中文摘要：

以莴苣为受体,采取室内生测的方法,测定了4种苯甲酸型酚酸（对羟基苯甲酸、水杨酸、香草酸、丁香酸）和4种肉桂酸型酚酸（肉桂酸、阿魏酸、对香豆酸、咖啡酸）,以及2种类型混合酚酸对莴苣的化感作用,对其抑制率进行回归分析并计算IC50（半抑制浓度值）.结果表明,单一或混合酚酸浓度高时明显抑制莴苣生长,浓度低时抑制能力减弱或表现促进作用.苯甲酸型混合酚酸对莴苣根长和株高的IC50分别为2.71×10-4和1.56×10-3mol·L-1,而肉桂酸型混合酚酸对莴苣根长和株高的IC50分别为8.01×10-4和1.77×10-3mol·L-1.可见,苯甲酸型酚酸的抑制作用高于肉桂酸型酚酸,且混合酚酸的抑制作用高于单一组分酚酸.

英文摘要：

Bioactivities of 4 benzoic acid derivatives （广hydroxybenzoic acid, salicylic acid, vanillic acid, syringic acid） , 4 cinnamic acid derivatives （cinnamic acid, ferulic acid, jo-coumaric acid, caffeic acid） , as well as their mixtures, were deter^nined in laboratory bioassay with Lactuca sativa L. being the receptor. The regression analysis of inhibitory rates on the growth of lettuce was conducted, and the concentration required to obtain 50% inhibition （IC50） were calculated. The results showed that a single or mixed phenolic acids had significant inhibitory effects on the growths of lettuce at high concentrations, while the inhibitory effect attenuated or became stimulative effects at low concentrations. The IC50 of mixture of benzoic acid derivatives on root length and plant height were 2.71x10 4 and 1.56x10 3 mol ？ L、And the values were 8.01x10 4 and 1.77×10 3 mol· L-1 for mixture of cinnamic acid derivatives. To summa-rize, bioactivities of benzoic acid derivatives on lettuce were higher than those of cinnamic acid derivatives. And bioactivities of the mixture of phenolic acids were higher than those of any single one.