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

泛热带海洋分散植物的分子系统发育地理学：通过地理屏障的基因流和物种分化。

基本信息

批准号：
14405015
负责人：
TATEISHI Yoichi
金额：
$ 8万
依托单位：
University of the Ryukyus
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

项目摘要

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

泛热带海洋分散植物广泛分布于世界热带沿海地区。对在热带和亚热带地区采集的大量样本进行种群遗传学分析，了解其物种分化过程和种群间保持物种的基因流动速率。利用叶绿体DNA中约7500 bp的核苷酸序列构建的系统发育树表明，H.tiliaceus的重复物种形成可能产生了其所有亲缘物种。三种主要序列单倍型在太平洋、大西洋和印度洋地区分布广泛且重叠。F_<ST>和AMOVA的统计分析表明，3个大洋地区的铁牙属居群间没有明显的遗传分化。这些结果表明，由于海洋漂流的种子，在不同海洋区域的种群之间发生了大量的基因流动。在太平洋种群和大西洋种群之间观察到强烈的遗传差异，这表明该物种在两个地区之间的基因流动已经被阻止。在大西洋地区，H.pernambucensis和H.tiliaceus共有的一个单倍型广泛而优势分布，表明这两个物种在该地区存在显著的遗传渐近。在地理上分为两个亚种，亚种。巴西属植物分布于世界热带及亚种。印度洋的蹼足猿。虽然这两个亚种的种子都分散在海洋中，但它们在印度洋的分布范围是重叠的。通过AFLP标记分析，可以清楚地观察到这些亚种之间的遗传分化。此外，还观察到遥远种群之间的基因流动。地理距离与遗传距离略有相关。菜花属约有50种，主要分布在世界热带和亚热带。其中玫瑰花等几个种在热带和亚热带分布广泛。利用大量样本的nrDNA ITS序列构建的系统发育树表明，夏威夷特有亚属。毛纳罗亚是由海漂向夏威夷迁移的玫瑰藓衍生而来，在物种形成过程中发生了海漂能力的丧失。少