Given the escalating impact of climate change on agriculture and food security, gaining insights into the evolutionary dynamics of climatic adaptation and uncovering climate-adapted variation can empower the breeding of climate-resilient crops to face future climate change. Alfalfa ( subsp. ), the queen of forages, shows remarkable adaptability across diverse global environments, making it an excellent model for investigating species responses to climate change. In this study, we performed population genomic analyses using genome resequencing data from 702 accessions of 24 to unravel alfalfa’s climatic adaptation and genetic susceptibility to future climate change. We found that interspecific genetic exchange has contributed to the gene pool of alfalfa, particularly enriching defense and stress-response genes. Intersubspecific introgression between subsp (subsp. ) and alfalfa not only aids alfalfa’s climatic adaptation but also introduces genetic burden. A total of 1671 genes were associated with climatic adaptation, and 5.7% of them were introgressions from subsp. . By integrating climate-associated variants and climate data, we identified populations that are vulnerable to future climate change, particularly in higher latitudes of the Northern Hemisphere. These findings serve as a clarion call for targeted conservation initiatives and breeding efforts. We also identified pre-adaptive populations that demonstrate heightened resilience to climate fluctuations, illuminating a pathway for future breeding strategies. Collectively, this study enhances our understanding about the local adaptation mechanisms of alfalfa and facilitates the breeding of climate-resilient alfalfa cultivars, contributing to effective agricultural strategies for facing future climate change.

中文翻译：

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苜蓿气候适应和气候变化恢复力的进化基因组学


鉴于气候变化对农业和粮食安全的影响不断升级，深入了解气候适应的进化动态并发现适应气候的变异可以使培育气候适应型作物以应对未来的气候变化。紫花苜蓿（subsp.），牧草之王，在不同的全球环境中表现出卓越的适应性，使其成为研究物种对气候变化反应的绝佳模型。在这项研究中，我们利用 24 个品种中的 702 个种质的基因组重测序数据进行了群体基因组分析，以揭示苜蓿的气候适应和对未来气候变化的遗传易感性。我们发现，种间遗传交换对苜蓿的基因库做出了贡献，特别是丰富了防御和应激反应基因。亚种（subsp.）和苜蓿之间的亚种间渗入不仅有助于苜蓿的气候适应，而且还带来了遗传负担。共有1671个基因与气候适应相关，其中5.7%是来自亚种的基因渗入。 。通过整合与气候相关的变异和气候数据，我们确定了容易受到未来气候变化影响的人群，特别是在北半球高纬度地区。这些发现为有针对性的保护举措和育种工作敲响了号角。我们还确定了对气候波动具有更强适应能力的预适应种群，为未来的育种策略指明了道路。总的来说，这项研究增强了我们对苜蓿当地适应机制的了解，并促进了气候适应型苜蓿品种的选育，为应对未来气候变化的有效农业战略做出了贡献。