转Bt基因南林895杨对美国白蛾抗虫性研究

Study on the insect resistance of Bt transgenic poplar Nanlin 895 to Hyphantria cunea

【目的】通过对转Bt基因南林895杨进行虫试测定,分析转基因植物对不同世代美国白蛾Hyphantria cunea的杀虫活性、转基因杨树抗虫效果的时空动态、转基因杨树对不同龄期美国白蛾的杀虫效果,以及对美国白蛾幼虫生长发育的影响,为转基因杨树的应用推广和美国白蛾防治提供相关依据。【方法】以实验室获得的转Bt(Cry1Ah1)基因南林895杨16个株系为材料,对美国白蛾幼虫进行室内喂养和田间套笼饲虫实验,实验分别采用不同世代、不同虫龄的美国白蛾幼虫为实验对象,测量其死亡率、化蛹率及取食量等指标,分析转Bt基因杨树对于美国白蛾生长的实际影响,并选取不同部位叶片分析杀虫效果的空间变化。【结果】16个转Bt基因南林895杨株系中,A-4-6、A-5-0、A-5-23和X-2-7株系具有良好的杀虫效果,幼虫取食叶片12 d后的校正死亡率为37.5%~68.9%。A-4-6株系的毒蛋白表达量最高达到11500.01 ng/g,占总蛋白表达量的0.0478%。其余5个杀虫活性较好株系的毒蛋白表达量均大于4669.38 ng/g,除Z-1-3株系,各株系毒蛋白量占总蛋白量均超过0.02%。抗虫效果明显的株系上部叶片的抗虫效果优于中部叶片,下部叶片的抗虫效果差。不同虫龄比对结果表明低龄幼虫的校正死亡率显著高于高龄幼虫(P<0.05),而化蛹率随着龄期的升高而升高,幼虫对杀虫性的敏感度随着龄期的升高逐渐下降。【结论】转基因南林895杨中Bt基因的表达能够有效的抑制美国白蛾的生长,并具有时空特异性,其中A-4-6、A-5-0及A-5-23三个株系具有良好的杀虫效果,适用于作为抗虫杨树树种进行推广。

【Objective】The insecticidal activity of transgenic plants on Hyphantria cunea of different generations,the temporal and spatial dynamics of insect resistance of transgenic poplar,the insecticidal effect of transgenic poplar on different instars of Hyphantria cunea,and the effect of transgenic poplar on the growth and development of Hyphantria cunea larvae were analyzed by insect test of transgenic poplar Nanlin 895.This study provided the basis for the application and popularization of transgenic poplar and the control of Hyphantria cunea.【Method】16 strains of transgenic Bt(Cry1Ah1)poplar Nanlin 895 were used as materials to feed the American white moth larvae in the laboratory and in the field.The mortality,pupation rate and food intake of white moth larvae of different generations and different instars were measured,and the leaves of different parts were selected.The spatial variation of insecticidal effect was analyzed.【Result】Among the 16 Bt transgenic poplar Nanlin 895 lines,A-4-6,A-5-0,A-5-23 and X-2-7 had good insecticidal effects.The corrected mortality of larvae after feeding on leaves for 12 days was 37.5%-68.9%.A-4-6 strain got the highest expression of toxic protein to reach 11500.01 ng/g,accounting for 0.0478%of total protein expression.The expression of virulent proteins in the other 5 strains with good insecticidal activity was higher than 4669.38 ng/g.Except for Z-1-3 strains,the virulent proteins in each strain accounted for more than 0.02%of the total protein.The insect-resistant effect of upper leaves was better than that of middle leaves,while the insect-resistant effect of lower leaves was worse.The corrected mortality of young larvae was significantly higher than that of older larvae(P<0.05).Comparing the pupation rate of different instar larvae,it was found that the pupation rate increased with the increase of instar,and the sensitivity of larvae to insecticide decreased with the increase of instar.【Conclusion】The expression of Bt gene in transgenic Nanlin 895 poplar could effectively inhibit the growth of Hyphantria cunea with spatial specificity.The three strains A-4-6,A-5-0 and A-5-23 have good insecticidal effects and are suitable for popularization as insect-resistant poplar species.