双价基因(Bt+CpTI)抗虫棉对棉铃虫的杀虫活性及抑制生长作用

Control Efficacy of Transgenic Cotton Expressing Bt & CpTI Genes to Helicoverpa armigera

比较了转 Bt+ Cp TI双价基因抗虫棉 (双价棉 )与转 Bt单基因棉 ( Bt棉 )对棉铃虫不同Cry1 Ac抗性种群杀虫活性的时间动态和对不同龄期幼虫的抑制生长作用。结果表明 ,双价棉叶对棉铃虫的杀虫活性于 6月底最高 ,7月底和 8月下旬逐渐下降 ,高于同期测定的 Bt棉的杀虫活性。双价棉对棉铃虫抗性种群 2～ 5龄幼虫的死亡率、存活幼虫体重、化蛹率和成虫羽化率等生长发育的影响 ,均显著高于 Bt棉。用 Bt棉叶连续饲养不同龄期抗性棉铃虫 ,2龄幼虫就可部分化蛹和羽化 ,而用双价棉饲养 ,5龄以下幼虫不能化蛹和羽化 ,表明双价棉对抗性棉铃虫具有较强的抗虫性。

The inhibition and insecticidal activity of transgenic cotton expressing both modified Cry1A gene from Bacillus thuringiensis (Bt) and cowpea trypsin inhibitor (CpTI) insecticidal protein gene were evaluated using Cry1Ac resistant and the homologous susceptible populations of Helicoverpa armigera Hübner. Insecticidal activity of the transgenic two genes cotton was significantly higher than that of the transgenic cotton expressing one modified Bt gene, and the highest one was observed at late June among the growth season. Mortality of larvae from 2nd to 5th instar was significantly higher, and the weight of survival larvae, pupation rate and eclosion rate were significantly lower fed on transgenic two genes cotton compared with that fed on transgenic Bt gene cotton. The 2nd instar larvae of the resistant population successively fed on one gene cotton leaf can partly developed to pupae stage and partly eclosion, but larvae of the same population successively fed on two genes cotton leaf can't survive to pupae stage until the 5th instar. The results showed that transgenic cotton expressing pyramiding insecticidal protein genes has higher resistance to Cry1Ac resistant population of H.armigera.