【摘要】 【目的】揭示中国草地螟Loxostege sticticalis不同地理种群的遗传分化程度。【方法】采用PCR技术扩增中国西北和华北地区草地螟11个地理种群的线粒体COⅠ,Cytb和COⅡ基因序列,基于其序列变异及单倍型贝叶斯系统发育树和单倍型网络图分析,探讨不同地理种群间的遗传距离、分子系统发生关系及遗传分化程度。【结果】草地螟11个地理种群的线粒体COⅠ,Cytb和COⅡ基因序列分别有24, 12和69个变异位点(分别占总序列的3.6%, 2.7%和8.8%),检测到的单倍型分别为22, 14和16个,单倍型多样度(Hd)分别为0.7600, 0.5842和0.7341,核苷酸平均差异度(K)分别为1.704, 0.752和3.997,不同单倍型间的遗传距离平均值分别为0.004, 0.005和0.013。总种群的Tajima’s D和Fu’s Fs值皆不显著,表明草地螟不同地理种群间的遗传分化不明显,群体大小稳定。根据各地理种群的单倍型建立的系统发育树和单倍型网络图表明,各单倍型散布在不同的地理种群中,无明显的地理分布格局。【结论】草地螟各地理种群的遗传距离与地理距离间不具有显著的相关性,其遗传分化不明显。更多还原

【Abstract】 【Aim】 To investigate the genetic differentiation of different geographic populations of Loxostege sticticalis in China. 【Methods】 The mitochondrial COⅠ, Cytb and COⅡ sequences from 11 geographic populations of L. sticticalis in Northwest and North China were amplified by PCR, and the genetic distance, molecular phylogeny and degree of genetic differentiation were analyzed based on their sequence variation, Bayesian inference(BI) phylogenetic tree and haplotype network. 【Results】 The sequence fragments of mitochondrial COⅠ, Cytb and COⅡ from 11 geographic populations of L. sticticalis had 24, 12 and 69 variable sites, respectively(accounting for 3.6%, 2.7% and 8.8% of the total length, respectively), 22, 14 and 16 haplotypes with the haplotype diversity(Hd) of 0.7600, 0.5842 and 0.7341, respectively, and the average nucleotide difference(K) of 1.704, 0.752 and 3.997, respectively. The average genetic distance based on mitochondrial COI, Cytb and COII sequences between different haplotypes was 0.004, 0.005 and 0.013, respectively. Both the Tajima’s D and Fu’s Fs of the total population were not significant, suggesting that the genetic differentiation among different geographic populations of L. sticticalis is not significant and the population size remains stable. The phylogenetic tree and haplotype network based on the haplotypes showed that the haplotypes were highly mixed in different geographic populations, without clear geographical distribution pattern. 【Conclusion】 The genetic distance between geographic populations of L. sticticalis is not significantly correlated with their geographical distance, and there is no obvious genetic differentiation between these populations.更多还原