Data from: Crop-to-wild gene flow and spatial genetic structure in the closest wild relatives of the cultivated apple

Crop-to-wild gene flow have important evolutionary and ecological
consequences and require careful consideration in conservation programs
for wild genetic resources of potential use in breeding programs and in
assessments of the risk of transgene escape into natural ecosystems. Using
26 microsatellites and a set of 1181 trees, we investigated the extent of
introgression from the cultivated apple, Malus domestica, to its three
closest wild relatives, M. sylvestris in Europe, M. orientalis in the
Caucasus and M. sieversii in Central Asia. We found footprints of
introgression from M. domestica to M. orientalis (3.2% of hybrids), M.
sieversii (14.8%) and M. sylvestris (36.7%). Malus sieversii and M.
orientalis presented weak but significant genetic structures across their
geographic range. Malus orientalis displayed genetic differentiation with
three differentiated populations in Turkey, Armenia and Russia. Malus
sieversii consisted of a main population spread over Central Asia and a
smaller population in the Tian Shan Mountains. The low Sp values suggest
high dispersal capacities for the wild apple relatives. High potential for
crop-to-wild gene flow in apples needs to be considered in the
implementation of in situ and ex situ actions for the conservation of wild
apple genetic resources potentially useful to plant breeding.