Cho Myong-Suk, Takayama Koji, Yang JiYoung, Maki Masayuki, Kim Seung-Chul
Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea.
Department of Botany, Graduate School of Science, Kyoto University, Kyoto, Japan.
Front Plant Sci. 2021 Sep 2;12:706195. doi: 10.3389/fpls.2021.706195. eCollection 2021.
Of the two major speciation modes of endemic plants on oceanic islands, cladogenesis and anagenesis, the latter has been recently emphasized as an effective mechanism for increasing plant diversity in isolated, ecologically homogeneous insular settings. As the only flowering cherry occurring on Ulleung Island in the East Sea (concurrently known as Sea of Japan), Nakai has been presumed to be derived through anagenetic speciation on the island. Based on morphological similarities, Rehder distributed in adjacent continental areas and islands has been suggested as a purported continental progenitor. However, the overall genetic complexity and resultant non-monophyly of closely related flowering cherries have hindered the determination of their phylogenetic relationships as well as the establishment of concrete continental progenitors and insular derivative relationships. Based on extensive sampling of wild flowering cherries, including and from Ulleung Island and its adjacent areas, the current study revealed the origin and evolution of using multiple molecular markers. The results of phylogenetic reconstruction and population genetic structure analyses based on single nucleotide polymorphisms detected by multiplexed inter-simple sequence repeat genotyping by sequencing (MIG-seq) and complementary cpDNA haplotypes provided evidence for (1) the monophyly of ; (2) clear genetic differentiation between (insular derivative) and (continental progenitor); (3) uncertain geographic origin of , but highly likely via single colonization from the source population of in the Korean Peninsula; (4) no significant reduction in genetic diversity in anagenetically derived insular species, i.e., , compared to its continental progenitor ; (5) no strong population genetic structuring or geographical patterns in the insular derivative species; and (6) MIG-seq method as an effective tool to elucidate the complex evolutionary history of plant groups.
在海洋岛屿特有植物的两种主要物种形成模式——分支进化和前进进化中，后者最近被强调为在孤立、生态同质的岛屿环境中增加植物多样性的有效机制。作为东海（又称日本海）郁陵岛唯一的开花樱桃，中井樱桃被推测是通过该岛的前进进化物种形成而来。基于形态相似性，分布在相邻大陆地区和岛屿的李被认为是所谓的大陆祖先。然而，亲缘关系密切的开花樱桃的整体遗传复杂性以及由此导致的非单系性，阻碍了确定它们的系统发育关系，也阻碍了确定具体的大陆祖先和岛屿衍生关系。基于对野生开花樱桃的广泛采样，包括郁陵岛及其邻近地区的样本，本研究使用多种分子标记揭示了中井樱桃的起源和进化。基于通过多重简单序列重复测序基因分型（MIG-seq）检测到的单核苷酸多态性以及互补的叶绿体DNA单倍型进行的系统发育重建和群体遗传结构分析结果，为以下几点提供了证据：（1）中井樱桃的单系性；（2）中井樱桃（岛屿衍生种）和李（大陆祖先）之间明显的遗传分化；（3）中井樱桃的地理起源不确定，但很可能是通过从朝鲜半岛李的源种群单次定殖而来；（4）与大陆祖先李相比，通过前进进化衍生的岛屿物种中井樱桃的遗传多样性没有显著降低；（5）岛屿衍生物种中没有强烈的群体遗传结构或地理模式；（6）MIG-seq方法是阐明植物类群复杂进化历史的有效工具。
