Molecular phylogenetic geography of pan tropic sea dispersed plants

泛热带植物中有许多海流分散的种类。对于陆生植物来说，海洋是地理上的障碍，阻碍了它们的传播，但海洋有助于海流传播的植物的传播，并促进了它们种群之间的基因交换。本工作的目的是：1）了解在世界范围内广泛分布的泛热带物种之间的遗传交换程度。2)为探讨海流传播植物的起源，我们在太平洋、大西洋和印度洋沿岸地区搜寻了典型的泛热带植物--因此，我们几乎可以覆盖他们的分布区。在它们的种群中，我们收集了干叶样品用于DNA分析，干标本，固定在FAA中的花标本和种子。pes-captured检测的CPDNA区域的序列在所有群体之间没有变化。这表明我。寄生虫经常在种群之间迁移。另一方面，二氢黄酮醇4-还原酶（DFR-B）的第三内含子序列存在许多变异。pes-captured。这表明种群间存在遗传分化，尤其是太平洋、大西洋和印度洋之间的遗传分化。对琉球群岛沿海地区的海漂种子和果实进行了鉴定，并讨论了它们的海上扩散能力。

Among the pan tropic plants there are many sea current dispersed species. For land plants the oceans act as geographical barriers to disperse, but help dispersal of those sea current dispersed plants and progress the interchange of genes between their populations. The purposes of this work are 1) to know to what extent the genetic interchanges are occurred between the pan tropically distributed species which cover such a wide range round the world. 2) To discuss the origin of sea current dispersal plants.We searched native populations of typically pan tropic species, Ipomoea pes-caprae and Canavalia rosea in coastal regions of the Pacific, Atlantic and Indian Oceans, and made population sampling of them. As a result we could cover almost their distribution area. At their populations we collected dried leaf samples for DNA analysis, dried specimens, flower specimens fixed in FAA and seeds.In I. pes-caprae there was no variation of the sequences of the regions of CPDNA examined between all the populations. It suggests I. pes-caprae frequently immigrates between populations. On the other hand, there are many variations of the sequences of the third intron of dihydrofavonol 4-reductase (DFR-B) of I. pes-caprae. This indicates that the genetic differentiations occur among populations, especially between the Pacific, Atlantic and Indian oceans.Expansions of some sea current species, Hibiscus tiliaceus, Canavalia rosea, Mucuna gigantea by sea were discussed. Sea drifted seeds and fruits on the coastal regions of the Ryukyu archipelago were identified and their sea dispersal ability were discussed.