Barley landraces are characterized by geographically heterogeneous genomic origins.
Barley landraces are characterized by geographically heterogeneous genomic origins.
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DOI：
10.1186/s13059-015-0712-3
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发表时间：
2015-08-21
期刊：
影响因子：
12.3
通讯作者：
Morrell PL
中科院分区：
文献类型：
--
作者：
Poets AM;Fang Z;Clegg MT;Morrell PL
驯化植物的遗传起源和它们在史前传播的沿着路线一直是争论的焦点。这场辩论的大部分集中在确定个别作物的起源中心。然而，许多重要的作物显示出明显的多重驯化的遗传特征，与地理上限定的起源中心不一致。为了更好地了解野生群体对驯化大麦的遗传贡献，我们比较了803个大麦地方品种和277个野生群体的单核苷酸多态性。我们发现单个野生种群的遗传贡献在整个基因组中是不同的。尽管广泛的人类运动和混合物的大麦地方品种驯化以来，个别地方品种的基因组表明一种模式的共同祖先与地理上接近的野生大麦种群。这导致地方品种具有来自多个来源群体的祖先马赛克，而不是离散的起源中心。我们排除了最近的基因渗入，这表明这些贡献是古老的。来自当地野生种群的基因组片段在地方品种中的过度表达表明，野生种群对原始品种的本地适应性变异做出了贡献。这项研究增加了我们对从野生大麦到驯化大麦的进化过程的理解。我们的研究结果表明，栽培大麦是由多个来源的人口与不平等的贡献可追溯到整个基因组。我们检测假定的适应性变异，并确定野生祖先赋予这些变异。本文的在线版本（doi：10.1186/s13059-015-0712-3）包含补充材料，可供授权用户使用。
The genetic provenance of domesticated plants and the routes along which they were disseminated in prehistory have been a long-standing source of debate. Much of this debate has focused on identifying centers of origins for individual crops. However, many important crops show clear genetic signatures of multiple domestications, inconsistent with geographically circumscribed centers of origin. To better understand the genetic contributions of wild populations to domesticated barley, we compare single nucleotide polymorphism frequencies from 803 barley landraces to 277 accessions from wild populations. We find that the genetic contribution of individual wild populations differs across the genome. Despite extensive human movement and admixture of barley landraces since domestication, individual landrace genomes indicate a pattern of shared ancestry with geographically proximate wild barley populations. This results in landraces with a mosaic of ancestry from multiple source populations rather than discrete centers of origin. We rule out recent introgression, suggesting that these contributions are ancient. The over-representation in landraces of genomic segments from local wild populations suggests that wild populations contributed locally adaptive variation to primitive varieties. This study increases our understanding of the evolutionary process associated with the transition from wild to domesticated barley. Our findings indicate that cultivated barley is comprised of multiple source populations with unequal contributions traceable across the genome. We detect putative adaptive variants and identify the wild progenitor conferring those variants. The online version of this article (doi:10.1186/s13059-015-0712-3) contains supplementary material, which is available to authorized users.