Puppo Pamela, Curto Manuel, Meimberg Harald
CIBIO Research Center in Biodiversity and Genetic Resources/InBio Associated Laboratory University of Porto Campus Vairão Vairão 4485-661 Portugal.
Institute for Integrative Nature Conservation Research University of Natural Resources and Life Sciences A-1180 Vienna Austria.
Ecol Evol. 2016 Apr 20;6(11):3443-3460. doi: 10.1002/ece3.2094. eCollection 2016 Jun.
Geological history of oceanic islands can have a profound effect on the evolutionary history of insular flora, especially in complex islands such as Tenerife in the Canary Islands. Tenerife results from the secondary connection of three paleo-islands by a central volcano, and other geological events that further shaped it. This geological history has been shown to influence the phylogenetic history of several taxa, including genus (Lamiaceae). Screening 15 microsatellite markers in 289 individuals representing the eight species of present in Tenerife, this study aims to assess the genetic diversity and structure of these species and its relation with the geological events on the island. In addition, we evaluate the extent of hybridization among species and discuss its influence on the speciation process. We found that the species restricted to the paleo-islands present lower levels of genetic diversity but the highest levels of genetic differentiation suggesting that their ranges might have contracted over time. The two most widespread species in the island, and , present the highest genetic diversity levels and a genetic structure that seems correlated with the geological composition of the island. Samples from from the oldest paleo-island, Adeje, appear as distinct while samples from segregate into two main clusters corresponding to the paleo-islands of Anaga and Teno. Evidence of hybridization and intraspecific migration between species was found. We argue that species boundaries would be retained despite hybridization in response to the habitat's specific conditions causing postzygotic isolation and preserving morphological differentiation.
海洋岛屿的地质历史会对岛屿植物群的进化历史产生深远影响，尤其是在加那利群岛的特内里费岛这样的复杂岛屿上。特内里费岛是由三座古岛屿通过一座中央火山以及其他进一步塑造它的地质事件二次连接而成的。业已表明，这种地质历史影响了包括薄荷属（唇形科）在内的几个分类群的系统发育历史。本研究在代表特内里费岛现存的薄荷属8个物种的289个个体中筛选了15个微卫星标记，旨在评估这些物种的遗传多样性和结构及其与该岛地质事件的关系。此外，我们评估了物种间杂交的程度，并讨论了其对物种形成过程的影响。我们发现，局限于古岛屿的物种遗传多样性水平较低，但遗传分化程度最高，这表明它们的分布范围可能随时间而缩小。该岛分布最广的两个物种，[物种名称1]和[物种名称2]，具有最高的遗传多样性水平，其遗传结构似乎与该岛的地质组成相关。来自最古老古岛屿阿德耶的[物种名称3]样本表现出独特性，而来自[物种名称4]的样本则分为对应于阿纳加和特诺古岛屿的两个主要聚类。发现了物种间杂交和种内迁移的证据。我们认为，尽管存在杂交现象，但由于栖息地的特定条件导致合子后隔离并保留形态分化，物种界限仍将得以维持。
