Data from: Euglossine bees mediate only limited long-distance gene flow in a tropical vine

Euglossine bees (Apidae: Euglossini) have long been hypothesized to act as
long-distance pollinators of many low-density tropical plants. We tested
this hypothesis by the analysis of gene flow and genetic structure within
and among populations of the euglossine bee-pollinated vine Dalechampia
scandens. Using microsatellite markers, we assessed historical gene flow
by the quantification of regional-scale genetic structure and isolation by
distance among 18 populations, and contemporary gene flow by the
estimation of recent migration rates among populations. To assess
bee-mediated pollen dispersal on a smaller scale, we conducted paternity
analyses within a focal population, and quantified within-population
spatial genetic structure in four populations. Gene flow was limited to
certain nearby populations within continuous forest blocks, whereas drift
appeared to dominate on larger scales. Limited long-distance gene flow was
supported by within-population patterns; gene flow was biased towards
nearby plants, and significant small-scale spatial genetic structure was
detected within populations. These findings suggest that, although female
euglossine bees might be effective at moving pollen within populations,
and perhaps within forest blocks, their contribution to gene flow on the
regional scale seems too limited to counteract genetic drift in patchily
distributed tropical plants. Among-population gene flow might have been
reduced following habitat fragmentation.