Abstract Detail

Hybrids and Hybridization

Pham, Kasey [1], Jones, Rebecca [2], Gélinas-Marion, Ariane [2], Soltis, Douglas [3], Soltis, Pamela [4], Vaillancourt, René [2], Potts, Brad [2].

Mapping the Mosaic Genomes of Naturally Occurring Eucalyptus Hybrids.

Adaptive introgression, the transfer of useful alleles from one species to another through hybridization and backcrossing, is hypothesized to introduce new genetic diversity which could help plants expand into new habitats and respond to environmental change. With the increasing awareness that hybridization is common across the plant tree of life, major questions have arisen, including which regions and genes of the genome are most likely to be exchanged between species, and how do these affect the species' evolution? However, there is still little that is known about the genomic distribution and content of introgressed regions outside of a few model systems. In this study, we aimed to determine the effects of hybridization on Eucalyptus globulus by characterizing introgressed genomic regions donated from a rare endemic species, Eucalyptus cordata. Previous work has shown that morphologically typical E. globulus trees growing in close proximity to several of the small populations of E. cordata have captured chloroplast DNA and some nuclear markers from E. cordata. It is possible that these alleles have been retained for over 17,000 years because they have conferred an advantage for the introgressant Eucalyptus trees. In a first step to testing the adaptive value of hybridization in this system, we use whole-genome resequencing and admixture analysis to map the mosaic nature of the E. globulus genome. With that information, we address the following questions: 1) which genomic regions and genes are most likely to be introgressed and 2) to what extent does selection, positive or negative, play a role in introgression?

1 - University of Florida, Biology, 220 Bartram Hall, Gainesville, FL, 32611-8525, USA
2 - University of Tasmania, Biological Sciences, Private Bag 55, Hobart, TAS, 7001, Australia
3 - University Of Florida, Florida Museum Of Natural History, Dickinson Hall, Gainesville, FL, 32611, United States
4 - University Of Florida, Florida Museum Of Natural History, Gainesville, FL, 32611.0, United States

Keywords:
introgression
genome resequencing
population genomics
Myrtaceae
admixture.

Presentation Type: Oral Paper
Number: HH1001
Abstract ID:455
Candidate for Awards:Margaret Menzel Award