转Cry1Ac/1Ab基因棉花对棉铃虫的控制效果及对甜菜夜蛾和斜纹夜蛾生长发育的影响
The effects of transgenic Cry1Ac/1Ab cotton on cotton bollworm control and growth and development of non-target pests

为评估转Cry1Ac/1Ab基因棉花对棉铃虫Helicoverpa armigera的抗性及对非靶标害虫甜菜夜蛾Spodoptera exigua和斜纹夜蛾S.litura生长发育的影响，采用室内生测法测定其对棉铃虫的抗性及对甜菜夜蛾和斜纹夜蛾不同龄期幼虫存活率、营养代谢及中肠酶活性的影响。结果表明，转Cry1Ac/1Ab基因棉花对棉铃虫第2代幼虫的抗性程度最高，幼虫校正死亡率达91.33%，但对甜菜夜蛾和斜纹夜蛾的抗性程度较低，幼虫校正死亡率分别为15.33%和13.33%。甜菜夜蛾和斜纹夜蛾各龄期幼虫取食转Cry1Ac/1Ab基因棉花后，其存活率与取食常规棉花对照显著差异；甜菜夜蛾对转Cry1Ac/1Ab基因棉花叶片的相对取食量、近似消化率分别为16.68和93.12%，均高于取食常规棉花对照的10.72和92.00%，但差异不显著，而斜纹夜蛾取食转Cry1Ac/1Ab基因棉花后的各项营养指标均低于取食常规棉花对照，差异也不显著。取食转Cry1Ac/1Ab基因棉花后，甜菜夜蛾的过氧化物酶活性为0.02 U/mg prot，显著低于取食常规棉花的0.05 U/mg prot；斜纹夜蛾的酸性磷酸酶活性为0.15 U/mg prot，高于取食常规棉花的0.10 U/mg prot，但差异不显著，其它中肠酶活性均低于对照，亦显著差异。
To assess the resistance of transgenic cotton to cotton bollworm Helicoverpa armigera (Hübner) and its effect on growth and development of Spodoptera exigua and S. litura, the larval survival rate, nutrition and energy metabolism levels and the midgut enzyme activity were tested with laboratory bioassay methods. The corrected mortality of bollworms reared on transgenic Cry1Ac/1Ab cotton peaked at 91.33% in 2nd generation bollworms, indicating that this variety had high resistance to the 2nd generation cotton bollworm. However, its resistance to S. exigua and S. litura was low, in which the corrected larval mortalities of these two pests fed on transgenic Cry1Ac/1Ab cotton were 15.33% and 13.33%, respectively. The survival rates of S. exigua and S. litura larvae in different developmental stages fed on transgenic cotton were not significantly different from that on the conventional cotton. The relative feeding rate and approximate digestion rate of S. exigua fed on transgenic cotton were 16.68 and 93.12%, higher than that on the conventional cotton (10.72 and 92.00%), but not statistically significant. The nutrition index of S. litura was lower than that fed on conventional cotton, but the results were not statistically significant. When fed with transgenic Cry1Ac/1Ab cotton, the peroxidase activity of S. exigua was 0.02 U/mg prot, significantly lower than that when fed on conventional cotton (0.05 U/mg prot), and the acid phosphatase activity of S. litura was only 0.15 U/mg prot, higher than that when fed on conventional cotton (0.10 U/mg prot), but the activities of other midgut enzymes were not significantly different from the control.