采用室内喂虫和田间接卵两种方法对4个玉米回交二代转基因材料进行了抗虫性鉴定。结果表明 ,不同转基因材料的抗虫性不同 ;同一材料的不同单株间的抗虫性各异 ,有的表现高抗性 ,有的几乎没有抗性 ;正反双向回交的结果 ,其抗虫性存在显著差异 ,外源Bt基因通过雌配子的传递率显著高于通过雄配子的传递率。因此 ,以抗虫株作母本进行正向回交是较为有效的回交方法 Insecticidal identification of 4 maize backcross second generation transgenic materials was conducted by indoor feeding and field cupping. The results showed that the resistance of different transgenic materials was different. Insect resistance was different among different plants of the same material, while others showed high resistance and almost no resistance. The results of forward and backward two-way backcrossing, There was a significant difference in pest sex. The transmissibility rate of exogenous Bt gene by female gametes was significantly higher than that by male gametes. Therefore, the use of insect-resistant plants as the parent backcross is more effective backcrossing method