Abstract Detail

Species tree reconstruction in polyploid complexes

Bock, Dan [1], Kane, Nolan [2], Ebert, Daniel [1], Rieseberg, Loren [1].

The origin of the Jerusalem artichoke: neither from Jerusalem nor an Artichoke.

The perennial sunflower Helianthus tuberosus, widely known as the Jerusalem artichoke or sunchoke, has been cultivated in Eastern North America since pre-Columbian times, and is considered one of the oldest North American crops. Its large tubers were readily adopted as a source of food and forage when the species was transferred to the Old World in the early 1600s, and are used today in human and livestock diets as well as biofuel production. Despite its cultural and economical importance, the origin of the Jerusalem artichoke is debated. Competing hypotheses on the formation of this hexaploid species implicate the occurrence of whole genome duplication with or without hybridization and list the annual sunflower H. annuus and five perennial sunflower species as potential parents. We test these scenarios by scanning the genomes of geographically diverse populations of eight sunflower species that include the Jerusalem artichoke and all its putative progenitors. We identify relationships among Helianthus taxa using data of unmatched scale for this group, consisting of complete plastid genomes (151,552 bp) and partial sequences for the mitochondrial genome (196,853 bp) and nuclear-encoded 35S and 5S ribosomal DNA (8,710 bp). Our results refute the possibility that Jerusalem artichoke is of H. annuus ancestry. Instead, we show that this species traces its origin exclusively from perennial sunflowers of Central-Eastern North America. Specifically, we provide evidence that the Jerusalem artichoke is an auto-allopolyploid formed via hybridization between autotetraploid hairy sunflower (H. hirsutus), the likely maternal parent, and diploid sawtooth sunflower (H. grosseserratus), the likely paternal parent.

Broader Impacts:

1 - University of British Columbia, Botany, 3529-6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
2 - University of Colorado, Boulder, UCB 334, Boulder, CO, 80309, USA

Keywords:
Helianthus tuberosus
genome skimming.

Presentation Type: Symposium or Colloquium Presentation
Session: SY09
Location: Grand Ballroom A/Riverside Hilton
Date: Wednesday, July 31st, 2013
Time: 10:45 AM
Number: SY09008
Abstract ID:411
Candidate for Awards:None