Genetic differentiation and delimitation of Pugioniumdolabratum and Pugionium cornutum (Brassicaceae)
Genetic differentiation and delimitation of Pugioniumdolabratum and Pugionium cornutum (Brassicaceae)
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DOI：
10.1007/s00606-013-0800-3
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发表时间：
2013-05
影响因子：
1.9
通讯作者：
Qiushi Yu;Qian Wang;Guili Wu;Yazhen Ma;Xinyu He;Xi Wang;Penghui Xie;Li-Mei Hu;Jianquan Liu
中科院分区：
文献类型：
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作者：
Qiushi Yu;Qian Wang;Guili Wu;Yazhen Ma;Xinyu He;Xi Wang;Penghui Xie;Li-Mei Hu;Jianquan Liu
物种划分一直是进化生物学的一个重要研究热点。然而，最近分化的物种的遗传界限取决于所检查的标记。在本研究中，我们的目的是研究两种pugionium gaertn（芸苔科）-Pugionium cornutum（L.）的遗传分化和划分。在中亚的沙漠生境中出现的Gaertn和pugionium dolabratummaxima，具有准栖息地分布。利用2个叶绿体DNA片段（trnV-trnM和trns - trnfm）、7个简单重复序列（SSR）位点和核糖体内转录间隔区（ITS），对来自25个群体的169个个体进行了基因分型。鉴定出4个cp单倍型，其中3个在两个物种中普遍存在，表明物种特异性谱系分类不完整。种间cpDNA分化（FCT）较低，甚至低于同一种居群间。SSR变量的贝叶斯聚类和最大似然遗传分析都将所有样本个体划分为两类，这与形态分离非常吻合，尽管根据SSR位点数据，物种之间存在明显的基因流动。然而，在所有样本中，两种类型的ITS序列与两种的形态划分高度一致。这些结果共同表明，这两个物种共享许多祖先cpDNA多态性，并指出核DNA （ITS或多位点遗传积累）在划分最近分化的物种中的重要性。
Species delimitation has been a major research focus in evolutionary biology. However, the genetic delimitation of recently diverged species varies depending on the markers examined. In this study, we aimed to examine genetic differentiation and delimitations between only two species ofPugioniumGaertn (Brassicaceae)—Pugionium cornutum(L.) Gaertn andPugionium dolabratumMaxim—that occur in the desert habitats of central Asia and have parapatric distributions. We genotyped 169 individuals from 25 populations, using two chloroplast (cp) DNA fragments (trnV-trnM andtrnS-trnfM), seven simple repeated sequence (SSR) loci and the nuclear ribosomal internal transcribed spacer (ITS). Four cp haplotypes were identified, three of which commonly occur in the two species, suggesting incomplete species-specific lineage sorting. Between-species cpDNA differentiation (FCT) was low, even lower than among populations of the same species. However, we found higher than average SSRFCTvalues, and both Bayesian clustering of SSR variables and maximum-likelihood genetic analyses divided all sampled individuals into two groups, agreeing well with morphological separation, although gene flow between species was obvious according to the SSR loci data. However, two types of ITS sequences were highly consistent with the morphological delimitation of the two species in all sampled individuals. These results together suggest that these two species shared numerous ancestral cpDNA polymorphisms and point to the importance of nuclear DNA (ITS or genetic accumulation at multiple loci) in delimiting recently diverged species.