转双价基因棉(Bt+CpTI)对七星瓢虫捕食棉蚜功能反应的影响

Effects of Transgenic Bt Plus CpTI Cotton on Predating Function Response of Coccinella septempunctata to Aphis gossypii Glover

室内用生物测定方法评价了七星瓢虫的5个虫态对取食转(Bt+CpTI)双价基因棉(SGK321)和常规棉(石远321)棉蚜在不同密度下捕食功能的影响。结果表明,捕食功能反应符合Holling-Ⅱ方程模型。由模型得出在一定范围内捕食量随猎物密度的增大而增大;其寻找效应均随棉蚜密度的增加而降低。捕食量除在成虫期N=80,240和二龄期N=80 3个密度差异显著小于常规棉外,其他密度都与常规棉无显著差异。与常规棉相比,1、3龄和成虫期的瓢虫对转基因棉上生长的蚜虫控制能力和最大捕食量要强于常规棉。就试验总体评价,转双价基因棉(Bt+CpTI)处理的棉蚜对七星瓢虫总体的捕食功能反应影响不大。

The predating functional response of Coccinella septempunctata with 5 different stages were studied by feeding on the cotton aphids, which were respectively reared on the transgenic （Bt ＋ CpTI） cottons（ SGK321 ） and its parental variety （Shiyuan321） using the biological assay in laboratory condition. The results indicated that the predating functional response matched Holling type Ⅱ mode. The predating number increased with the prey density, while the searching efficiency decreased with the the prey density. The predating numbers in 80 and 240 in adult and 80 in 2nd instar larvae showed significantly lower than the control cotton while others did not differ significantly to the control cotton. It indicated that the maximum of predating number of the 1st and 3rd instar larvae and adult was higher when compared with control cotton and the controlling of the cotton aphids was stronger than the control cotton. In conclusion, the transgenic Bt plus CpTI cotton appeared little effect on predating function response of CoccineUa septempunctata to Aphis gossypii Glover.