Weedy rice (Oryza spp.) is a worldwide weed of domesticated rice (O. sativa), considered particularly problematic due to its strong competition with the crop, which leads to reduction in yields and harvest quality. Several studies have established multiple independent origins for weedy rice populations in the United States and various parts of Asia; however, the origins of weedy rice in South America have not been examined in a global context. We evaluated the genetic variation of weedy rice populations in Colombia, as well as the contributions of local wild Oryza species, local cultivated varieties, and exotic Oryza groups to the weed, using polymorphism generated by genotyping by sequencing (GBS). We found no evidence for genomic contributions from local wild Oryza species (O. glumaepatula, O. grandiglumis, O. latifolia, and O. alta) to Colombian weedy rice. Instead, Colombian weedy rice has evolved from local indica cultivars and has also likely been inadvertently imported as an exotic pest from the United States. Additionally, weeds comprising de novo admixture between these distinct weedy populations now represent a large proportion of genomic backgrounds in Colombian weedy rice. Our results underscore the impressive ability of weedy rice to evolve through multiple evolutionary pathways, including in situ de‐domestication, range expansion, and hybridization.

中文翻译：

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一些旧的东西，一些新的东西：哥伦比亚杂草稻（Oryza spp.）通过从头去驯化、外来基因流动和杂交的进化。


杂草稻 ( Oryza spp.) 是一种世界性的驯化稻 ( O. sativa ) 杂草，由于与作物的激烈竞争而被认为特别成问题，导致产量和收获质量下降。多项研究已确定美国和亚洲各地杂草稻种群的多个独立起源；然而，南美洲杂草稻的起源尚未在全球背景下进行研究。我们利用测序基因分型（GBS）产生的多态性评估了哥伦比亚杂草稻种群的遗传变异，以及当地野生稻物种、当地栽培品种和外来稻群体对杂草的贡献。我们没有发现任何证据表明当地野生稻种（ O. glumaepatula 、 O. grandiglumis 、 O. latifolia和O. alta ）对哥伦比亚杂草稻的基因组贡献。相反，哥伦比亚杂草稻是从当地的籼稻品种进化而来的，并且也可能无意中作为外来害虫从美国进口。此外，这些不同杂草种群之间从头混合的杂草现在代表了哥伦比亚杂草水稻基因组背景的很大一部分。我们的结果强调了杂草稻通过多种进化途径进化的令人印象深刻的能力，包括原位去驯化、范围扩大和杂交。