黑麦草对土壤中Pb的富积作用及耐受性研究

A Study on Pb Accumulation and Tolerance of Lolium Perenne L.in Soil

通过土培实验研究了在单一因素影响下,不同浓度的Pb对黑麦草种子萌发及幼苗生长的影响,同时测定了其抗性生理指标的改变以及地上部分和根系对Pb的富集作用。实验结果表明,低浓度的Pb(<500mg/kg)单一污染时,对黑麦草种子萌发及幼苗生长有促进作用。高浓度时有显著的抑制作用,且随着浓度的升高(500～2000mg/kg),抑制作用和毒害作用都加强,各项指标均出现显著降低。同时,随Pb浓度增加,丙二醛(MDA)和可溶性糖含量显著增加,呈极显著正相关。叶片光合色素含量先增后减,呈负相关。黑麦草对Pb有一定的富集能力,当Pb浓度为500mg/kg时,地上部分相对累计量达到最大。

The experiment with specially treated soil aimed to study the effects of different concentrations of Pb on seed germination and seedling growth, and to analyze the change of eco-physiological index and Pb contents in aboveground part and roots of Loliurn perenne. Results showed that at the lower concentration of Pb （~500 mg/kg）, seed germination and seedling growth of Lolium perenne were improved observably, but at the higher concentration of Pb （500-2 000 mg/kg）, seed germination and seedling growth were restrained distinctly. The restraining effect was intensified with the increase in Pb concentration. Meanwhile, MDA and soluble monosaccharose contents were increased with the increase in Pb concentration. Chlorophyll content of leaves appeared to increase at the beginning stage and then decreased. Lolium perenne had some of enrichment capability. When Pb concentration was 500 mg/kg, relative accumulation of the aboveground part reached its maximum.