Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangzhou 510640, China.
Toxins (Basel). 2021 Mar 22;13(3):227. doi: 10.3390/toxins13030227.
Concerns about resistance development to conventional insecticides in diamondback moth (DBM) (L.) the most destructive pest of vegetables, have stimulated interest in alternative pest management strategies. The toxicity of subsp. (Bt GO33A) combined with chlorantraniliprole (Chl) has not been documented. Here, we examined single and combined toxicity of chlorantraniliprole and Bt to assess the levels of resistance in four DBM strains. Additionally, enzyme activities were tested in field-original highly resistant (FOH-DBM), Bt-resistant (Bt-DBM), chlorantraniliprole-resistant (CL-DBM), and Bt + chlorantraniliprole-resistant (BtC-DBM) strains. The Bt product had the highest toxicity to all four DBM strains followed by the mixture of insecticides (Bt + Chl) and chlorantraniliprole. Synergism between Bt and chlorantraniliprole was observed; the combination of Bt + (Bt + Chl) (1:1, LC:LC) was the most toxic, showing a synergistic effect against all four DBM strains with a poison ratio of 1.35, 1.29, 1.27, and 1.25. Glutathione -transferase (GST) and carboxyl-esterase (CarE) activities showed positive correlations with chlorantraniliprole resistance, but no correlation was observed with resistance to Bt and Bt + Chl insecticides. Expression of genes coding for PxGST, CarE, AChE, and MFO using qRT-PCR showed that the PxGST and MFO were significantly overexpressed in Bt-DBM. However, AChE and CarE showed no difference in the four DBM strains. Mixtures of Bt with chlorantraniliprole exhibited synergistic effects and may aid the design of new combinations of pesticides to delay resistance in DBM strains substantially.
对小菜蛾（DBM）（L.）这种最具破坏性的蔬菜害虫对传统杀虫剂产生抗药性的担忧，刺激了人们对替代害虫管理策略的兴趣。尚未有文献记录亚种（Bt GO33A）与氯虫苯甲酰胺（Chl）联合使用的毒性。在这里，我们检测了氯虫苯甲酰胺和 Bt 的单一和联合毒性，以评估四种 DBM 品系的抗药性水平。此外，还在田间原始高度抗性（FOH-DBM）、Bt 抗性（Bt-DBM）、氯虫苯甲酰胺抗性（CL-DBM）和 Bt + 氯虫苯甲酰胺抗性（BtC-DBM）品系中测试了酶活性。Bt 产品对所有四种 DBM 品系的毒性最高，其次是杀虫剂混合物（Bt + Chl）和氯虫苯甲酰胺。Bt 和氯虫苯甲酰胺之间观察到协同作用；Bt +（Bt + Chl）（1:1，LC:LC）的组合毒性最高，对所有四种 DBM 品系均表现出协同作用，其毒力比为 1.35、1.29、1.27 和 1.25。谷胱甘肽-S-转移酶（GST）和羧酸酯酶（CarE）活性与氯虫苯甲酰胺抗性呈正相关，但与 Bt 和 Bt + Chl 杀虫剂抗性无关。使用 qRT-PCR 检测编码 PxGST、CarE、AChE 和 MFO 的基因的表达表明，Bt-DBM 中 PxGST 和 MFO 显著过表达。然而，在四种 DBM 品系中，AChE 和 CarE 没有差异。Bt 与氯虫苯甲酰胺的混合物表现出协同作用，可能有助于设计新的杀虫剂组合，以大大延缓 DBM 品系的抗药性。
