Hoyos Verónica, Plaza Guido, Li Xiang, Caicedo Ana L
Departamento de Agronomía Universidad Nacional de Colombia Bogotá Colombia.
Plant Biology Graduate Program University of Massachusetts Amherst MA USA.
Evol Appl. 2020 Apr 9;13(8):1968-1983. doi: 10.1111/eva.12955. eCollection 2020 Sep.
Weedy rice ( spp.) is a worldwide weed of domesticated rice (), 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 species, local cultivated varieties, and exotic groups to the weed, using polymorphism generated by genotyping by sequencing (GBS). We found no evidence for genomic contributions from local wild species (, , and ) to Colombian weedy rice. Instead, Colombian weedy rice has evolved from local 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.
杂草稻（Oryza spp.）是栽培稻（Oryza sativa）在全球范围内的杂草，因其与作物的激烈竞争而被认为是特别棘手的问题，这种竞争会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的杂草稻种群有多个独立起源；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，以及当地野生稻种、当地栽培品种和外来稻种群体对这种杂草的贡献。我们没有发现当地野生稻种（Oryza glumaepatula、Oryza barthii、Oryza meridionalis和Oryza nivara）对哥伦比亚杂草稻有基因组贡献的证据。相反，哥伦比亚杂草稻是由当地栽培品种进化而来的，也可能是作为外来有害生物从美国意外引入的。此外，由这些不同杂草种群之间的新生混合体组成的杂草，现在在哥伦比亚杂草稻的基因组背景中占很大比例。我们的结果强调了杂草稻通过多种进化途径进化的惊人能力，包括就地去驯化、范围扩展和杂交。
