alfalfa .The root and sprout length and fresh weight of alfalfa were significantly negatively correlated with the concentration of heavymetals,and the correlation coefficient was far less than -0.900.[Conclusion]Cd and Pb have more toxic effects on the growth of alfalfa seedlingsthan the effect on seed germination period.So the seed of alfalfa has strong tolerance to the heavy metal Cd and Pb during the germination stage.

关 键 词：紫花苜蓿 种子萌发 幼苗生长 

分 类 号：X5[环境科学与工程—环境工程]