Variation in reproduction and gene flow between cytotypes in a polyploid complex: one size does not fit all ...

• Main Authors: Sutherland, Brittany, Galloway, Laura
• Format: Dataset
• Language: English
• Published: Dryad 2021
• Subjects: Evolutionary ecology; Canada; Campanula rotundifolia
• Online Access: https://dx.doi.org/10.5061/dryad.gqnk98smp; https://datadryad.org/stash/dataset/doi:10.5061/dryad.gqnk98smp

Whole-genome duplication is considered an important speciation mechanism in plants. However, its effect on reproductive isolation between higher cytotypes is not well understood. We used backcrosses between different ploidy levels and surveys of mixed-ploidy contact zones to determine how reproductive barriers differed with cytotype across a polyploid complex. We backcrossed F1 hybrids derived from 2X-4X and 4X-6X crosses in the Campanula rotundifolia autopolyploid complex, measured backcross fitness, and estimated backcross DNA cytotype. We then sampled four natural mixed-ploidy contact zones (two 2X-4X and two 4X-6X), estimated ploidy, and genotyped individuals across each contact zone. Reproductive success and capacity for gene flow was markedly lower for 2X-4X than 4X-6X hybrids. In fact, 3X hybrids could not backcross; all 2X-4X backcross progeny resulted from neotetraploid F1 hybrids. Further, no 3X individuals were found in 2X-4X contact zones, and 2X and 4X individuals were genetically distinct. By ... : The datasets attached are locations of individual plants in four mixed-ploidy populations in Germany, the Czech Republic, the United Kingdom, and Canada. Latitude and longitude were recorded for each plant using a degrees and decimal minutes system. Locations were then converted into a Cartesian coordinate system by calculating distance in meters from the southernmost plant and from the easternmost plant to establish Y-axis and X-axis coordinates, respectively. In no population was the same plant both the southernmost and westernmost. Leaf tissue from each plant was then collected and dried in silica gel. Genome content was estimated using flow cytometry, which was then compared to external standards to calculate estimated ploidy level. ...