Abstract Detail

Recent Topics Posters

Gaynor, Michelle [1], Marchant, D. Blaine [2], Soltis, Douglas E. [3], Soltis, Pamela S. [3].

Absence of clear niche divergence among ploidal levels in a classic autopolyploid system, Galax urceolata (Diapensiaceae).

Autopolyploidy, or the process of whole-genome duplication within a species, leads to two closely related cytotypes in one geographic location. The process by which autopolyploids become established was hypothesized to be facilitated by ecological niche divergence from the diploid progenitor.  Here we tested this hypothesis in diploid, triploid, and tetraploid Galax urceolata (Diapensiaceae).  In addition, we determined the effects of projected climate change on the relative distribution of these three cytotypes in the next 50 years. We investigated whether abiotic niche divergence has shaped the current distribution of diploid, triploid, and tetraploid Galax urceolata in eastern North America. We employed ecological niche modeling and multivariate analyses of environmental space, in addition to geographic range analyses. With these results, we projected the future ranges of these three cytotypes to determine how they will be altered by 2070 with climate change. We identified that diploids, triploids, and tetraploids share climatic niche spaces and are geographically sympatric. The absence of climatic niche divergence between these cytotypes is best explained by genetic clustering within ecoregions between both diploid and polyploid populations, possibly due to multiple polyploid origin events, local adaptation, and reduced sexual reproduction. Lack of niche variation and broad sympatry among cytotypes suggest that triploid and tetraploid G. urceolata may not be broadly dispersing, but instead are recurrently produced among diploid populations. Climate projections for G. urceolata showed substantial range contraction without much, or any, range shift of all three cytotypes, suggesting that this species will likely go extinct in the wild as the available mountain refugia become warmer and drier. Finally, the drastic decreases in range distributions of all three cytotypes based on climate change models indicate that G. urceolata may be doomed in their natural habitat and should be conserved.

1 - University of Central Florida, Department of Biology , 4110 Libra Drive, Orlando, Fl, 32816, USA
2 - University of Florida, Florida Museum of Natural History, Gainesville, FL, 32611, USA
3 - University Of Florida, Florida Museum Of Natural History, PO BOX 117800, Gainesville, FL, 32611-7800, USA, 352/273-1964

Keywords:
Autopolyploidy
Polyploidy
ecological niche models.

Presentation Type: Recent Topics Poster
Session: P, Recent Topics Posters
Location: Exhibit Hall/Omni Hotel
Date: Monday, June 26th, 2017
Time: 5:30 PM
Number: PRT010
Abstract ID:753
Candidate for Awards:None