甘肃省二斑叶螨地理种群的遗传分析
The genetic analysis of two-spotted spider mite Tetranychus urticae geographical populations in Gansu Province

为探讨甘肃省二斑叶螨Tetranychus urticae种群遗传多样性及遗传分化，通过mtDNA-COI基因DNA条形码技术对采自甘肃省8个不同生境35个二斑叶螨地理种群的582个样品进行序列分析及地理种群的遗传分化分析。结果表明，获得二斑叶螨mtDNA-COI基因片段大小为424 bp，其中保守序列336个，变异位点66个，简约信息位点45个，单突变位点21个；碱基（A+T）含量明显高于（C+G）含量，有明显的A/T碱性偏倚性；在35个地理种群中共检出16个单倍型，单倍型指数为0.906；Mantel检测结果表明种群间的遗传距离与地理距离显著相关性；35个地理种群间的遗传分化指数Fst为0.012，种群间变异为1.200。表明二斑叶螨的遗传变异主要来自于种群内部，种群间还未发生明显的遗传分化。
In order to study the population genetic variation and genetic diversity of two-spotted spider mite Tetranychus urticae in Gansu Province, 582 T. truncatus samples collected from 35 sampling points in eight different habitats of Gansu Province were analyzed based on mtDNA-COI gene sequences and by using DNA barcode technique. The results showed that there were 336 conserved sequences, 66 variation points, 45 parsimony informative sites and 21 single mutation sites in the sequenced fragments of 424 bp in length; the (A+T) content was apparently higher than (G+C) content, with an obvious A/T alkalinity bias. There were 16 haplotypes in 35 geographical populations with a haploid type index of 0.906. According to Mantel test results, no significant correlation was found between genetic distance and geographical distance. The genetic differentiation index (Fst) among 35 geographical populations was 0.012, and variation was 1.200. The results showed that the heritable variation of T. urticae was mainly from within populations, and there was no obvious genetic differentiation among populations.