Molecular phylogenetic geography of pan tropic sea dispersed plants : Gene flow and species differentiation through geographic barrier.

泛热带海散植物广泛分布于世界热带海岸。通过对采自热带和亚热带地区的大量样本进行群体遗传学分析，了解了它们的种分化过程和种群间的基因流动情况，构建了系统发育树，分析了它们的亲缘关系。在太平洋、大西洋和印度洋三个区域，罗非鱼的三种主要单倍型分布广泛且重叠。F_1<ST>和AMOVA分析结果表明，三个海区的罗非鱼种群间没有明显的遗传分化。这些结果表明，大量的基因流发生在不同的海洋区域，由于海漂种子的群体之间。很强的遗传差异B ...更多信息 结果表明，太平洋和大西洋种群间的基因流动受到了抑制。Pernambucensis和H.tiliaceus在大西洋地区的广泛分布表明，这两个物种之间存在着显著的基因渗入。印度洋的一个小岛屿。虽然这两个亚种都有海中散布的种子，但它们在印度洋的分布范围是重叠的。通过AFLP分子标记的分析，可以清楚地观察到这些亚种之间的遗传分化。此外，还观察到远距离种群之间的基因流动。刀豆属植物约有50种，主要分布于世界热带和亚热带地区。其中，玫瑰茄等几种植物在热带、亚热带分布广泛。利用nrDNA ITS序列构建的系统发育树表明，夏威夷特有的Maunaloa亚属起源于以海漂扩散方式迁移到夏威夷的玫瑰珊瑚，并在形成过程中丧失了海漂能力。少

Pan tropic sea dispersed plants are widely distributed on the sea coast of the world tropics. Their population genetics were analyzed on many samples gathered from all over the tropics and subtropics to know their differentiation process into species and rates of gene flows between populations to keep the species.A phylogenetic tree constructed using the nucleotide sequences of a c.7,500 bp portion of chloroplast DNA suggested the possibility that recurrent speciation from H.tiliaceus has given rise to all of its allied species. Three major sequence haplotypes of H.tiliaceus had wide and overlapping distributions throughout the Pacific, Atlantic and Indian Ocean regions. Statistical analysis using F_<ST> and AMOVA did not show significant genetic differentiation among the H.tiliaceus populations in the three oceanic regions. These results suggested substantial gene flow occurred between populations in the different oceanic regions due to sea-drifted seeds. A strong genetic difference b … More etween the Pacific and Atlantic populations of H.pernambucensis was observed, which indicates that gene flow in this species between the two regions has been prevented. The wide and dominant distribution of a haplotype shared by H.pernambucensis and H.tiliaceus in the Atlantic region suggests significant introgression between the two species in this region.Ipomoea pes-caprae is divided into two geographical subspecies, subsp.brasiliensis distributed in the world tropics and subsp. pes-caprae of the Indian Ocean. Although both subspecies have sea-dispersed seeds, their distribution ranges are overlapped in the Indian Ocean. By the analysis using AFLP marker the genetic differentiation between these subspecies was clearly observed. Moreover gene flows among distant populations were observed. Geographic distance was slightly correlated with genetic distance.The genus Canavalia consists of about 50 species mostly distributed in the world tropics and subtropics. Among them several species as C.rosea have wide distribution range over the tropics and subtropics. Phylogenetic tree constructed by ITS sequences of nrDNA using extensive samples suggested that the Hawaiian endemic subgen.Maunaloa was derived from C.rosea that migrated to Hawaii by sea-drift dispersal, and loss of sea-drift ability occurred in the speciation process. Less