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在水培条件下,用浓度为0、500、1000和1500mg/L的Pb2+〔Pb(NO3)2〕处理高羊茅植株(Festucaarundinacea),研究铅污染对高羊茅植株生长的影响,以及NO3-、K+、Ca2+、Na+、Mg2+和Mn2+含量和Pb2+积累量的变化。结果表明,与对照相比,Pb2+胁迫下的高羊茅植株鲜重、干重、含水量和根系活力都下降,质膜透性呈上升趋势,MDA含量先略下降后升高;Pb2+胁迫下根和叶的NO3-、K+和Ca2+含量均低于对照,而根的Na+、Mg2+和Mn2+含量相比对照呈先上升后下降趋势,叶片的Na+、Mg2+和Mn2+含量则变化不大;与对照相比,根和叶的Pb2+含量、根Pb2+积累量急剧上升,叶和单株Pb2+积累量则先急剧上升后略下降;在浓度为1000mg/L Pb2+处理下,Pb2+积累率为55.74%。因此,高羊茅经Pb2+处理后,Pb2+在植株体内积累,引起根系活力下降,导致植株失水,氮素营养不足,细胞膜脂质过氧化作用加剧,干扰无机离子稳态等一系列伤害,这些伤害作用使植株生长受抑制,且这种抑制作用随着铅处理浓度的增加而加重。从植物修复的观点来说,对Pb污染的土壤,高羊茅是一种具有较大修复潜力的草坪草。
Festucaarundinacea was treated with Pb2 + [Pb (NO3) 2) at 0, 500, 1000 and 1500 mg / L in hydroponic culture to study the effect of lead contamination on the growth of tall fescue plants and the effects of NO3 -, K +, Ca2 +, Na +, Mg2 +, Mn2 + and Pb2 + accumulation. The results showed that compared with the control, the fresh weight, dry weight, water content and root activity of tall fescue plants under Pb2 + stress decreased, while the permeability of plasma membrane increased. MDA content slightly decreased and then increased. Under Pb2 + stress The contents of NO3-, K + and Ca2 + in roots and leaves were lower than those in the control, while the contents of Na +, Mg2 + and Mn2 + in roots were increased firstly and then decreased and the contents of Na +, Mg2 + and Mn2 + Compared with the control, Pb2 + content and Pb2 + accumulation in roots and leaves increased sharply, and the accumulation of Pb2 + in leaf and plant firstly increased sharply and then decreased slightly. Under Pb2 + concentration of 1000 mg / L, Pb2 + accumulation rate was 55.74%. Therefore, Pb2 + accumulation in tall fescue caused Pb2 + accumulation in plants, resulting in decreased root activity, leading to dehydration of plants, insufficient nitrogen nutrition, increased lipid peroxidation of cell membranes and interference with a series of injuries such as inorganic ion homeostasis. Injury caused the growth of plants to be inhibited, and this inhibition increased with the increase of lead concentration. From the point of view of phytoremediation, tall fescue is a turfgrass with great potential for remediation on Pb contaminated soil.