Pb污染土壤对高羊茅种子萌发及幼苗生长的影响

Effects of Soils Contaminated by Lead on Germination and Seedling Growth of Festuca arundinacea L.

通过土培研究了在单一因素影响下,不同浓度的Pb对高羊茅种子萌发及幼苗生长的影响,同时分析测定了其抗性生理指标的改变以及地上部分和根的Pb累积量。实验结果表明:低浓度的Pb(<100 mg.kg-1)单一污染时,对高羊茅种子萌发及幼苗生长的初期有促进作用(P<0.05);高浓度时有显著的抑制作用(P<0.05),且随着浓度的升高(200～2 000 mg.kg-1),抑制作用和毒害作用都加强。同时,随Pb浓度增加,叶片和根中的Pb含量也增加,叶片的细胞膜透性增大,电导率显著升高;MDA含量和抗氧化保护酶POD活性先略微降低,而后也呈增大趋势。

The effects of lead （Pb） of different concentrations on germination, seedling growth, physiological response and Pb contents in shoot and root of Festuca arundinacea L. were studied by means of soil cultivation experiment. The results showed that under treatment of low concentration of Pb （〈100 mg·kg^-1）, the germination and seedling growth in initial stages of Festuca arundinacea L. were promoted significantly （P〈0.05）, but under treatment of high concentration of Pb （500-2 000 mg·kg^-1）, the germination and seedling growth were restrained significantly （P〈0.05）, and with the increasing of Pb concentration, the restraining effects was intensified. Pb contents in shoot an root, character of membrane permeability and electric conductivity increased, while MDA content , activity of POD appeared to decrease at the growth of beginning stage and then increased at growth of late stage.