Data from: 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.

多年生向日葵属物种菊芋（Helianthus tuberosus），俗称洋姜（Jerusalem Artichoke）、太阳芋（Sunchoke），早在欧洲殖民者抵达北美东部前便已被种植。正因如此，它是该区域为数不多可佐证独立驯化起源的类群之一。17世纪早期该物种被引入旧大陆后，其块茎被用作食物与饲料来源，且至今仍被广泛利用。尽管这一块茎作物兼具文化与经济价值，但其起源仍存在诸多争议。目前存在多种相互对立的假说，这些假说围绕是否伴随杂交的多倍化事件展开，并将一年生向日葵普通向日葵（Helianthus annuus）以及5个亲缘关系较远的多年生向日葵物种列为潜在亲本。本研究通过对菊芋及其推定祖先类群的多样种群开展基因组浅层测序，对上述起源假说进行验证。研究利用完整质体基因组（plastome，151551 bp）、部分线粒体基因组（mitochondrial genome，196853 bp）以及35S（8196 bp）与5S（514 bp）核糖体DNA（ribosomal DNA），解析了向日葵属各类群间的系统发育关系。研究结果否定了菊芋起源于普通向日葵（Helianthus annuus）的可能性。此外，本研究首次提供遗传学证据，证明菊芋通过四倍体多毛向日葵与二倍体锯齿向日葵的杂交事件，多次独立起源于北美中东部的多年生向日葵类群。