【摘要】 实验结果表明，不同抗性水稻品种幼苗接种细条病原菌后，感病品种叶绿素含量的下降速度明显的快于抗病品种。在接菌２～４天，抗病品种病叶的ＳＯＤ、ＰＯＤ、ＣＡＴ活性显著上升，而感病品种ＳＯＤ和ＣＡＴ活性明显下降；ＰＯＤ活性虽有所上升，但其上升速度慢于抗病品种。相关分析表明，抗病品种病叶ＳＯＤ酶活性的变化量与ＣＡＴ和ＰＯＤ的变化量呈显著正相关，而感病品种呈微弱正相关。因而推测幼苗叶片中各种保护性酶失去原来的平衡很可能是感病品种易于感病的一个生理原因。更多还原

【Abstract】 The experimental results showed that after rice seedlings were infected by Xanthomonas Campestris pv. Oryzicola, the decrease rate of chlorophyll content in infected leaves of resistant varieties was lower than that of susceptible varieties. During the period from the 2nd to 4th day after inoculation with the pathogen, the activity of Superoxide Disrnutase(SOD).Peroxidase(POD)and Catalase(CAT) in infected leaves of resistant varieties increased significantly,while the activity of susceptible va-rieties SOD and POD decreased,Although the POD activity of susceptible varieties increased,the in-crease rate of that was lower than that of resistant varieties, There was significantly positive relation be-tween the change of SOD activity and the change of POD and CAT activity in resistant varieties,where as susceptible varieties only displayed weak positive relation between therm.So it is suggested that violat-ing original balance among SOD, POD and CAT activity may be a physiological reason that makes sus-ceptible varieties susceptible to the pathogens,更多还原