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用辛硫磷/氟氯氰菊酯(25:1,有效成分)混剂对棉铃虫田间种群(HN)进行33代筛选获得抗性品系(HN-R)。筛选获得的HN-R抗性品系对辛硫磷和氟氯氰菊酯的抗性分别达17.4倍和144.7倍。HN-R品系对两种拟除虫菊酯产生了高水平交互抗性(对氯氰菊酯和氰戊菊酯分别为86.2和23.4倍),对久效磷产生了中等水平交互抗性(5.2倍),对甲基对硫磷(1.6倍)、丙溴磷(1.8倍)和灭多威(2.4倍)产生了低水平交互抗性。酯酶抑制剂DEF能有效抑制HN-R品系对辛硫磷的抗性(增效比为15.3倍),而多功能氧化酶抑制剂PBO则对辛硫磷没有任何增效作用;PBO则使HN-R品系对3种拟除虫菊酯的抗性显著降低(对氟氯氰菊酯、溴氰菊酯和氰戊菊酯的增效比分别为21.9、19.1和21.4倍)。DEF和PBO都能使HN-R对久效磷的抗性下降一半(增效比分别为2.2和2.5倍)。HN-R抗性品系多功能氧化酶活性(以pNA为底物)和酯酶活性(以a-NA为底物)分别为HN品系的6.5倍和1.6倍。因此,在HN-R抗性品系中至少存在2种代谢抗性机理,即增强的酯酶解毒代谢(对辛硫磷、久效磷)和多功能氧化酶介导的氧化解毒代谢(对3种拟除虫菊酯、久效磷)。本研究表明,在田间使用有机磷/拟除虫菊酯混剂可能同时选择出多种代谢抗性机理,从而导致广谱的交互抗性。
A resistant strain (HN-R) was obtained from 33 generations of cotton bollworm (HN) population by using mixture of phoxim / cyfluthrin (25: 1, active ingredient). Resistance to phoxim and cyfluthrin was 17.4-fold and 144.7-fold, respectively, in the HN-R resistant lines screened. The HN-R strain produced high levels of cross-resistance to both pyrethroids (86.2 and 23.4 times for cypermethrin and fenvalerate, respectively) and intermediate levels of monocrotophos (5.2 times) Methyl parathion (1.6-fold), profenofos (1.8-fold) and methomyl (2.4-fold) produced low levels of cross-resistance. Esterase inhibitor DEF could effectively inhibit the resistance of phoxim to HN-R strain (15.3-fold efficiency), whereas PBO, a multifunctional oxidase inhibitor, did not show synergistic effects on phoxim; PBO caused The resistance of the HN-R strain to the three pyrethroids was significantly reduced (21.9, 19.1, and 21.4 fold for cyhalothrin, deltamethrin and fenvalerate, respectively). Both DEF and PBO halved HN-R resistance to monocrotophos (efficiency gains of 2.2 and 2.5 fold, respectively). The multifunctional oxidase activity (with pNA as substrate) and esterase activity (with a-NA as substrate) of HN-R resistant lines were 6.5 and 1.6 times that of HN lines, respectively. Therefore, there are at least two mechanisms of metabolic resistance in the HN-R resistant line, namely enhanced esterase detoxification metabolism (to phoxim, monocrotophos) and multifunctional oxidase-mediated oxidative detoxification metabolism Pyrethroids, monocrotophos). This study shows that the use of organophosphate / pyrethroid combination in the field may simultaneously select a variety of metabolic resistance mechanisms, resulting in broad-spectrum cross-resistance.