转Bt基因抗虫棉对甜菜夜蛾实验种群增长的影响

在室内运用转Bt基因棉国抗22及其亲本对照棉泗棉3号和转Bt CpTI基因棉SGK321及其亲本对照棉石远321的成熟叶片,研究对甜菜夜蛾Spodoptera exigua Hübner种群连续3个世代存活率、繁殖力、种群增长趋势的影响。结果表明:取食两个转基因棉花品种后,对甜菜夜蛾各龄期存活率、繁殖力和种群增长趋势虽有一定影响,但随着取食时间的延长,其影响呈逐步缩小趋势。组建甜菜夜蛾3个连续世代实验种群生命表的结果表明,甜菜夜蛾取食泗棉3号棉花叶片后3个世代的种群趋势指数分别是43.74、135.72和141.17,取食国抗22棉花叶片后的种群趋势指数分别为14.89、82.46和110.24,取食石远321棉花叶片后的种群趋势指数分别是51.63、89.57和128.90,取食SGK321棉花叶片后3个世代的种群趋势指数分别是43.26、81.37和114.66。表明随着取食时间的延长,甜菜夜蛾种群的增长更快,其增长差异在常规棉与转基因棉花间有缩小趋势。

Effect of the transgenic Bt cotton on laboratory population increasing of the beet armyworm Spodoptera exigua Hübner

By feeding Spodoptera exigua Hübner (Lepidoptera:Noctuidae) with the mature leaves of transgenic Bt cotton GK22, transgenic Bt+CpTI cotton SGK321 and their conventional cottons SM3 and Shiyuan321, the influences of different cotton cultivars on the survival rate, fecundity and index of population trend(I)of three continuous generations of the beet armyworm was carried out. Results indicated that the influences of two transgenic cottons were significance on survival rate, fecundity and index of population trend(I), but the influences gradually become lower following the feed time lengthened. The laboratory population life table of the three continuous generations of the beet armyworm showed that the index of population trend (I)of the three generations fed with SM3 was 43.74, 135.72, 141.17 respectively, the I value fed with GK22 was 14.89, 82.46, 110.24 respectively, the I value fed with Shiyuan321 was 51.63, 89.57, 128.90 respectively, and the I value fed with SGK321 was 43.26, 81.37, 114.66 respectively. It indicated that followed by prolonging feed time, population increasing become quicker and quicker, and the increased differences between transgenic cottons and its conventional cottons also become no significant.