Cry1Ac杀虫蛋白对甜菜夜蛾飞行能力的影响

转Bt基因作物上害虫取食Bt杀虫蛋白后存活并羽化的成虫飞行能力对于其飞离Bt作物，寻找庇护所中敏感个体进行交配、产卵，从而稀释抗性基因频率，实现“高剂量/庇护所”抗性治理策略具有重要意义。本文对取食含不同浓度Cry1Ac杀虫蛋白人工饲料的初羽化（未取食补充营养）甜菜夜蛾飞行能力进行了测试，结果表明，幼虫取食含25、50、100 μg/g和200 μg/g Cry1Ac杀虫蛋白人工饲料存活并羽化的成虫飞行距离、飞行速度和飞行时间均差异显著（p<0.05）。取食含较低浓度Cry1Ac杀虫蛋白（25 μg/g和50 μg/g）的人工饲料有促进成虫飞行的倾向，尽管与取食不含Cry1Ac杀虫蛋白的对照相比，成虫飞行距离、飞行速度和飞行时间均未达到显著增加的水平，但强飞行个体比例明显增加。随着饲料中Cry1Ac杀虫蛋白浓度的升高，羽化的成虫飞行能力显著下降。雄蛾飞行能力下降的程度比雌蛾更加明显。这些数据为转Bt基因作物上迁飞性害虫的种群动态规律及其潜在的抗性治理策略提供了科学依据。

Influences of the insecticidal toxin Cry1Ac on adult flight performance of the beet armyworm,Spodoptera exigua

Variation of the insect adult flight capacity when their larvae fed on Bt insecticidal proteins, is an important index for identifying the individuals successfully escaping from Bt crops to non Bt crops refuge and helping realize “high dose/refuge strategy” through mating with abundant susceptible individuals for managing insect resistance to transgenic crops. The newly emerged adult flight performance indexes, including flight distance, flight velocity and flight duration, were tested when their larvae fed on the artificial diet containing 25, 50, 100 μg/g and 200 μg/g Cry1Ac toxins. Significant difference in adult flight performance was observed after feeding different concentrations of Cry1Ac toxin by larvae. Lower concentrations (25 μg/g and 50 μg/g Cry1Ac toxin) played a positive role in inducing migratory tendency of the species, showing an insignificant increase in flight distance, flight velocity and flight duration. However, the incidence of strong fliers was also higher at 25 μg/g and 50 μg/g. Higher concentrations of Cry1Ac toxin had a significantly negative effect on adult flight, especially female flight. The results provided a basis for evaluating migratory insect population dynamics and managing potential resistance to Bt in transgenic Bt crops.