暗褐蝈螽不同地理种群间的遗传分化

Genetic differentiation among different geographic populations of Gampsocleis sedakovii

利用线粒体COI基因片段研究了我国吉林、辽宁、内蒙古、河北和四川的暗褐蝈螽(Gampsocleis sedakovii)12个地理种群间的遗传分化。结果表明:36条626bp的mtDNA-COI基因片段中共检测到单倍型29种,多态位点71个,其中简约信号位点37个,单一多态位点34个。分子变异等级分析(AMOVA)的计算结果显示,群体内变异仅占总变异的37.23%,明显小于群体间变异,Fst值为0.62770,各群体间呈现明显的遗传分化。最大简约法(MP)系统发育分析结果显示,暗褐蝈螽的12个地理种群以极高的自举支持度(100%)聚类,形成两个独立的分枝。由于两个分枝的聚类结果与基于形态学特征划分的两个亚种(Gampsocleis sedakovii sedakovii和Gampsocleis sedakovii obscura)并不对应。综合采集地的生境,初步推测暗褐蝈螽两个亚种间的形态学差异可能是由于它们所处生境不同所引起。在12个地理种群中,只有内蒙古通辽(NTL)的个体在两个分枝中均有出现。单倍型分布格局研究发现,单倍型H10是内蒙古通辽(NTL)、鄂温克(NEWK)和吉林吉林(JJL)3个地理种群的共享单倍型,说明它们来自于共同的祖先。研究结果支持我国的东北地区是暗褐蝈螽遗传分化中心的观点,但不支持基于形态学特征划分的两个亚种。

The mitochondrial cytochrome oxidase I（mtDNA-COI） gene was used to investigate the intraspecific genetic subdivision among 12 geographical populations of Gampsocleis sedakovii distributed in Jilin,Liaoning,Inner Mongolia,Hebei,and Sichuan provinces,China.As for the 626 bp mtDNA-COI sequences of 36 individuals,29 haplotypes and 71（11.3%） polymorphic sites were detected,including 37 parsimony informative and 34 singleton variable sites.The results of the analysis of molecular variance（AMOVA） showed that the percentage of variation within populations（37.23%） was less than that among populations.The Fst value was 0.62770（P 0.001）,and the genetic divergence among populations was significant.Maximum parsimony（MP） analysis revealed two clearly differentiated branch（Ⅰ and Ⅱ） with high bootstrap support（100%）.However,these two branches did not correspond in the subspecies distinction based on morphological character.Based on the habitats analysis,we preliminary inferred that morphological divergence between Gampsocleis sedakovii sedakovii and Gampsocleis sedakovii obscura was the result of habitat dissimilarity.The majority of the G.sedakovii individuals collected in NTL（Tongliao,Inner Mongolia） were identified as the members of branch Ⅱ,but one individual（NTL-3） belonged to branch Ⅰ.Thus,at least this locality was occupied by two phylogenetically independent individuals.Haplotypes（H10） were shared by three localities,NTL,NEWK（Ewenke,Inner Mongolia） and JJL（Jilin,Jilin）,indicated that they shared a common ancestor.We approved that Northeastern China（Manchuria China） was the center of G.sedakovii genetic differentiation,but disapproved the subspecies distinction based on morphological character.