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双斑长跗萤叶甲Monolepta hieroglyphica(Motschulsky)是自2001年以来在我国北方为害玉米呈加重趋势的一种害虫。为初步探讨中国北方不同地理种群间和种群内该害虫的遗传分化程度、遗传多样性以及基因流水平,对来自中国北方的26个不同地理种群的线粒体COⅡ(细胞色素C氧化酶亚基Ⅱ)基因片段序列的核苷酸多态性进行了研究。结果表明:在515头个体的长度为484bpCOⅡ片段中共发现了28个变异位点和15种单倍型。单倍型间的系统进化分析发现,15种单倍型主要分为两大分支。总种群单倍型多样性指数Hd为0.257,种群内单倍型多样度在0.100～0.515范围内。总种群的Fst为0.585,Gst为0.417,基因流Nm为0.35。AMOVA分子变异分析结果发现,双斑长跗萤叶甲的遗传分化主要来自种群之间,占方差比率的58.58%。实验总种群及大部分种群的中性检验符合中性突变,说明我国北方双斑长跗萤叶甲在近期没有出现种群扩张现象。研究结果揭示中国北方双斑长跗萤叶甲不同地理种群间基因流水平低,种群间已发生明显的遗传分化,分化主要来自种群之间。
Monolepta hieroglyphica (Motschulsky) is a pest that has been on the increase in maize in northern China since 2001. In order to investigate the genetic differentiation, genetic diversity and gene flow of pests in different geographical populations and populations in northern China, mitochondrial COⅡ (cytochrome C oxidase subunit Ⅱ) polymorphism in 26 geographic populations from northern China Nucleotide polymorphisms of the gene fragment sequences were studied. The results showed that a total of 28 variation loci and 15 haplotypes were found in the 484 bp length of the 515 individuals. Phylogenetic analysis of haplotypes found that 15 haplotypes were divided into two major branches. The haplogroup diversity index Hd of the total population was 0.257, and the haplotype diversity within the population ranged from 0.100 to 0.515. The total population had a Fst of 0.585, a Gst of 0.417 and a gene flow of Nm of 0.35. AMOVA molecular variation analysis found that the genetic differentiation of Diabrotica philoxeroides mainly came from among the populations, accounting for 58.58% of the variance ratio. Neutral test of the experimental population and most of the population was consistent with the neutral mutation, indicating that there is no population expansion phenomenon in China in the recent years. The results revealed that the gene flow in different geographic populations of Diabrotica philoxeroides in northern China was low and significant genetic differentiation had occurred among populations. The differentiation mainly came from among populations.