小菜蛾对杀虫双的抗性遗传研究

GENETIC STUDY OF DIMEHYPO RESISTANCE IN DIAMOND BACK MOTH, PLUTELLA XYLOST ELLA L.

利用室内选育的敏感品系和抗杀虫双品系为亲本,采用剂量对数—死亡机率值回归线(LD-P线)分析法,研究了小菜蛾对杀虫双的抗性遗传方式。结果表明,小菜蛾对杀虫双的抗性为多基因、常染色体遗传,正、反交F_1的显性度(D)值分别为0.39、0.28,即其主效基因为不完全显性。小菜蛾对杀虫双的抗性现实遗传力较低,h^2=0.052,产生抗性的速率较慢,室内选育119代,抗性仅达122.8倍。抗杀虫双品系和遗传杂交后代(F_1、F_2、BC)对拟除虫菊酯类、氨基甲酸酯类、有机磷类的代表杀虫剂溴氰菊酯、灭多威、敌敌畏等的交互抗性测定结果表明,它们对3种杀虫剂无交互抗性;亲本和杂交后代的多功能氧化酶环氧化活性与杀虫双的抗性水平呈正相关性;乙酰胆碱酯酶活性要比敏感品系低;羧酸酯酶活性与敏感品系无明显差异。

The mode of inheritance of resistance to dimehypo in diamond back moth, Plutella xylostella L. was evaluated from log dosage-probit mortality curves constructed from the response of fourth instar larvae to dimehypo treatment. The insects used for the study were taken from laboratory reared susceptible and laboratory selected 119 generations resistant strains, which exhibited 122. 8-fold resistance to dimehypo as compared with the susceptible strain. The result of genetic study indicated that dimehypo resistance in diamond back moth, appeared to be controlled by two or more autosomal genes and the major genes involved were incompletely dominant. Degrees of dominace (D) are 0. 39(S ×R ) and 0. 28(R ×S ). The realized heritability(h2) of resistance to dimehypo in the insect is 0. 052 the developed rate and potential of the resistance are slow and low. The sensitivites of dimehypo resistant strains and filial generation had not marked cross-resistance to deltamthrin, methomyl, dichlorvos. The results of study on activity of MFO, AchE and CarE showed that the resistance of the insect to dimehypo was direct related to MFO. The activity of AchE is low as compared with the susceptible strain. The activity of CarE is almost the same as compared with the susceptible strain.