甘蔗绵蚜不同地理种群异柠檬酸脱氢酶（IDH）的多样性

用等位酶分析方法对三个用药背景不同的甘蔗绵蚜地理种群在9种酶（EST，G3PD，HEX，IDH，LDH，MDH，ME，PGI和PCM）上的遗传组成进行检测。结果显示：甘蔗绵蚜在9种酶共检测到9个等位酶位点，仅IDH位点具有多态性。在多态性的IDH位点共检测到3个等位基因，其中连续两年未曾用药的两院种群和用药较少的木棠种群均具有三个等位基因（a,b和c），而用药次数最多的临高种群仅存在两个等位基因（a和b）。等位基因a的频率从两院种群到临高种群逐渐升高，而等位基因b的频率却逐渐降低。说明IDH在甘蔗绵蚜的种群遗传进化过程中起着重要作用，杀虫剂的选择压力可能对甘蔗绵蚜地理种群的遗传结构具有分化作用，同时也说明IDH在甘蔗绵蚜对杀虫剂的抗性产生中具有重要作用。IDH-a频率的升高，可能导致甘蔗绵蚜对杀虫剂产生抗性，可通过检测IDH位点等位基因频率的变化来监测甘蔗绵蚜对杀虫剂的抗性。

Isocitrate dehydrogenase (IDH) diversity in Ceratovacuna lanigera Zehntne populations from different localities

The genetic compositions in 9 enzymes （ EST, G3PD, HEX, IDH, LDH, MDH, ME, PGI and PGM） of Ceratovacuna lanigera populations from 3 localities were analyzed based on allozyme electrophoresis results. The results demonstrated 9 loci in the 9 enzymes. And among them only IDH was polymorphic and 3 alleles were detected. In populations from LY where no insecticides were administered in the past 2 years, and from MT, where only a small amount of insecticides were administered, allele a, b and c were found, but in the population from LG, where insecticides were used most often, allele c was absent. Allele frequency of Idh- a increased from LY to LG, but that of Idh-b decreased. The results suggested that IDH might play an important role in population genetic evolution of C. lanigera and selection pressure from insecticides could accelerate genetic structure differentiation. The increased Idh-a frequency might be among the resistance mechanisms of C. lanigera to insecticides. Therefore, the variances in allele frequencies of C. lanigera at IDH locus might be a useful as a potential biomarker in insecticide resistance monitoring.