Data from: Hidden founder effects: small-scale spatial genetic structure in recently established populations of the grassland specialist plant Anthyllis vulneraria

The long-term establishment success of founder plant populations has been
commonly assessed based on the measures of population genetic diversity
and among population genetic differentiation, with founder populations
expected to carry sufficient genetic diversity when population
establishment is the result of many colonists from multiple source
populations (the ‘migrant pool’ colonization model). Theory, however,
predicts that, after initial colonization, rapid population expansion may
result in a fast increase in the extent of spatial genetic structure
(SGS), independent of extant genetic diversity. This SGS can reduce
long-term population viability by increasing inbreeding. Using 12
microsatellite markers, we inferred colonization patterns in four recent
populations of the grassland specialist plant Anthyllis vulneraria and
compared the extent of SGS between recently established and old
populations. Assignment analyses of the individuals of recent population
based on the genetic composition of nine adjacent putative source
populations suggested the occurrence of the ‘migrant pool’ colonization
model, further confirmed by high genetic diversity within and low genetic
differentiation among recent populations. Population establishment,
however, resulted in the build-up of strong SGS, most likely as a result
of spatially restricted recruitment of the progeny of initial colonists.
Although reduced, significant SGS was nonetheless observed to persist in
old populations. The presence of SGS was in all populations associated
with elevated inbreeding coefficients, potentially affecting the long-term
viability of these populations. In conclusion, this study illustrates the
importance of studying SGS next to population genetic diversity and
differentiation to adequately infer colonization patterns and long-term
establishment success of plant species.