Universidad San Francisco de Quito (USFQ), Colegio de Ciencias Biológicas y Ambientales, Laboratorio de Biotecnología Vegetal, Campus Cumbayá, Quito, Ecuador.
Department of Zoology, University of Oxford, South Parks Road, Oxford, United Kingdom.
PLoS One. 2019 Mar 13;14(3):e0203737. doi: 10.1371/journal.pone.0203737. eCollection 2019.
The threat of invasive plant species in island populations prompts the need to better understand their population genetics and dynamics. In the Galapagos islands, this is exemplified by the introduced guava (Psidium guajava), considered one of the greatest threats to the local biodiversity due to its effective spread in the archipelago and its ability to outcompete endemic species. To better understand its history and genetics, we analyzed individuals from three inhabited islands in the Galapagos archipelago with 11 SSR markers. Our results reveal similar genetic diversity between islands, and the populations appear to be distinct: the islands of San Cristobal and Isabela are genetically different while the population of Santa Cruz is a mixture from both. Additional evidence for genetic bottlenecks and the inference of introduction events suggests an original introduction of the species in San Cristobal, from where it was later introduced to Isabela, and finally into Santa Cruz. Alternatively, a second introduction in Isabela might have occurred. These results are contrasted with the historical record, providing a first overview of the history of P. guajava in the Galapagos islands and its current population dynamics.
入侵植物物种对岛屿种群构成威胁，促使人们需要更好地了解它们的种群遗传学和动态。在加拉帕戈斯群岛，这种情况以引入的番石榴（Psidium guajava）为例，由于其在群岛中的有效传播及其与本地特有物种竞争的能力，它被认为是对当地生物多样性的最大威胁之一。为了更好地了解其历史和遗传学，我们使用 11 个 SSR 标记分析了加拉帕戈斯群岛三个有人居住的岛屿上的个体。我们的研究结果表明岛屿之间的遗传多样性相似，而且种群似乎是不同的：圣克里斯托瓦尔岛和伊莎贝拉岛在遗传上有所不同，而圣克鲁斯岛的种群则是两者的混合。进一步的遗传瓶颈和引入事件的推断证据表明，该物种最初是在圣克里斯托瓦尔岛被引入的，随后被引入到伊莎贝拉岛，最后引入到圣克鲁斯岛。或者，在伊莎贝拉岛可能发生了第二次引入。这些结果与历史记录形成对比，提供了加拉帕戈斯群岛番石榴历史及其当前种群动态的概述。
