Background Worldwide feralization of crop species into agricultural weeds threatens global food security. Weedy rice is a feral form of rice that infests paddies worldwide and aggressively outcompetes cultivated varieties. Despite increasing attention in recent years, a comprehensive understanding of the origins of weedy crop relatives and how a universal feralization process acts at the genomic and molecular level to allow the rapid adaptation to weediness are still yet to be explored. Results We use whole-genome sequencing to examine the origin and adaptation of 524 global weedy rice samples representing all major regions of rice cultivation. Weed populations have evolved multiple times from cultivated rice, and a strikingly high proportion of contemporary Asian weed strains can be traced to a few Green Revolution cultivars that were widely grown in the late twentieth century. Latin American weedy rice stands out in having originated through extensive hybridization. Selection scans indicate that most genomic regions underlying weedy adaptations do not overlap with domestication targets of selection, suggesting that feralization occurs largely through changes at loci unrelated to domestication. Conclusions This is the first investigation to provide detailed genomic characterizations of weedy rice on a global scale, and the results reveal diverse genetic mechanisms underlying worldwide convergent rice feralization.

中文翻译：

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不同的遗传机制是全球趋同水稻野化的基础

背景 世界范围内作物物种野化成农业杂草威胁着全球粮食安全。杂草稻是一种野生稻米，它侵染世界各地的稻田，并在与栽培品种的竞争中表现出色。尽管近年来受到越来越多的关注，但对杂草作物亲属的起源以及普遍的野化过程如何在基因组和分子水平上起作用以允许快速适应杂草的全面了解仍有待探索。结果我们使用全基因组测序来检查代表所有主要水稻种植区域的 524 个全球杂草水稻样本的起源和适应性。杂草种群从栽培水稻进化了多次，当代亚洲杂草品系的惊人比例可以追溯到 20 世纪后期广泛种植的少数绿色革命品种。拉丁美洲杂草稻在起源于广泛杂交方面脱颖而出。选择扫描表明，杂草适应基础的大多数基因组区域与选择的驯化目标不重叠，这表明野化主要通过与驯化无关的基因座的变化发生。结论 这是首次在全球范围内提供详细的杂草水稻基因组特征的研究，结果揭示了全球趋同性水稻野生化背后的多种遗传机制。选择扫描表明，杂草适应基础的大多数基因组区域与选择的驯化目标不重叠，这表明野化主要通过与驯化无关的基因座的变化发生。结论 这是首次在全球范围内提供详细的杂草水稻基因组特征的研究，结果揭示了全球趋同性水稻野生化背后的多种遗传机制。选择扫描表明，杂草适应基础的大多数基因组区域与选择的驯化目标不重叠，这表明野化主要通过与驯化无关的基因座的变化发生。结论 这是首次在全球范围内提供详细的杂草水稻基因组特征的研究，结果揭示了全球趋同性水稻野生化背后的多种遗传机制。