复合性状转基因棉花杀虫蛋白表达量及对4种鳞翅目害虫的抗性

The Effectiveness of Genetically Modified Stacked Cotton against Four Species of Lepidoptera and Expression Analysis of Bt Proteins

为了探讨复合性状棉花在长江流域对主要鳞翅目害虫的影响,本文以转Cryl Ac＋Cry2Ab2＋Cp4-epsps棉花Daiza24为材料,对其外源杀虫蛋白的时空表达及对棉铃虫、红铃虫、斜纹夜蛾、甜菜夜蛾4种主要鳞翅目害虫的抗性进行了测定.结果表明：CrylAc杀虫蛋白在复合性状棉花Daiza24和单价抗虫棉TaiD-5的各生育期不同组织器官中均能相对稳定地高表达,除铃期叶片外2个品种无显著差异.Daiza24各生育期不同组织器官中的Cry2Ab2杀虫蛋白含量高于Cry1 Ac蛋白.同时,随着棉花逐渐生长,两种杀虫蛋白在棉花繁殖器官中的含量出现逐步下降的现象.室内生物测定和田间调查结果表明,在2、3、4代棉铃虫发生盛期,Daiza24不仅对棉铃虫、红铃虫有较好的控制效果,而且对斜纹夜蛾和甜菜夜蛾等非靶标害虫也有较好的控制作用,其室内杀虫效果分别为74.81％～81.81％、76.14％～85.14％,显著高于当地主栽抗虫棉品种TaiD-5,这与其杀虫蛋白表达量基本一致.

To evaluate the effectiveness of genetically modified stacked cotton against Lepidoptera pests in the Yangtze River valley of China, the Bt insecticidal protein content of transgenie cotton Daiza24 with triple genes （CrylAc＋Cry2Ab2＋Cp4-epsps） was analyzed using ELISA, and the efficacy of resistance to four Lepidoptera pests （Heliothis armigera, Pectihcphora gossypiella, Spodoptera litura, and S. exigua） were described under laboratory and field conditions. The results showed that Cryl Ae protein could be expressed relatively stably in different tissues and organs of Daiza24 and TaiD-5 at each growth stage, with no significant differences except in leaves at the bolling stage. Compared with CrylAc, Cry2Ab2 protein content was relatively high in all tissues of Daiza24 at all growth stages and the level of CrylAe and Cry2Ab2 proteins in the reproductive organs （squares, flowers, and bolls） decreased as the season progressed. Daiza24 seemed to have greater effects against not only H. armigera and P. gossypiella, but also against S. litura and S. exigua. The mean mortalities of S. litura and S. exigua on Daiza24 ranged from 74.81%-81.81% and 76.14%-85.14%, respectively, and were significantly higher than those on TaiD-5. The larval mortality rates in the laboratory bioassay and with field monitoring were consistent with the Bt protein level at different developmental periods and in different organs.