EDTA对镉胁迫下紫云英种子萌发及幼苗生理抗性的影响

Effects of EDTA mixed Cadmium Stress on the Seed Germination an Physiological Resistance Characters of Initial Growth in Astragalus sinicus

采用水培法研究不同浓度EDTA(乙二胺四乙酸)对镉胁迫下紫云英(Astragalus sinicus L.)种子萌发及幼苗生理抗性的影响,为重金属污染植物复合修复提供科学依据。结果表明:单一的镉(浓度为100 mg/L)胁迫紫云英时,能促进种子萌发,增加幼苗中丙二醛(MDA)的含量以及过氧化物酶(POD)的活性,但是会抑制幼苗的生长、降低幼苗的叶绿素含量以及超氧化物歧化酶(SOD)的活性。当在镉溶液中添加不同浓度的EDTA时,随着EDTA浓度的增加,其种子发芽率、幼苗长势、叶绿体含量以及POD活性都呈现出先增加后降低的趋势。就供试材料而言,在一定浓度范围内的EDTA能缓解镉胁迫紫云英幼苗的伤害作用,其中以0.05 mmol/L的EDTA处理效果最为明显。

The effects of different concentrations of EDTA（ ethylene diamine tetraacetic acid） on theseed germination and seedling physiological resistance of Astragalus sinicusunder cadmium （Cd） stress were studied by hydroponic method to provide scientific basis for remediation of heavy metal polluted plants. The results showedthat single cadmium stress （ 100 mg/L） promoted the seed germination, increased the seedling malondialdehyde （MDA） content and peroxidasc （POD） activity, but inhibited the seedling growth, reduced the seedling chlorophyll content and the superoxide dismutase （SOD） activity. When different concentrations of EDTA were added into Cd solution and with the increase of EDTA concentra- tion, the seed germination rate, seedling growth, chloroplast content and POD activity first increased and then decreased. Therefore, certain range of concentrations of EDTAcould relievethe damage of Astragalus sinicus seedlingsinduced by Cd stress, with the treatment of EDTAconcentration at 0.05 mmol/Lbeing the most effective.