Strong genetic differentiation of Primula sikkimensis in the East Himalaya-Hengduan Mountains
Strong genetic differentiation of Primula sikkimensis in the East Himalaya-Hengduan Mountains
复制标题
东喜马拉雅-横断山地区锡金报春的强烈遗传分化
DOI：
10.1007/s10528-007-9131-9
复制
发表时间：
2008-02-01
影响因子：
2.4
通讯作者：
Hao, Gang
中科院分区：
文献类型：
--
作者：
Wang, Feng-Ying;Ge, Xue-Jun;Hao, Gang
东喜马拉雅-横断山区是报春花属植物的多样性中心，锡金报春是该地区最常见的报春花属植物之一。本研究利用ISSR和叶绿体微卫星标记对中国锡金松居群的遗传多样性和遗传结构进行了分析。分析的254个个体代表13个群体。高水平的遗传多样性揭示了ISSR标记。在物种水平上，期望杂合度和Shannon指数分别为0.4032和0.5576。AMOVA分析表明，50.3%的遗传多样性分布在居群间。3对叶绿体微卫星引物共扩增出12个大小变异体和15个叶绿体单倍型。叶绿体DNA的遗传分化较强（G（ST）= 0.697），且存在明显的地理结构差异（N-ST = 0.788，显著高于G（ST））。花粉介导的基因流的估计速率比种子介导的基因流的估计速率高约27%。然而，种子和花粉的传播是有限的，种群之间的基因流动似乎受到物种栖息地的斑块和地理隔离的阻碍。这些特征可能在塑造锡金拟青霉的遗传结构中发挥了重要作用。构建了叶绿体DNA单倍型的最小生成树，并鉴定了锡金披碱草可能的冰川避难所。
The East Himalaya-Hengduan Mountains region is the center of diversity of the genus Primula, and P. sikkimensis is one of the most common members of the genus in the region. In this study, the genetic diversity and structure of P. sikkimensis populations in China were assessed using inter-simple sequence repeat (ISSR) and chloroplast microsatellite markers. The 254 individuals analyzed represented 13 populations. High levels of genetic diversity were revealed by ISSR markers. At the species level, the expected heterozygosity and Shannon's index were 0.4032 and 0.5576, respectively. AMOVA analysis showed that 50.3% of the total genetic diversity was partitioned among populations. Three pairs of chloroplast microsatellite primers tested yielded a total of 12 size variants and 15 chloroplast haplotypes. Strong cpDNA genetic differentiation (G(ST) = 0.697) and evidence for phylogeographic structure were detected (N-ST = 0.788, significantly higher than G(ST)). Estimated rates of pollen-mediated gene flow are approximately 27% greater than estimated rates of seed-mediated gene flow in P. sikkimensis. Both seed and pollen dispersal, however, are limited, and gene flow among populations appears to be hindered by the patchiness of the species' habitats and their geographic isolation. These features may have played important roles in shaping the genetic structure of P. sikkimensis. A minimum-spanning tree of chloroplast DNA haplotypes was constructed, and possible glacial refugia of P. sikkimensis were identified.