关键词：
尼氏钝绥螨;抗亚胺硫磷;遗传;半显性;交互抗性;拟单倍性
摘 要：
尼氏钝绥螨Amblyseius nicholsi Ehara et Lee是桔全爪螨Panonychus citri(McGregor)的有效天敌之一。为了筛选抗有机磷农药品系,经实验室内用亚胺硫磷33次处理后,抗性提高18.9倍,LC_(50)从最初的52.5ppm提高到995ppm,为大田常用浓度的两倍。S(敏感型)与R(抗性型)的LD-P线近于平行,表明两者已成为纯系。正交与反交之F1_代雌性个体的LD—P线介于S与R之间略偏向R方,F_1显性度(D)大于0而小于1,说明抗性为半显性。F_1(杂合子)与敏感亲本的回交结果,其LD—P线在50％。死亡率处出现一平坡,SR(杂合子)与SS(敏感个体)的分配比例接近于1:1的理论值。以上结果说明尼氏钝绥螨对亚胺硫磷的抗性为半显性的单基因所控制。正、反交F_1代雄性个体的抗性检测结果表明,F_1代的雄性个体具有其遗传性来自母系的特征。尼氏钝绥螨抗亚胺硫磷品系对辛硫磷、水胺硫磷、乐果、敌敌畏、敌百虫等有机磷农药具有一定的交互抗性,抗性分别提高28.5、8.5、5.4、3.8和2.9倍。
译 名：
THE SELECTION FOR AND GENETICAL ANALYSIS OF PHOSMET RESISTANCE IN AMBLYSEIUS NICHOLSI
作 者：
HUANG MING-DU XIONG JIN-JUN DU TONG-YUAN(Guangdong Entomologtcal Institute)
关键词：
Amblyseius nicholsi——phosmet resistance——genetics——semidominan-ce——cross-resistance——parahaploidy
摘 要：
The predacious mite Amblyseuts nicholsi is an important natural enemy of the citrus red mite Panoopychus citri. However, this predator is very susceptible to organophosphorus (OP) insecticides such as phosmet and dimethoate, whlch are commonly used in Guangdong Province to control the citrus psylla Diaphorina citri, a vector of citrus yellow shoot disease. It is neces-sary to raise the resistance of the predator to OP insecticides so that they can be used in the citrus groves in combination.Determination of phosmet resistance of this predator was conducted by the slide-dip method of the laboratory population collected from Guangzhou and selection was started in June, 1982, with phosmet in ascending concentrations starting with 60 ppm of active ingrdient. After 33 generations of selection a resistant strain (R) was obtained, with LC50 for phosmet rising to 995 ppm as compared with 52.5 ppm in the original susceptible population (S). Thus, a 18.9-fold increase in resistance for phosmet was obtained in June, 1984, and the LD-P lines of R and S were nearly parallel. The LD-P lines of 1i females of reoiprocal crosses (S♀×Rf4 and R♀× S♂) were intermediate between those of R and S, and sliglitly closer to the former. The degree of dominance of F1 female hybrids were 1.4 and 1.9, indicating that the phosmet resistance is determined by semidominant gene. In the female offspring from heterozygote females back-crossed with S males, the ratio of SS to SR is approximately 1:1 and a plateau appears a't the 50% mortality of the LD-P line? It is concluded that resistance to phosmet in this predator is controlled by a single semidominant allele. An examination of resistance of F1 male hybrids of reciproca) crosses (S♂ × R♀ and R♀ × S♂) revealed that F1 males inherited the resistant gene from their mothers, exemplifying the parahaploidy model in some species of Phytoseiidae. The high cross-resistance to phoxim and weak cross-resistance to optunal, dimethoate, vapona, and trichlorfor were found present in the phosmet resistant strain and the resistance levels for these five insecticides have been improved to 28.8, 8.5, 5.4, 3.8 and 2.7 fold respectively.
