铜、镉、铅、锌对4种豆科植物种子萌发的影响

Effects of Heavy Metals Copper,Cadmium,Lead and Zinc on Seed Germination and Seedling Growth of Leguminous Species

筛选和研究适合当地气候与土壤条件的重金属耐性植物,是对重金属污染土壤进行植物修复的前提。以蒸馏水为对照,采用培养皿法研究了Cu^(2+)、Cd^(2+)、Pb^(2+)和Zn^(2+)单一重金属对4种豆科植物种子萌发和幼苗生长的影响。结果表明,随着Cu^(2+)、Cd^(2+)、Pb^(2+)和Zn^(2+)浓度的增大,红豆草(Onobrychis viciaefolia Scop.)、白三叶(Trifolium repens L.)、柠条(Caragana Korshinskii Kom.)、胡枝子(Lespedeza bicolor Turcz.)的发芽率、发芽势呈不同程度的降低趋势;但在Cu^(2+)<300mg/L处理下,红豆草种子的发芽率并没受到明显抑制,反而有不同程度地促进;在Cd^(2+)处理下,25mg/L浓度对柠条种子萌发促进作用最为显著,柠条种子发芽率与对照相比达到显著性差异水平(p<0.05);Pb^(2+)对柠条和胡枝子种子的发芽率种子的发芽表现为"低促高抑"。Cu^(2+)、Cd^(2+)、Pb^(2+)和Zn^(2+)对4种植物根系生长均表现出强烈的抑制作用。随着Cu^(2+)、Cd^(2+)、Pb^(2+)和Zn^(2+)离子浓度的增大,红豆草、白三叶、柠条和胡枝子种子萌发后形成幼苗的根长和苗长都呈降低趋势,对4种植物均表现为随着浓度增加,抑制作用越明显。

Screening and study of heavy metal tolerant plants suitable for the local climate and soil condition is the premise of phytoremediation to heavy metal contaminated soil. In this study, the effects of Cu^2＋ ,Cd^2＋ ,Pb^2＋ and Zn^2＋ single heavy metals on seed germination and seedling growth of 4 legume species were studied by the method of culture dish. The results show that with the increase of Cu^2＋ ,Cd^2＋ ,Pb^2＋ and Zn^2＋ concentration, the germination rate, germination potential of Onobrychis viciaefolia Scop., Trifolium repens L., Caragana Korshinskii Kom. and Lespedeza bicolor Turcz. were reduced. The seed germination percentage of Onobrychis viciaefolia Scop. under 300 mg/L concentration was significantly higher than control. The seed germination percentage of Caragana Korshinskii Kom.under 25 mg/L concentration was significantly higher than control（p〈0.05） ;All the metals showed toxicity to root growth and shoot length of four plant species.The seedling root length and shoot length of four plant species was decreased with the increase of Cu^2＋ .Cd^2＋ .Pb^2＋ and Zn^2＋ concentration significantly.