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亚洲玉米螟Ostrinia furnacalis(Guenée)是危害玉米的重要害虫之一,转Bt基因抗虫玉米为其防治提供了新的途径。然而,靶标害虫产生抗性将严重阻碍Bt制剂及转Bt基因抗虫玉米的持续应用。明确害虫对转Bt基因玉米表达的毒素蛋白的抗性演化,对于制定科学有效的抗性治理策略具有重要的理论和实际意义。本实验通过人工饲料汰选法研究了Bt Cry1Ie毒素胁迫下亚洲玉米螟的抗性发展及汰选14代的种群对其他Bt毒素(Cry1Ab,Cry1Ac和Cry1Fa)的交互抗性,并观察了Cry1Ie蛋白胁迫对亚洲玉米螟生物学的影响。结果表明:随着汰选压不断提高,亚洲玉米螟种群对Cry1Ie毒素的敏感性逐渐下降。汰选14代后,种群对Cry1Ie毒素的抗性水平提高了23倍。然而,Cry1Ab,Cry1Ac和Cry1Fa对所获Cry1Ie汰选种群的毒力与对敏感种群的毒力相比没有显著差异,说明Cry1Ie汰选没有引起亚洲玉米螟对Cry1Ab,Cry1Ac和Cry1Fa毒素产生交互抗性。同时,与敏感种群相比,Cry1Ie汰选14代的种群幼虫平均发育历期延长5.7 d,蛹重减轻13.7%,单雌产卵量下降40.0%。本研究结果说明,大面积单一种植转cry1Ie基因抗虫玉米,可能引起亚洲玉米螟产生抗性;亚洲玉米螟Cry1Ie抗性种群对Cry1Ab,Cry1Ac和Cry1Fa没有交互抗性,含有cry1Ie和cry1Ab,cry1Ac或cry1F双/多基因抗虫玉米,可作为靶标害虫抗性治理的重要策略。
Ostrinia furnacalis (Guenée) is one of the most important pests that endanger maize. Transgenic Bt insect-resistant maize provides a new way for its control. However, the resistance of target pests severely hinders the continuous application of Bt formulation and Bt transgenic insect resistant maize. It is of great theoretical and practical significance to clarify the evolution of the resistance of pests to the toxin protein expressed by Bt corn and to develop a scientifically effective resistance management strategy. In the present study, the resistance development of the Asian corn borer (Bombyx mandarinoides) to Bt Cry1It toxin and the cross-resistance of 14 generations to other Bt toxins (Cry1Ab, Cry1Ac and Cry1Fa) Effects of stress on the biology of the Asian corn borer. The results showed that the susceptibility of Asiatic corn borer to Cry1Ie toxin decreased gradually with the increasing selection pressure. After 14 generations of selection, the population’s resistance to Cry1Ie toxin increased 23-fold. However, the virulence of Cry1Ab, Cry1Ac and Cry1Fa on the Cry1Ie eliminated population was not significantly different from that on the susceptible population, indicating that Cry1Ie elimination did not cause cross-resistance to Aspergillus intermedia on Cry1Ab, Cry1Ac and Cry1Fa toxins . At the same time, compared with the susceptible population, the larval larval population of Cry1Ie for 14 generations was prolonged by 5.7 days, the pupal weight was reduced by 13.7%, and the number of eggs laid per female was decreased by 40.0%. The results of this study indicate that large-scale monoculture of insect-resistant corn with cry1Ie gene may cause resistance to the Asian corn borer. The Asian corn borer Cry1Ie-resistant population has no cross resistance to Cry1Ab, Cry1Ac and Cry1Fa, and contains cry1Ie and cry1Ab, cry1Ac or cry1F double / multi-gene insect-resistant corn can be used as an important strategy for target pest resistance management.