maydis race CI and HMCI torin have been determineel; (3)The mortality rate of root cap cell may act as an indicator to detect the activity of HMCI toxin and the rind of new male sterile cytoplasms.

• （3）HMCI毒素对玉米根冠细胞致死率可以作为鉴定毒素活性强弱和鉴别新玉米雄性不育胞质类别的病理指标