Bt蛋白对杨扇舟蛾连续世代存活与发育的影响

Effects of Bacillus thuringiensis Proteins on the Survival and Development of Successive Generations of Clostera anachoreta

旨在探讨杨扇舟蛾(Clostera anachoreta)在BtCry1Ac杀虫蛋白处理后耐药性的产生及形成规律。以转基因‘741’杨高抗品系‘Pb29’叶片及浸泡不同梯度Cry1Ac杀虫蛋白原毒素的‘741’杨树叶片对杨扇舟蛾存活和生长发育进行室内生测,分析3代幼虫存活与发育趋势。结果表明:(1)高质量浓度Bt对低龄幼虫有着较强的毒杀作用,且致死效果随着代数延长没有明显减弱;幼虫对低质量浓度Bt及转基因Pb29杨耐受性提高,死亡速度减慢,校正死亡率降低。(2)幼虫取食Bt叶片后发育受到抑制,第1代和第2代历期较对照组明显延长,停止胁迫后对老龄幼虫龄期影响不明显。(3)Bt能显著降低蛹质量,但随着代数延长而逐渐回升,且亚致死剂量增幅最高。随着杨扇舟蛾的世代延续,Cry1Ac蛋白对其致死效果和抑制发育能力逐渐降低,存在杨扇舟蛾世代种群对转Bt植物耐受性累积发展的风险。

To investigate the emergence and formation of drug resistance of C.anachoreta after BtCry1Ac insecticidal protein treatment,and to provide a basis for the effective and sustainable utilization of Bt and the solution of insect resistance to Bt.The survival and development of the three generation larvae of C.anachoreta were studied by using leaves of transgenic‘741’poplar high resistant strains‘Pb29’and‘741’poplar leaves soaked with different concentrations of Cry1Ac insecticidal toxin.The results showed that:(1)High concentration of Bt had a strong toxic effect on young larvae,and the lethal effect did not decrease significantly with the prolongation of algebra.The tolerance of larvae to low concentration of Bt and transgenic‘Pb29’poplar increased,the death rate slowed down,and the corrected mortality rate decreased.(2)The development of larvae was inhibited after feeding on Bt leaves,and the duration of the first and second generations was significantly longer than that of the control group.(3)Bt could significantly reduce the pupa mass,but gradually increased with the prolongation of algebra,and the increase of sub lethal dose was the highest.With the continuation of the generations of the C.anachoreta larvae,the Cry1Ac protein gradually reduced its lethal effect and inhibited development ability,and there is a risk of accumulative development of the population tolerance to Bt transgenic plants.