Gene flow and population subdivision in a pantropical plant with sea-drifted seeds Hibiscus tiliaceus and its allied species:: evidence from microsatellite analyses
Gene flow and population subdivision in a pantropical plant with sea-drifted seeds Hibiscus tiliaceus and its allied species:: evidence from microsatellite analyses
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DOI：
10.1111/j.1365-294x.2008.03799.x
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发表时间：
2008-06-01
影响因子：
4.9
通讯作者：
Kajita, Tadashi
中科院分区：
文献类型：
--
作者：
Takayama, Koji;Tateishi, Yoichi;Kajita, Tadashi
利用6个微卫星标记研究了泛热带海漂种子植物木槿（Hibiscustiliaceus）及其近缘种的遗传分化和遗传结构。H.在太平洋和印度洋地区的tiliaceus种群，类似于以前的叶绿体DNA（cpDNA）的研究结果。通过远距离种子传播的频繁基因流动是H.分布范围广。另一方面，高度分化的H.在西非检测到了黄皮菌，在巴西南部也检测到了巴西木槿。在以前的种群中，非洲大陆可能是一个地理障碍，阻止了海上漂流种子的基因流动。在后者的人口，虽然没有已知的土地障碍，分叉南赤道电流在巴西东北角可能是一个潜在的障碍，基因流，并可能促进这些人口的遗传分化。我们的研究结果还表明，H。tiliaceus和H. pemambucensis，这证实了这两个物种之间的渐渗情况，这是由以前的cpDNA研究所提出的。我们的结果也为最近通过洋流进行的跨大西洋远距离种子传播提供了很好的证据。尽管在cpDNA单倍型中观察到不同的地理结构，但在太平洋和大西洋种群之间发现了低水平的遗传分化。Pernambucensis，这可能是由transsthmian基因流引起的。
The genetic differentiation and structure of Hibiscus tiliaceus, a pantropical plant with sea-drifted seeds, and four allied species were studied using six microsatellite markers. A low level of genetic differentiation was observed among H. tiliaceus populations in the Pacific and Indian Ocean regions, similar to the results of a previous chloroplast DNA (cpDNA) study. Frequent gene flow by long-distance seed dispersal is responsible for species integration of H. tiliaceus in the wide distribution range. On the other hand, highly differentiated populations of H. tiliaceus were detected in West Africa, as well as of Hibiscus pernambucensis in southern Brazil. In the former populations, the African continent may be a geographical barrier that prevents gene flow by sea-drifted seeds. In the latter populations, although there are no known land barriers, the bifurcating South Equatorial Current at the north-eastern horn of Brazil can be a potential barrier to gene flow and may promote the genetic differentiation of these populations. Our results also suggest clear species segregation between H. tiliaceus and H. pemambucensis, which confirms the introgression scenario between these two species that was suggested by a previous cpDNA study. Our results also provide good evidence for recent transatlantic long-distance seed dispersal by sea current. Despite the distinct geographical structure observed in the cpDNA haplotypes, a low level of genetic differentiation was found between Pacific and Atlantic populations of H. pernambucensis, which could be caused by transisthmian gene flow.