Crop diversity underpins the productivity, resilience and adaptive capacity of agriculture. Loss of this diversity, termed crop genetic erosion, is therefore concerning. While alarms regarding evident declines in crop diversity have been raised for over a century, the magnitude, trajectory, drivers and significance of these losses remain insufficiently understood. We outline the various definitions, measurements, scales and sources of information on crop genetic erosion. We then provide a synthesis of evidence regarding changes in the diversity of traditional crop landraces on farms, modern crop cultivars in agriculture, crop wild relatives in their natural habitats and crop genetic resources held in conservation repositories. This evidence indicates that marked losses, but also maintenance and increases in diversity, have occurred in all these contexts, the extent depending on species, taxonomic and geographic scale, and region, as well as analytical approach. We discuss steps needed to further advance knowledge around the agricultural and societal significance, as well as conservation implications, of crop genetic erosion. Finally, we propose actions to mitigate, stem and reverse further losses of crop diversity.

中文翻译：

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作物遗传侵蚀：理解和应对作物多样性的丧失

作物多样性是农业生产力、复原力和适应能力的基础。因此，这种多样性的丧失（称为作物遗传侵蚀）令人担忧。尽管关于作物多样性明显下降的警报已经提出了一个多世纪，但对这些损失的幅度、轨迹、驱动因素和意义仍然知之甚少。我们概述了有关作物遗传侵蚀的各种定义、测量、规模和信息来源。然后，我们提供了关于农场传统作物地方品种、农业现代作物品种、自然栖息地中的作物野生近缘种以及保存在保存库中的作物遗传资源多样性变化的综合证据。这一证据表明，显着的损失，以及多样性的维持和增加，在所有这些情况下都发生过，其程度取决于物种、分类和地理规模、区域以及分析方法。我们讨论了进一步推进有关作物遗传侵蚀的农业和社会意义以及保护意义的知识所需的步骤。最后，我们提出了减轻、阻止和扭转作物多样性进一步丧失的行动。