Abstract: The insect-resistant activity of Bt cotton has significant variation in different tissue and growing period. Bioassay, the method used to determine the insect-resistant activity of Bt cotton to bollworm inside the country, can not determine the expression levels of Bt protein. The ELISA method established by us resolves this problem. Compared with bioassay, ELISA has the merits of spending shorter time, quantifying Bt toxin protein and easy operation. We find that Bt cotton has different Bt toxin protein content in different tissue and growing period using ELISA method. Leaves and flower petals contain more Bt toxin protein than boll and bracteal leaves. In the late growing period, Bt toxin protein content of every tissue decreases significantly.

Key words: Bollworm (Helicoverpa armigera), Bt (Bacillus thuringiensis) cotton, insect-resistant activity, Enzyme-linked immunosorbent assay, bioassay, Bt insecticidal protein

摘要： 转苏云金杆菌(Bacillus thuringensis)杀虫蛋白基因棉花(下称Bt棉)在不同生长期及不同器官上对棉铃虫杀虫活性存在明显差异。目前国内普遍使用生物测试法检测Bt棉对棉铃虫的杀虫活性，但无法定量检测Bt棉中杀虫蛋白的表达量。本实验室建立的酶联免疫学测定方法(ELISA)，可定量检测棉器官内杀虫蛋白的含量。它具有检测周期短，操作简便的优点。用ELISA方法检测Bt棉杀虫蛋白的含量，结果表明，棉叶和花瓣杀虫蛋白含量最高，铃和蕾次之。在棉株生长的后期，各器官杀虫蛋白的含量则有大幅度的下降。

关键词: 棉铃虫, Bt棉, 杀虫活性, ELISA, 生物测试, Bt杀虫蛋白