以莴苣为试材,研究了二苯胺对莴苣的化感作用及其作用机理.结果表明,不同浓度的二苯胺对莴苣种子发芽和幼苗生长均有不同程度的抑制作用,并随浓度的增加,其抑制作用增大,当浓度达到5×10-4mol/L,莴苣种子完全被抑制;不同浓度的二苯胺影响莴苣体内SOD、POD、CAT和Ca2+-ATPase的活性,当浓度增加到一定的值时,SOD、POD、CAT和Ca2+-ATPase的活性逐渐降低,致使细胞膜质过氧化作用增强,细胞膜受到伤害,MDA含量增加. The lettuce was used as material to study the allelopathy and its mechanism of diphenylamine on lettuce.The results showed that different concentrations of diphenylamine inhibited the seed germination and seedling growth of lettuce in different degrees and with increasing concentration, The inhibitory effect was increased when the concentration of 5 × 10-4mol / L, lettuce seed was completely inhibited; different concentrations of diphenylamine lettuce SOD, POD, CAT and Ca2 + -ATPase activity, when the concentration increased to a certain value , The activities of SOD, POD, CAT and Ca2 + -ATPase decreased gradually, which resulted in the enhancement of membrane peroxidation, the damage of cell membrane and the increase of MDA content.