Abstract: The pot experiment was conducted to study the physiological response of perennial ryegrass (Lolium perenne L.) and tall fescue (Festuca elata Keng ex E. alexeev) to the Pb-Zn-Cd compound pollution containing lead (Pb,337 mg·kg^-1),zinc (Zn,648 mg·kg^-1),and cadmium (Cd,9 mg·kg^-1),under single- and mixed-sowing conditions. The results showed that,under Pb-Zn-Cd stress,tall fescue exhibited higher stress resistance under single-sowing condition,and perennial ryegrass received higher resistance to heavy metal pollution after the mixed-sowing of two species at 1:1 ratio. It was observed that imbalance of active oxygen metabolism and damage to plants caused by water shortage were both alleviated due to induction of perennial ryegrass's active oxygen scavenging system and increased contents of soluble sugar and protein,under Pb-Zn-Cd stress. The toxic effects caused by Pb-Zn-Cd stress were reduced by increasing the contents of non-protein sulfhydryl and reduced glutathione. Finally,the resistance of tall fescue to Pb-Zn-Cd was not significantly improved under mixed-sowing condition.

Key words: Perennial ryegrass, Tall fescue, Mixed sowing, Heavy metal pollution, Physiological response

摘要： 通过盆栽试验，研究铅(Pb，337 mg·kg^-1)、锌(Zn，648 mg·kg^-1)、镉(Cd，9 mg·kg^-1)复合污染条件下，多年生黑麦草(Lolium perenne L.)单种、高羊茅(Festuca elata Keng ex E. Alexeev)单种以及多年生黑麦草和高羊茅混种(1∶1)方式下，多年生黑麦草和高羊茅对Pb-Zn-Cd复合污染的生理响应。结果显示:在Pb-Zn-Cd复合胁迫下，高羊茅单种具有较好的抗逆性，多年生黑麦草和高羊茅1∶1混种使多年生黑麦草有较好的抗逆性。结果表明：在Pb-Zn-Cd污染下，混种提高了多年生黑麦草对重金属污染的抗性，通过诱导多年生黑麦草活性氧清除系统以及可溶性糖和可溶性蛋白含量的增加来应对Pb-Zn-Cd胁迫带来的活性氧代谢失衡和缺水对植物的伤害，通过提高多年生黑麦草非蛋白巯基和还原型谷胱甘肽的含量来缓解Pb-Zn-Cd胁迫带来的毒性效应；混种高羊茅对Pb-Zn-Cd的抗性在Pb-Zn-Cd胁迫下没有显著提高。

关键词: 多年生黑麦草, 高羊茅, 混种, 重金属污染, 生理响应