转Bt+ CpTI双价抗虫棉的遗传稳定性及生育后期对棉铃虫抗性表现

Genetic Stability of Transgenic Bt+CpTI Cotton and Its Resistance to Helicoverpa armigera in Later Developmental Stage

本文研究了转 Bt+Cp TI双价抗虫棉双抗 - 14个世代的棉铃虫抗性及其生育后期棉花对棉铃虫的杀虫活力。研究结果表明 4个不同世代的双抗 - 1在苗期、蕾期、开花期和铃期的抗虫性水平相近 ,说明双抗 - 1的棉铃虫抗性能稳定遗传 ;双抗 - 1不同部位叶片抗虫性明显 ,抗性水平与中心 Bt相近 ,也表现出前期抗虫性强后期抗虫性弱的时空表达特性。尽管抗虫性有所下降 ,双抗 - 1在生育后期仍能延缓棉铃虫 1～ 3龄幼虫的生长发育使其不能化蛹羽化并逐渐死亡 ,而在对照苏棉 12号上的 1～ 3龄幼虫能化蛹羽化。田间种植试验也表明双抗 - 1生育后期没有被棉铃虫危害的症状 ,表现出了高抗虫性。

The genetic stability of transgenic Bt+CpTI insect resistant cotton(named Shuang-1) in four generations and its resistance to Helicoverpa armigera especially in later developmental stage were presented in the present paper. Laboratory bioassay Showed there was no significant difference in the resistance level of Shuang-1 in four generations at seedling, budding, flowering and boll setting stages, which indicated that the resistance is genetically stable. However, temporal fluctuation existed for the transgenic Bt+CpTI line just like transgenic Bt lines, i.e., resistance declining with cotton development. The 1 st , 2 nd and 3 rd instar larvae all developed slowly, could not pupated, emerged and died finally when they were fed with the leaves of Shuang 1 in later developmental stage, while they could normally pupated and emerged with the ones of Sumian 12 at the same stage. The field investigation also showed significant resistance to bollworms since the buds, flowers and bolls in Shuang 1 during later developmental stage were not damaged.