Pan Shin-Hung, Sun Ying-Hsuan, Tzeng Hsy-Yu, Rodriguez Lillian Jennifer, Bain Anthony
Department of Forestry, National Chung-Hsing University, 250 Kuokwang Road, Taichung 40227, Taiwan.
Institute of Biology, National Science Complex, College of Science, University of the Philippines, Diliman, Quezon City 1101, Philippines.
Plants (Basel). 2024 May 17;13(10):1398. doi: 10.3390/plants13101398.
Plants distributed between southern Taiwan and the north of the Philippines are spread among numerous small islands in an area crossed by the powerful Kuroshio current. Oceanic currents can be effective seed-dispersal agents for coastal plant species. Moreover, the Luzon Strait is an area prone to tropical cyclones. The aim of this study is to look at the dispersal capability of an endangered coastal plant species, the Mearns fig ( var. ), using both experimental and population genetics methods.
Southern Taiwan, the Philippines, and the islands between Luzon and Taiwan Island.
This study combined two types of analysis, i.e., buoyancy experiments on syconia and double digest restriction-associated DNA sequencing (ddRAD), to analyze the population genetics of the Mearns fig.
We first discovered that mature Mearns fig syconia could float in seawater. They have a mean float duration of 10 days to a maximum of 21 days. Germination rates varied significantly between Mearns fig seeds that had undergone different durations of flotation treatment. Population genetic analysis shows a high degree of inbreeding among various Mearns fig populations. Moreover, no isolation by distance was found between the populations and individuals.
From our analysis of the genetic structure of the Mearns fig populations, we can clearly highlight the effect of the Kuroshio oceanic current on the seed dispersal of this fig tree. Comprehensive analysis has shown that Mearns fig seeds are still viable before the mature syconium sinks into the seawater, and so they could use the Kuroshio Current to float to the current population locations in Taiwan.
分布于台湾南部和菲律宾北部的植物散布在众多小岛屿上，该区域有强大的黑潮洋流穿过。洋流可能是沿海植物物种有效的种子传播媒介。此外，吕宋海峡是一个热带气旋频发的区域。本研究的目的是运用实验和群体遗传学方法，研究一种濒危沿海植物——麦氏榕（变种）的传播能力。
台湾南部、菲律宾以及吕宋岛和台湾岛之间的岛屿。
本研究结合了两种分析方法，即对榕果进行浮力实验和双酶切限制性相关DNA测序（ddRAD），以分析麦氏榕的群体遗传学。
我们首次发现成熟的麦氏榕榕果能够漂浮在海水中。它们的平均漂浮时长为10天，最长可达21天。经过不同时长漂浮处理的麦氏榕种子，其发芽率差异显著。群体遗传学分析表明，各个麦氏榕种群存在高度的近亲繁殖现象。此外，在种群和个体之间未发现距离隔离现象。
通过对麦氏榕种群遗传结构的分析，我们能够清晰地凸显黑潮洋流对这种榕树种子传播的影响。综合分析表明，在成熟榕果沉入海水之前，麦氏榕种子仍具有活力，因此它们可以借助黑潮洋流漂浮至台湾目前的种群分布地点。
