小菜蛾抗性个体不敏感乙酰胆碱酯酶的鉴定

TECHNIQUE FOR IDENTIFICATION OF INSENSITIVE ACETYLCHOLINESTERASE IN RESISTANT INDIVIDUALS OF DIAMONDBACK MOTH

乙酰胆碱酯酶（AChE）敏感性降低是小菜蛾对有机磷和氨基甲酸酯产生抗性的重要机制之一，已得到广泛的承认和报道。一种用硝酸纤维素膜的斑点法鉴定个体小菜蛾的抗性AChE不敏感性的应用技术，提供了早期侦测和随后监测田间种群抗性的可能性。此法操作简便灵敏。小菜蛾抗性品系（GBR）和田间种群成虫头部AChE活力，在残杀威抑制时，抑制率分别为50．97％和43．96％，有对氧磷存在时，分别为63．78％和35．87％，较敏感品系的AChE为不敏感。

Acetylcholinesterase insensitivity is an important mechanism of resistance of diamondback moth (Plutella xylostella (L. )) to organophosphorus and carbamate insecticides, which has been widely recognized and documented. A dot-blot on nitrocellulose membranes technique for identification of insensitive AChE in single insect provides the opportunity for early detection and subsequent monitoring of resistance in field population. The technique is simple, sensitive and inexpensive. The percentages of inhibition of AChE activities in resistant strain (GBR) and field population (DG) were 50. 97% and 43. 96% respectively in the presence of propoxur and were 63. 76 % and 35. 87 % respectively in the presence of paraoxon. The results showed the GBR and DG had a higher degree of AChE insensitivity to OP and carbamate than did the susceptible strain.