Abstract
Summary
1. 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 analyzing gene flow and genetic structure within and among populations of the euglossine bee-pollinated vine Dalechampia scandens.
2. Using microsatellite markers, we assessed historical gene flow by quantifying regional-scale genetic structure and isolation by distance among 18 populations, and contemporary gene flow by estimating 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.
3. Gene flow was limited to certain nearby populations within continuous forest blocks, while 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.
4. 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.
1. 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 analyzing gene flow and genetic structure within and among populations of the euglossine bee-pollinated vine Dalechampia scandens.
2. Using microsatellite markers, we assessed historical gene flow by quantifying regional-scale genetic structure and isolation by distance among 18 populations, and contemporary gene flow by estimating 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.
3. Gene flow was limited to certain nearby populations within continuous forest blocks, while 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.
4. 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.
| Original language | English |
|---|---|
| Pages (from-to) | 1898-1908 |
| Journal | New Phytologist |
| Volume | 213 |
| Issue number | 4 |
| Early online date | 20 Dec 2016 |
| DOIs | |
| Publication status | Published - Mar 2017 |
Keywords
- Dalechampia
- Euglossini
- orchid bees
- paternity analysis
- plant-pollinator interactions
- spatial genetic structure