Pandanus boninensis, endemic to the Ogasawara Islands, Japan, is distributed on both the older Bonin and younger Volcano Islands. In this study, we conducted population genetic analyses of P. boninensis on these islands to examine the population diversity and structure across old and young islands, to assess potential differences in population demography with island age, and to collect any evidence of migration between old and young islands. We found that the genetic diversity of expressed sequence tag (EST)-based microsatellite (SSR) markers, the nucleotide diversity of nuclear DNA sequences, and the haplotype diversity of chloroplast DNA on young islands were lower than those on old islands. Clustering analyses of EST-SSR indicated that populations on old islands were strongly diverged from those on young islands. Approximate Bayesian computation analysis of EST-SSR suggested that population expansion occurred on old islands while population reduction occurred on young islands. We also found evidence of migration among old islands (mostly from south to north), while it appears that there have been very few migration events between old and young islands. These differences could be due to the fact that young islands tend to be geographically isolated and support smaller populations that began a shorter time ago from limited founders. The P. boninensis populations on the Volcano Islands are interesting from an evolutionary perspective as they constitute a classic example of the early stages of progressive colonization on oceanic islands with small effective population sizes and low genetic diversity.

中文翻译：

---

日本小gas原群岛特有海漂移种子的露兜树（Pandanaceae）的遗传多样性，结构和人口统计学：新老岛屿之间的比较。

日本小gas原群岛特有的露兜树boninensis分布在较旧的波宁和较年轻的火山岛上。在这项研究中，我们对这些岛屿上的波尼松对虾进行了种群遗传学分析，以研究老龄岛和年轻岛上的种群多样性和结构，评估人口统计学随岛龄的潜在差异，并收集任何古迹和古迹之间迁移的证据。年轻的岛屿。我们发现，在年轻的岛屿上，基于表达序列标签（EST）的微卫星（SSR）标记的遗传多样性，核DNA序列的核苷酸多样性以及叶绿体DNA的单倍型多样性均低于旧岛屿。EST-SSR的聚类分析表明，旧岛上的人口与年轻岛上的人口有很大差异。EST-SSR的近似贝叶斯计算分析表明，人口增长发生在旧岛上，而人口减少发生在年轻岛上。我们还发现了旧岛之间迁移的证据（主要是从南到北），而旧岛和年轻岛之间的迁移事件似乎很少。造成这些差异的原因可能是，年轻的岛屿在地理上往往是孤立的，并且支持的人口较少，而这些人口是在有限的创始人之前开始的。从进化的角度来看，火山岛上的波尼松对虾种群很有趣，因为它们构成了有效种群数量少，遗传多样性低的大洋岛屿上渐进殖民化早期阶段的经典例子。