Strength in numbers? Cytotype frequency mediates effect of reproductive barriers in mixed-ploidy arrays.
When differentiated lineages come into contact, their fates depend on demographic and reproductive factors. These factors have been well-studied in taxa of the same ploidy, but less is known about sympatric lineages that differ in ploidy, particularly with respect to demographic factors. We assessed...
| Main Authors: | , , |
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| Format: | Dataset |
| Language: | unknown |
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2020
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| Online Access: | https://zenodo.org/record/3986868 https://doi.org/10.5061/dryad.1c59zw3sq |
| Summary: | When differentiated lineages come into contact, their fates depend on demographic and reproductive factors. These factors have been well-studied in taxa of the same ploidy, but less is known about sympatric lineages that differ in ploidy, particularly with respect to demographic factors. We assessed prezygotic, postzygotic, and total reproductive isolation in naturally-pollinated arrays of diploid-tetraploid and tetraploid-hexaploid population mixes of Campanula rotundifolia by measuring pollinator transitions, seed yield, germination rate, and proportion of hybrid offspring. Four frequencies of each cytotype were tested, and pollinators consistently overvisited rare cytotypes. Seed yield and F1 hybrid production were greater in 4X-6X arrays than 2X-4X arrays, while germination rates were similar, creating two distinct patterns of reproductive isolation. In 2X-4X arrays, postzygotic isolation was near-complete (3% hybrid offspring), and prezygotic isolation associated with pollinator preference is expected to facilitate the persistence of minority cytotypes. However, in 4X-6X arrays where postzygotic isolation permitted hybrid formation (44% hybrids), pollinator behavior drove patterns of reproductive isolation, with rare cytotypes being more isolated and greater gene flow expected from rare into common cytotypes. In polyploid complexes, both the specific cytotypes in contact and local cytotype frequency, likely reflecting spatial demography, will influence likelihood of gene exchange. Missing values are recorded as "." Tabs containing encoded information (i.e. weather type, insect type, population, etc) is included in each Excel file as relevant. Funding provided by: National Science FoundationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000001Award Number: DEB-1457686Funding provided by: National Science FoundationCrossref Funder Registry ID: http://dx.doi.org/10.13039/100000001Award Number: DBI-1461169 Pollinator visitation observations were made visually and were collected by hand on paper ... |
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