Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
Tokyo Metropolitan Ogasawara Islands Branch Office, Tokyo, Japan.
Sci Rep. 2024 Nov 9;14(1):27410. doi: 10.1038/s41598-024-78452-w.
The Ogasawara Islands, one of the UNESCO World Natural Heritage Site located about 1000 km south of Japan's main island, harbor numerous endemic species, many of which are as endangered. One of the endemic plant species, Lobelia boninensis, found in the Mukojima, Chichijima, and Hahajima archipelagoes, is endangered due to predation. As part of conservation efforts, translocation is now underway, especially on Chichijima. However, we lack essential information, such as the genetic population structure, to develop appropriate translocation strategies for both wild and planted individuals. Here, we aimed to identify the conservation units and the origin of planted individuals by estimating the genetic population structure and phylogenetic relationships across all habitats of this species. We identified two distinct genetic clusters, indicating genetic differentiation between the northern and southern populations. The genetic population components detected at an isolated site on Chichijima showed a mixture of these distinct clusters, probably due to hybridization. The transplanted individuals in Chichijima were found to have originated from a population in Hahajima. These results suggest the presence of two distinct conservation units. Furthermore, the current translocation strategy poses a risk of genetic contamination between these units, highlighting the need for revised conservation management practices.
小笠原群岛位于日本主岛以南约 1000 公里处，是联合国教科文组织世界自然遗产之一，拥有众多特有物种，其中许多物种濒临灭绝。在小笠原群岛的母岛、知床岛和八丈岛发现的特有植物物种之一——波里尼西亚风铃草，由于被捕食而濒危。作为保护工作的一部分，现在正在进行移植，特别是在知床岛。然而，我们缺乏必要的信息，例如遗传种群结构，无法为野生和种植个体制定适当的移植策略。在这里，我们旨在通过估计该物种所有栖息地的遗传种群结构和系统发育关系，确定保护单位和种植个体的起源。我们确定了两个不同的遗传群集，表明北部和南部种群之间存在遗传分化。在知床岛上一个孤立地点检测到的遗传种群成分显示出这些不同集群的混合，可能是由于杂交。在知床岛移植的个体起源于八丈岛的一个种群。这些结果表明存在两个不同的保护单位。此外，目前的移植策略存在这些单位之间遗传污染的风险，突出了需要修订保护管理实践。
