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【目的】大豆食心虫Leguminivora glycinivorella(Matsumura)是一种危害大豆的主要害虫,在中国北方地区危害较重。本研究旨在探讨大豆食心虫在中国东北不同地理种群间的遗传变异。【方法】测定了10个不同地理种群153个个体的线粒体细胞色素氧化酶亚基Ⅰ(mtCOI)基因的657 bp序列,利用DnaSP 5.0和Arlequin 3.5.1.2等软件对大豆食心虫种群间的遗传多样性、基因流水平和分子变异进行分析。【结果】结果表明:10个地理种群间的COI基因共有36个变异位点和17个单倍型,其中1个单倍型为10个种群所共享。总种群的单倍型多样性指数Hd为0.456,各地理种群单倍型多样度范围在0~0.634之间。总群体的固定系数Fst为0.12545,遗传分化系数Gst为0.06326,总基因流Nm为3.49,且各种群间的基因流均大于1,种群间基因交流的水平较高。【结论】大豆食心虫种群内遗传多样性水平处于中低等水平。总群体和各种群的Tajima’s D检验结果皆不显著,说明中国东北地区大豆食心虫在较近的历史时期内没有出现种群扩张现象。AMOVA分子变异分析结果表明,大豆食心虫的遗传分化主要来自种群内部,而种群间未发生明显的遗传分化。各地理种群的单倍型在系统发育树上和中介网络图上散布在不同的分布群中,缺乏明显的地理分布格局。各种群的遗传距离与地理距离之间没有显著线性相关性,种群间的基因交流并未受到地理距离的影响。
【Objective】 Soybean borer Leguminivora glycinivorella (Matsumura) is a major pest that endangers soybean and is more harmful in northern China. The aim of this study was to investigate the genetic variation of soybean borer in different geographic populations in Northeast China. 【Method】 The 657 bp sequence of mitochondrial cytochrome oxidase subunit Ⅰ (mtCOI) gene of 153 individuals from 10 different geographical populations was determined. The genetic diversity among populations of soybean borer was detected using softwares DnaSP 5.0 and Arlequin 3.5.1.2. , Gene flow and molecular variation analysis. 【Result】 The results showed that there were 36 variation sites and 17 haplotypes in COI gene among 10 geographic populations. One haplotype was shared by 10 populations. The haplogroup diversity index Hd of the total population was 0.456, and the haplotype diversity ranged from 0 to 0.634. The total population had a fixed coefficient Fst of 0.12545, a genetic differentiation coefficient of Gst of 0.06326, and a total gene flow of Nm of 3.49, with gene flow greater than 1 across all groups and a higher level of gene exchange among the populations. 【Conclusion】 The level of genetic diversity in soybean borer is at low to intermediate level. The results of Tajima’s D test of the total population and each population were not significant, indicating that there was no population expansion in soybean northeastern China during the recent historical period. AMOVA molecular variation analysis showed that the genetic differentiation of soybean borer mainly came from within the population, but no obvious genetic differentiation among the populations. The haplotypes of each geographical population were scattered in different distribution groups on the phylogenetic tree and the intermediary network map, lacking obvious geographical distribution pattern. There was no significant linear correlation between the genetic distances and geographic distances of all groups, and the genetic exchanges among the populations were not affected by geographical distance.