Abstract: The effects of Cd2+, Ni2+, Cr6+, Hg2+ and Pb2+ on sesame (Sesamum indicum) seed germination and seedling growth were researched. The results showed that heavy metal ions stresses had less influence on sesame seed germination and the most influence on radicel growth. With increasing concentration of heavy metal ions, sesame seedling shoot length, root length and seedling fresh weight decreased continuously. After seed germination, sesame radicle could not grow and seedlings did not survived with the concentration of Cd2+, Ni2+, Cr6+, Hg2+ or Pb2+ up to 20, 20, 20, 50 or 100 mg稬-1, respectively, which illustrated these concentrations could be used as lethal concentrations of sesame seed germination. By comparison, the toxicity degree of 5 kinds of heavy metal ions on sesame seed germination and seedling growth was Ni2+ > Cr6+ > Cd2+ > Hg2+ > Pb2+.

Key words: Sesamum indicum, seed germination, seedling growth, heavy metals, stress

摘要： 采用培养皿滤纸发芽法研究镉(Cd2+)、镍(Ni2+)、铬(Cr6+)、汞(Hg2+)、铅(Pb2+)等5种重金属离子对芝麻Sesamum indicum种子萌发及幼苗生长的影响。结果表明，重金属离子胁迫对芝麻种子露白萌发影响较小，对胚根生长影响最大；随着重金属离子浓度增加，芝麻幼苗芽长、根长和鲜重减小；在Cd2+、Ni2+和Cr6+浓度20 mg·L-1，Hg2+浓度50 mg·L-1，Pb2+浓度100 mg·L-1时，芝麻种子萌发后胚根基本不生长，难以成苗，这些浓度可视为对应重金属离子对芝麻种子萌发毒害的致死浓度。综合比较，5种重金属离子对芝麻种子萌发及芽期幼苗生长的毒害程度依次为Ni2+ > Cr6+ > Cd2+ > Hg2+ > Pb2+。

关键词: 芝麻, 种子萌发, 幼苗生长, 重金属, 胁迫