星豹蛛不同地理种群COⅠ基因序列差异初步分析

POPULATION GENETIC STRUCTURE OF PARDOSA ASTRIGERA BASED ON MOLECULAR EVIDENCE FROM MTDNA

星豹蛛广泛分布于我国南北各省的农田、果园、菜田及森林等生态系统中,是农林害虫的重要天敌。本文测定了采自山西临汾、运城、晋中和忻州4个地区的星豹蛛地理种群细胞色素氧化酶亚基Ⅰ(COⅠ)基因部分序列(932bp),并对此序列及从NCBI网站GenBank上下载的采自国内10个省市星豹蛛相应序列一并进行遗传多样性研究,分析了碱基组成和变异情况以及核苷酸序列差异,采用距离矩阵邻接法和最大简约法构建了不同的分子系统树,得到了相似的拓扑结构,从分子水平初步探讨了星豹蛛不同地理种群的遗传结构。结果表明,星豹蛛地理种群间的COⅠ序列同源性达98%～100%,显示出较大的遗传差异。序列比对后从供试14个COⅠ序列中共检测出41个变异位点和6个单倍型,系统发育分析结果表明种群间存在一定的遗传分化。综合分析,星豹蛛不同地理种群之间的遗传差异较大,遗传多样性水平较高,进一步从分子遗传学角度证明了星豹蛛成为我国广布种的原因。

Pardosa astrigera widely distributed in most areas of South and North China. In order to clarify the genetic relationship of the different geographic populations of Pardosa astrigera, the 932 bp segment of the mitochondrial cytochrome oxidase subunit Ⅰ（COⅠ） gene sequences were determined from fourteen geographic populations in China, and the sequence variability of the COⅠgene and genetic differentiation among them were analyzed. The identity of COⅠpairwise sequences was 98 %-100 % among the geographic populations of Pardosa astrigera, which indicated a rather high genetic diversity. By pair-wise comparison, Kimura2-parameter distance and base substitution among these sequences were analyzed with the MEGA software package. Accordingly, the base composition of Pardosa astrigera showed the same character as that of other mammals. Simultaneously, the phylogenetic trees constructed by multiple methods （NJ and MP） supported almost the same topology. Six haplotypes were identified within the sequences, with forty-one sites showing polymorphism. Phylogenetic analysis showed that genetic differentiation existed definitely in different geographic populations. The result showed that the natural population of the Pardosa astrigera has abundant genetic diversities and there are differences in the genetic diversity of the population from different geographical regions, which furtherly proved from the perspective of molecular genetics that Pardosa astrigera is a widespread species in China.