昆虫学报2012，Vol.55Issue(10)：1154-1160,7.
Cry1Fa对Cry1Ac抗性棉铃虫的毒力评价
Evaluation of the toxicity of Cry1Fa to the Cry1Ac-resistant cotton bollworm,Helicoverpa armigera(Lepidoptera:Noctuidae)
摘要
Abstract
Cry 1 Fa-expressing corn and cotton have been commercially planted in U. S in order to effectively control several Lepidoptera pests. Making clear the cross-resistance of cotton bollworms (Helicoverpa armigera) to CrylAc and Cry 1 Fa and the synergism between the two toxins could provide the theoretical bases for rationally applying CrylFa + CrylAc cotton. The toxicity of CrylFa to the susceptible strain (96S) and the resistant strain (BtR, selected by CrylAc, the resistance ratio was 2 194. 15-fold) was tested in our study. The results showed that the toxicity of CrylFa was lower than CrylAc to 96S, the LC50 value of CrylFa was 504. 80 times as high as that of CrylAc, and there was 19.98-fold cross-resistance to CrylFa in the CrylAc-resistant strain (BtR). CrylFa mixed with CrylAc could increase the toxicity of CrylFa against 96S, and especially when the concentration of CrylFa was low, the synergistic effect was significant. However, the toxicity of CrylAc could be improved just when being added with high-dose CrylFa. Because the BtR strain had resistance to CrylAc, the toxicity of CrylAc to BtR reduced obviously. Mixing CrylFa into high-dose CrylAc could increase the mortality of BtR (P -0. 0015 , F = 6. 88, df-6), but the highest mortality was only 58. 33% . The results of the 2-D-optimum orthogonal design experiment showed that CrylAc had significant effect to control the susceptible cotton bollworm (t, = 13. 76 > t0.05) , and the influence of interactive effect between CrylAc and CrylFa on toxicity was also significant (t22 =2.42 > t0.05; t11=6.95 >t0.05; t12=3.43 > t0.05). CrylAc and CrylFa had significant effect against the resistant cotton bollworm (t, =3.03 > t0.05; t2 = 2. 59 > t0.05) , but CrylAc was the key determinant for the mortality of the susceptible and resistant cotton bollworms. The optimum concentration ranges of CrylAc and CrylFa were 1. 41 - 2. 10 (jig/cm . However, the interactive effect between CrylAc and CrylFa was not significant in the BtR resistant strain. Thus, although the crops expressing CrylF +CrylA can expand the spectrum of killing insects, however, because of the cross-resistance and the undesirable effect in managing the CrylAc-resistant bollworm, transgenic CrylF + CrylA cotton is not recommended for planting in China.关键词
棉铃虫/Cry1Ac/Cry1Fa/毒力/交互抗性/协同作用Key words
Helicoverpa armigera/ CrylAc/ CrylFa/ toxicity/ cross resistance/ synergism分类
生物科学引用本文复制引用
魏纪珍,郭予元,高希武,张涛,梁革梅..Cry1Fa对Cry1Ac抗性棉铃虫的毒力评价[J].昆虫学报,2012,55(10):1154-1160,7.基金项目
国家转基因生物新品种培育重大专项课题(2011ZX08011-002) （2011ZX08011-002）
