VCF files of common grassland plants from wild collected seeds of 19 common European grassland species with up to 4 consecutive generations grown in monoculture for seed production for restoration

A growing number of restoration projects require large amounts of seeds.
As harvesting natural populations cannot cover the demand, wild plants are
often propagated in large-scale monocultures. There are concerns that this
cultivation process may cause genetic drift and unintended selection,
which would alter the genetic properties of the cultivated populations and
reduce their genetic diversity. Such changes could reduce the pre-existing
adaptation of restored populations, and limit their adaptability to
environmental change. We used single nucleotide polymorphism (SNP) markers
and a pool-sequencing approach to test for genetic differentiation and
changes in gene diversity during cultivation in 19 wild grassland species,
comparing the source populations and up to four consecutive cultivation
generations. We then linked the magnitudes of genetic changes to the
species’ breeding systems and seed dormancy, to understand the roles of
these traits in genetic change. The propagation changed the genetic
composition of the cultivated generations only moderately. The genetic
differentiation we observed as a consequence of cultivation was much lower
than the natural genetic differentiation between different source regions.
The propagated generations harbored even higher gene diversity than
wild-collected seeds. Genetic change was stronger in self-compatible than
in self-incompatible species, probably as a result of increased
outcrossing in the monocultures. Synthesis and applications: Our study
indicates that large-scale seed production maintains the genetic integrity
of natural populations. Increased genetic diversity may be indicative of
increased adaptive potential of propagated seeds, which would make them
especially suitable for ecological restoration. Yet, it remains to be
tested whether these patterns observed on the level of molecular markers
will be mirrored also in plant phenotypes. Further, we used seeds produced
in Germany and Austria, where the seed production is regulated and
certified. Whether other seed production systems perform equally well
remains to be tested.