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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紫花苜蓿气候适应和对气候变化的适应力的进化基因组学


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力学并揭示气候适应的变化，可以使气候适应型作物的培育能够应对未来的气候变化。紫花苜蓿 （ subsp. ） 是牧草女王，在各种全球环境中表现出非凡的适应性，使其成为研究物种对气候变化反应的优秀模型。在这项研究中，我们使用来自 24 个种质的 702 个种质的基因组重测序数据进行了种群基因组分析，以揭示紫花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有助于紫花苜蓿的基因库，特别是丰富了防御和胁迫反应基因。亚种 （subsp. ） 与紫花苜蓿之间的亚种间渗入不仅有助于紫花苜蓿的气候适应，而且还引入了遗传负担。共有 1671 个基因与气候适应有关，其中 5.7% 是亚种的渗入。通过整合气候相关变体和气候数据，我们确定了易受未来气候变化影响的人群，尤其是在北半球的高纬度地区。这些发现为有针对性的保护计划和育种工作吹响了号角。我们还确定了表现出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紫花苜蓿当地适应机制的理解，并促进了气候适应性紫花苜蓿品种的育种，有助于应对未来气候变化的有效农业战略。