重金属对莴苣种子萌发和幼苗生长的影响

Effects of Heavy Metals on Seedling Growth and Seed Germination of Lettuce Seeds

以莴苣(Lactuca sativa L.)种子为材料,采用水培方法研究了重金属Cu、Cr、Pb对莴苣种子萌发和幼苗生长的影响。结果表明,低浓度(10 mg/L)的Cu能促进莴苣种子萌发和幼苗生长,在高浓度时对莴苣生长有抑制作用。Cr对莴苣种子萌发和幼苗生长表现出的抑制作用最为明显,且随其浓度的升高,抑制作用急剧上升。Pb对莴苣种子萌发有延迟作用,对幼苗生长抑制作用明显。经3种不同重金属处理后的莴苣种子,幼苗根长、芽长随着重金属浓度的增加而降低(10 mg/L Cu处理除外),3种重金属对其毒害作用从大到小的顺序为Cr、Pb、Cu。

Lettuce seeds were used to study the effects of heavy metal elements Cu, Cr and Pb on seed germination and seedling growth with hydroponic experiments. Results showed that the low concentration（10 mg/L） of Cu promoted lettuce seed germination and seedling growth. High concentration Cu inhibited the growth of lettuce. The inhibitory effect of Cr was the most obvious. With the increase of the concentration, the inhibition increased sharply. Pb had a delayed effect on lettuce seed germination. The seedling growth inhibitory effect was obvious. The root length of seedling and the length of shoot decreased with the increase of salt concentration of heavy metals（except the treatment of 10 mg/L Cu）. The toxicity of three kinds of heavy metal salts was in order of CrPbCu.