在转Bt基因棉压力下棉铃虫和异色瓢虫的波动性不对称

以取食转Bt基因棉的棉铃虫和取食转Bt基因棉上的蚜虫的异色瓢虫为研究对象，结合各自的适合度参数考察了波动性不对称（fluctuating asymmetry, FA）在不同种群中各对称性状间的表现情况。结果表明： 处理组棉铃虫种群的前、中、后足腿节，前翅肘横脉，前翅副室短径，后翅翅长均表现出FA；与对照种群比较，前足腿节与后翅翅长的FA值较高。 适合度参数测定结果显示，棉铃虫卵孵化率与成虫寿命显著低于对照种群，而成虫产卵量和幼虫发育历期与对照种群差异不显著。异色瓢虫取食了转Bt基因棉上的蚜虫后对其适合度各参数及各虫龄的捕食功能反应均无不良影响，其后翅翅长表现出FA，但与对照种群的FA值无显著差异。FA的大小与种群适合度间存在一定的联系，尚需做进一步的分析。

Fluctuating asymmetry in Helicoverpa armigera (Hübner) and Harmonia axyridis (Pallas) under the stress of Bt-transgenic cotton

The fluctuating asymmetry (FA) in response to the stress of Bt-transgenic cotton was estimated among the different symmetric characters in the cotton bollworm (Helicoverpa armigera, CB) and the Asian lady beetle (Harmonia axyridis, ALB) populations in the laboratory. The CB was reared on transgenic Bt cotton and the ALB was reared on aphids (Aphis gossypii) feeding on transgenic Bt cotton. The results indicated that FA was found in fore femur, mid femur, hind femur, two vein sections L1 and L2 in fore wing and hind wing of the CB. The values of FA of fore femur and hind wing were higher than those of the control population. Egg hatchability and adult longevity of the CB were significantly lower than those of the control population. The fitness and predatory function of the ALB were not affected by feeding on aphids on transgenic Bt cotton. FA in hind wing of the ALB was not significantly different with the control population. The investigation showed some positive relationship between FA and fitness of CB and ALB, but more studies will be needed to establish the correlation between FA and fitness of these species. The possibility using FA as a sensitive indicator of the ecological risk of genetically modified crops was discussed.