Pb、Cd 胁迫对紫茎泽兰 N、P、K 吸收的影响

摘要

The effects of Pb,Cd on nutrient elements (N,P,K)uptake in different parts of Ageratina adenopho-rum were investigated in a soil pot experiment.The results showed that it had a positive effect on the absorption of N,P in different tissues under Pb stress,but negative effect on K uptake.Under the conditions of Cd stress,it was favorable for the absorption of N,P in different tissues,and the absorption of K was promoted at low Cd concentration,but inhibited at high concentration.It also had a positive effect on the absorption of N in different tissues under combined Pb-Cd pollution stress,but negatively affected K uptake.A large quantity of N and P was absorbed to alleviate the toxic effects on A.adenophorum by heavy metals.It is a possible tolerance mechanism of E .adenophorum under Pb and Cd stresses.%采用模拟 Pb、Cd 污染土壤培养法研究了紫茎泽兰在重金属 Pb、Cd 胁迫下植株不同部位对3种营养元素（N、P、K）吸收的影响。结果表明，紫茎泽兰各组织在 Pb 胁迫下对 N、P 的吸收总体上均保持一定的促进作用，对 K则表现出一定的抑制效应；Cd 胁迫下对 N、P 有良好的吸收，低浓度 Cd 促进 K 的吸收，高浓度则表现出抑制作用。Pb-Cd 复合污染胁迫下根茎叶均对 N 的吸收有一定的促进作用，而对 K 的吸收有较强的抑制效应。这表明，紫茎泽兰在重金属 Pb、Cd 胁迫下可通过大量吸收 N、P 等元素来有效缓解重金属的毒害作用，这可能也是紫茎泽兰能适应高 Pb、Cd 胁迫的一种耐性机制。