摘要
【目的】探究重金属铜、铅、锌胁迫对药用植物黄芪植物种子萌发、生根、叶片叶绿素含量和DNA损伤的影响,为黄芪无公害栽培和药材基地环境评价提供理论依据。【方法】以内蒙特色药用植物黄芪为材料,设置不同浓度重金属(0～300mg/L)单一和复合污染(Zn200/Cu200、Zn200/Pb200、Pb200/Cu200mg/L),观察黄芪生长状况及其叶片叶绿素含量的变化,并利用单细胞凝胶电泳技术检测黄芪DNA损伤情况。【结果】在0～100mg/L时,Cu2+、Pb2+、Zn2+单一胁迫可促进黄芪种子萌发,大于100mg/L时则抑制种子萌发。随着黄芪培养时间的延长和重金属离子处理浓度的升高,Pb2+处理的黄芪根生长受抑制逐渐增强,黄芪根长变短;Cu2+、Zn2+处理的黄芪根长呈先升高后降低的趋势,在不同时期内两者最长根长出现的处理浓度分别为60和100mg/L。3种重金属Cu2+、Pb2+、Zn2+单一处理后,黄芪总叶绿素含量呈先增后降的变化趋势,当Cu2+处理浓度高于100mg/L、Zn2+处理浓度高于200mg/L、Pb2+处理浓度高于60mg/L时,黄芪叶片叶绿素含量最高,随后不断降低。Cu/Zn、Zn/Pb复合胁迫,会降低彼此的毒害作用;Cu与Zn复合胁迫,对彼此毒害作用影响不大。随着重金属Zn2+、Pb2+、Zn2+浓度的增加,对黄芪DNA的伤害程度不断加大,Pb2+处理造成的损伤最大,Cu2+处理次之,Zn2+处理最小。【结论】一定含量的Pb2+、Cu2+、Zn2+对药用植物黄芪种子萌发、生根、叶绿素含量具有一定毒害作用,且随重金属浓度的增加,毒害程度加深。3种重金属离子的毒性大小排序为Pb2+>Cu2+>Zn2+。
[Objective ]The present experiment was aimed to provide theoretical references for the pollution-free culti- vation of Astragalus membranaceus （Fisch.） Bge. Varmongholicus （Bge.） Hsiao and the evaluation of Astragalus membranaceus base environment by exploring the effect of copper, lead and zinc on seed germination, rooting, chlorophyll content and DNA damage in medicinal plants Astragalus membranaceus. [Method]Inner Mongolia special medicinal plants Astragalus membranaceus were used as testing material. The single concentration（0-300 mg/L） and combined concentration （Zn 200/ Cu 200, Zn 200/Pb 200, Pb 200/Cu 200 mg/L） of heavy metal were designed to treat the seed and seedlings of Astragalus membranaceus. The growth status and chlorophyll content of Astragalus membranaceus were monitored, and the DNA damage of Astragalus membranaceus was detected using the single cell gel electrophoresis technique. [Result]Within 0-100 rag/L, single stress of Cu^2＋, Pb^2＋ or Zn^2＋ could promote seed germination, while over 100 mg/L it did the opposite. With the increase of the concentration of Pb2＋ and stress duration, Astragalus membranaceus growth was inhibited with root short- ened. The growth of Astragalus membranaceus root treated by Cu^2＋ and Zn^2＋ was promoted first but inhibited later. In dif- ferent period, the longest root was got at 60 and 100 mg/L of Cu^2＋ and Zn^2＋, respectively. After being treated by Cu^2＋, Pb^2＋ and Zn^2＋ separately, the chlorophyll content of Astragalus membranaceus was increased first but decreased later. At over 100 mg/L of Cu^2＋,200 mg/L of Zn^2＋ and 60 mg/L of Pb^2＋, the chlorophyll content was the highest but then decreased. It re- duced each other＇s toxic effects in combined pollution of Cu^2＋ and Zn^2＋, Pb^2＋ and Zn^2＋. Little influence was found on each other＇s toxic effects in combined pollution of Cu^2＋ and Pb2＋. More concentrations of Pb, Cu and Zn induced more harm to the DNA of Astragalas membranaeeus; the harm of DNA induced by Pb^2＋ was the most, followed by Cu^2＋ and Zn^2＋. [Con- elusion]Certain toxicity on seed germination, rooting and chlorophyll of medicinal plants is induced by the certain content of Pb, Cu and Zn, and more concentration means more damage. The toxicity of the three heavy metal was Pb^2＋〉Cu^2＋〉Zn^2＋.
出处
《南方农业学报》
CAS
CSCD
北大核心
2013年第2期205-209,共5页
Journal of Southern Agriculture
基金
内蒙古自然科学基金项目(2010MS0510)
关键词
黄芪
重金属
生长状况
DNA损伤
彗星测试
Astragalus membranaceus
heavy metal
growth
DNA damage
comet test
