Anthropogenic and natural drivers of gene flow in a temperate wild fruit tree: a basis for conservation and breeding programs in apples.
Gene flow is an essential component of population adaptation and species evolution. Understanding of the natural and anthropogenic factors affecting gene flow is also critical for the development of appropriate management, breeding, and conservation programs. Here, we explored the natural and anthropogenic factors impacting crop-to-wild and within wild gene flow in apples in Europe using an unprecedented dense sampling of 1889 wild apple (Malus sylvestris) from European forests and 339 apple cultivars (Malus domestica). We made use of genetic, environmental, and ecological data (microsatellite markers, apple production across landscapes and records of apple flower visitors, respectively). We provide the first evidence that both human activities, through apple production, and human disturbance, through modifications of apple flower visitor diversity, have had a significant impact on crop-to-wild interspecific introgression rates. Our analysis also revealed the impact of previous natural climate change on historical gene flow in the nonintrogressed wild apple M. sylvestris, by identifying five distinct genetic groups in Europe and a north-south gradient of genetic diversity. These findings identify human activities and climate as key drivers of gene flow in a wild temperate fruit tree and provide a practical basis for conservation, agroforestry, and breeding programs for apples in Europe.
Ecologie, Systématique et Evolution, Université Paris-Sud Orsay, France ; CNRS Orsay, France ; Department of Plant Ecology and Evolution, Uppsala University Uppsala, Sweden.
Amandine
A
Cornille
Ecologie, Systématique et Evolution, Université Paris-Sud Orsay, France ; CNRS Orsay, France.
Alice
A
Feurtey
Département de biologie, Université de Sherbrooke Sherbrooke, QC, Canada.
Uriel
U
Gélin
Ecologie, Systématique et Evolution, Université Paris-Sud Orsay, France ; CNRS Orsay, France.
Jeanne
J
Ropars
Institute for Forestry and Game Management Geraardsbergen, Belgium.
Kristine
K
Misvanderbrugge
Ecologie, Systématique et Evolution, Université Paris-Sud Orsay, France ; CNRS Orsay, France.
Pierre
P
Gladieux
Ecologie, Systématique et Evolution, Université Paris-Sud Orsay, France ; CNRS Orsay, France.
Tatiana
T
Giraud
SPIPOLL; admixture; crabapple; dispersal; glacial refugia; global changes; pollinators