Create your own conference schedule! Click here for full instructions

Abstract Detail


Dillenberger, Markus S. [1], Liston, Aaron [2].

Origin of the decaploid Oregon endemic Fragaria cascadensis (Rosaceae).

The Cascade strawberry (Fragaria cascadensis) is a species newly described in 2012 that is endemic to the Cascade mountain range in Oregon, USA. Fragaria cascadensis is one of two naturally occurring decaploid strawberry species; the other is F. iturupensis, endemic to Iturup Island, in northeast Asia. The known distribution range spans 330km from north of Mt. Hood to south of Crater Lake National Park in montane habitats between 1000-1800m. The decaploid species occurs in sympatry with octoploid F. virginiana subsp. platypetala and diploid F. vesca subsp. bracteata. It has been suggested that F. cascadensis is a natural hybrid of the two sympatric species, based on ploidy level and morphology. Our goals are to identify the progenitors of F. cascadensis and to determine if there was a single or multiple origins. We collected 16 populations with 6 samples each of F. cascadensis covering the entire distribution range. The ploidy level of these samples was determined with flow cytometry. Chloroplast (cp) haplotypes were identified from a plastome phylogeny of Fragaria and assayed with restriction site analysis of diagnostic polymorphisms. Preliminary results show a more complex pattern than previously hypothesized for the origin of F. cascadensis. Most samples of F. cascadensis have a unique cp haplotype that is shared with some Oregon individuals of F. virginiana subsp. platypetala and F. ×ananassa subsp. cuneifolia (the naturally occurring hybrid of the octoploids F. chiloensis and F. virginiana subsp. platypetala). Approximately 30% of sampled F. cascadensis show the typical haplotype present in octoploid F. virginiana from across North America. Results of flow cytometry confirmed the existence of enneaploid (9x) individuals, especially where F. cascadensis (10x) and F. virginiana subsp. platypetala (8x) co-occur. The cp haplotype results and presence of 9x individuals could indicate recent exchange of genetic material via hybridization between the taxa. Alternatively, the cp haplotype distribution could reflect incomplete lineage sorting of ancient polymorphisms. To answer these and further questions we are using target capture sequencing of the nuclear genome, plus genome skimming for chloroplast and mitochondrial genomes, in 15 populations plus 6 additional individuals of other Fragaria species. With data spanning all three genomes, we aim to disentangle the complex evolutionary history of F. cascadensis, as well as provide a roadmap for similar studies of other high polyploids.

Log in to add this item to your schedule

1 - Oregon State University, Department of Boatny and Plant Pathology, 2082 Cordley Hall, Corvallis, OR, 97331, USA
2 - Oregon State University, Department Of Botany & Plant Pathology, 2082 Cordley Hall, Corvallis, OR, 97331-2902, USA

target capture sequencing
hybrid speciation.

Presentation Type: Oral Paper
Session: 29, Phylogenomics I
Location: Fort Worth Ballroom 4/Omni Hotel
Date: Tuesday, June 27th, 2017
Time: 2:00 PM
Number: 29003
Abstract ID:65
Candidate for Awards:None

Copyright © 2000-2017, Botanical Society of America. All rights reserved