Fitness costs of reproductive capacity and ovarian development in a Bt-resistant strain of the cotton bollworm Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae)

作者:Zhang, WN (Zhang, Wanna)^[ 1 ] ; Ma, L (Ma, Long)^[ 2 ] ; Zhong, F (Zhong, Feng)^[ 1 ] ; Wang, YN (Wang, Yanan)^[ 1 ] ; Guo, YY (Guo, Yuyuan)^[ 1 ] ; Lu, YH (Lu, Yanhui)^[ 1 ] ; Liang, GM (Liang, Gemei)^[ 1 ]

PEST MANAGEMENT SCIENCE

卷: 71

期: 6

页: 870-877

特刊: SI

DOI: 10.1002/ps.3900

出版年: JUN 2015

摘要

BACKGROUNDThe cotton bollworm Helicoverpa armigera has developed resistance to the insecticidal Cry1Ac toxins produced by Bacillus thuringiensis (Bt) in China. To gain a better understanding of the fitness cost associated with resistance evolution, reproductive capacities and ovarian development were examined in four strains of H. armigera: a Cry1Ac-susceptible strain (96S); a Cry1Ac-resistant strain fed on an artificial diet with Cry1Ac toxin for 135 generations (BtR); two strains derived from BtR: a strain grown without Cry1Ac selection for 38 generations (CK1) and a strain grown for one generation without Cry1Ac selection (CK2). 

RESULTSStrains 96S and CK1 had similar reproductive capacity and Cry1Ac susceptibility. Compared with the 96S and CK1 strains, the fecundity and hatching rate of CK2 were respectively more than 30% and 50% lower. Moreover, the number of eggs laid by BtR was significantly lower than the number of eggs laid by 96S and CK1, but higher than the number of eggs laid by CK2. In accordance with the differences in reproductive capacity, ovarian development in CK2 and BtR was significantly delayed. 

CONCLUSIONThese results indicated that there was a fitness cost in the reproductive physiology in the resistant strains. Reversion to susceptibility to the Bt Cry-toxin in the resistant CK1 strain was associated with an increase in reproductive capacity. (c) 2014 Society of Chemical Industry

关键词

作者关键词:Bacillus thuringiensis (Bt); fitness cost; Helicoverpa armigera; reproductive physiology; resistance

KeyWords Plus:BACILLUS-THURINGIENSIS; PLUTELLA-XYLOSTELLA; INSECT RESISTANCE; TRANSGENIC COTTON; RELATIVE FITNESS; PINK-BOLLWORM; CRY1AC; TOXIN; CROPS; CRY1AC-RESISTANT