Spatial genetic structure and diversity of natural populations of Aesculus hippocastanum L. in Greece

PLoS One. 2019 Dec 11;14(12):e0226225. doi: 10.1371/journal.pone.0226225. eCollection 2019.

Abstract

Horse-chestnut (Aesculus hippocastanum L.) is an endemic and relict species from the Mediterranean biodiversity hotspot and a popular ornamental tree. Knowledge about the evolutionary history of this species remains scarce. Here, we ask what historical and ecological factors shaped the pattern of genetic diversity and differentiation of this species. We genotyped 717 individuals from nine natural populations using microsatellite markers. The influence of distance, topography and habitat variables on spatial genetic structure was tested within the approaches of isolation-by-distance and isolation-by-ecology. Species niche modeling was used to project the species theoretical range through time and space. The species showed high genetic diversity and moderate differentiation for which topography, progressive range contraction through the species' history and long-term persistence in stable climatic refugia are likely responsible. A strong geographic component was revealed among five genetic clusters that are connected with very limited gene flow. The environmental variables were a significant factor in the spatial genetic structure. Modeling results indicated that future reduction of the species range may affect its survival. The possible impact of climate changes and high need of in situ conservation are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aesculus / genetics*
  • Aesculus / physiology
  • Bayes Theorem
  • Climate Change
  • DNA, Plant / genetics
  • DNA, Plant / isolation & purification
  • DNA, Plant / metabolism
  • Ecosystem
  • Gene Flow
  • Genetic Variation*
  • Genetics, Population
  • Genotype
  • Greece
  • Microsatellite Repeats
  • Phylogeography
  • Refugium

Substances

  • DNA, Plant

Associated data

  • figshare/10.6084/m9.figshare.11183882

Grant support

This work was supported by Grant number 2017/27/N/NZ8/02781 to ŁW, Polish National Science Centre, https://ncn.gov.pl/?language=en. This study was partly financed by the statutory works of the Institute of Dendrology Polish Academy of Sciences, Faculty of Biological Sciences University of Zielona Góra and Faculty of Forestry Poznań University of Life Sciences. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.