Genome skimming reveals the origin of the Jerusalem Artichoke tuber crop species: neither from Jerusalem nor an artichoke.
The perennial sunflower Helianthus tuberosus, known as Jerusalem Artichoke or Sunchoke, was cultivated in eastern North America before European contact. As such, it represents one of the few taxa that can support an independent origin of domestication in this region. Its tubers were adopted as a source of food and forage when the species was transferred to the Old World in the early 1600s, and are still used today. Despite the cultural and economic importance of this tuber crop species, its origin is debated. Competing hypotheses implicate the occurrence of polyploidization with or without hybridization, and list the annual sunflower H. annuus and five distantly related perennial sunflower species as potential parents. Here, we test these scenarios by skimming the genomes of diverse populations of Jerusalem Artichoke and its putative progenitors. We identify relationships among Helianthus taxa using complete plastomes (151 551 bp), partial mitochondrial genomes (196 853 bp) and 35S (8196 bp) and 5S (514 bp) ribosomal DNA. Our results refute the possibility that Jerusalem Artichoke is of H. annuus ancestry. We provide the first genetic evidence that this species originated recursively from perennial sunflowers of central-eastern North America via hybridization between tetraploid Hairy Sunflower and diploid Sawtooth Sunflower.
Biodiversity Research Centre and Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Dan G
DG
Bock
Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, 80309, USA.
Nolan C
NC
Kane
Biodiversity Research Centre and Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
Daniel P
DP
Ebert
Biodiversity Research Centre and Department of Botany, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.|Biology Department, Indiana University, Bloomington, IN, 47405, USA.
Loren H
LH
Rieseberg
D005075:Biological Evolution; D018556:Crops, Agricultural / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics; D018745:Genome, Plant / Q000235:genetics*; D005843:Geography; D006239:Haplotypes / Q000235:genetics; D006368:Helianthus / Q000235:genetics*; D016013:Likelihood Functions; D010802:Phylogeny; D035281:Plant Tubers / Q000235:genetics*; D011110:Polymorphism, Genetic
D004275:DNA, Ribosomal
allopolyploid speciation; phylogenomics; polyploid parentage; polyploidy; ultra-barcoding