转基因棉Bt毒蛋白含量与抗棉大卷叶螟效果间的关系分析

棉大卷叶螟Sylepta derogata Fabricius为近年来长江流域棉花中后期的一种重要害虫。在其危害盛期测定了8种转基因棉叶片Bt毒蛋白的含量与受害程度,在此基础上就转基因棉对棉大卷叶螟的抗虫性采用不同抗性指标相结合的方法进行了综合评估,同时对转基因棉对棉大卷叶螟的抗虫效果与毒蛋白含量的相关性进行分析。结果表明:各转基因棉品种的不同部位叶片的毒蛋白含量呈现顶叶最高,功能叶次之,老叶含量最低的趋势。抗蚜8017和SGK321 2个转基因棉品种的棉叶毒蛋白表达量相对较低,平均值在120μg/g以下,对棉大卷叶螟的抗性级别均为中抗。其它供试转基因棉棉叶毒蛋白表达量均值在150μg/g以上,抗性级别也均为高抗,而非转基因棉泗棉3号与石远321对棉大卷叶螟不具抗性。转基因棉对棉大卷叶螟的抗性水平与毒蛋白含量呈正相关。

The relationship between Bt Sylepta derogata in various toxin content and resistance to transgenic Bt cotton varieties

In recent years, Sylepta derogata Fabricius has been an important insect pest of late growth stage cotton in the Yangtze River Region. In order to study the relationship between Bt toxin levels and resistance to S. derogata in transgenic cotton, the Bt toxin content of the leaves of eight Bt cotton varieties was assayed and the resistance of each variety to S. derogata comprehensively evaluated. The results show that the Bt toxin content of the leaves of Kangya-8017 and SGK321 were less than 120 p~g/g and the resistance of these two varieties to S. derogate was moderate. The other 6 varieties of Bt cotton were highly resistant to S. derogate and had toxic protein contents of 〉 150 ~Lg/g. The parental non-transgenic cotton variety did not show any resistance to S. derogate. These results indicate that the resistance of Bt transgenic cotton to S. derogata is related to the level of Bt toxin in the plant.