Long-term climate change and periodic environmental extremes threaten food and fuel security¹ and global crop productivity^2,3,4. Although molecular and adaptive breeding strategies can buffer the effects of climatic stress and improve crop resilience⁵, these approaches require sufficient knowledge of the genes that underlie productivity and adaptation⁶—knowledge that has been limited to a small number of well-studied model systems. Here we present the assembly and annotation of the large and complex genome of the polyploid bioenergy crop switchgrass (Panicum virgatum). Analysis of biomass and survival among 732 resequenced genotypes, which were grown across 10 common gardens that span 1,800 km of latitude, jointly revealed extensive genomic evidence of climate adaptation. Climate–gene–biomass associations were abundant but varied considerably among deeply diverged gene pools. Furthermore, we found that gene flow accelerated climate adaptation during the postglacial colonization of northern habitats through introgression of alleles from a pre-adapted northern gene pool. The polyploid nature of switchgrass also enhanced adaptive potential through the fractionation of gene function, as there was an increased level of heritable genetic diversity on the nondominant subgenome. In addition to investigating patterns of climate adaptation, the genome resources and gene–trait associations developed here provide breeders with the necessary tools to increase switchgrass yield for the sustainable production of bioenergy.

长期的气候变化和周期性的极端环境事件威胁着粮食和燃料安全¹以及全球作物生产力^2,3,4。尽管分子和适应性育种策略可以缓冲气候压力的影响并提高作物的恢复力⁵，但这些方法需要对构成生产力和适应性⁶基础的基因有足够的了解——这些知识仅限于少数经过充分研究的模型系统。在这里，我们展示了多倍体生物能源作物柳枝稷 ( Panicum virgatum ) 的大型复杂基因组的组装和注释). 对横跨 1,800 公里纬度的 10 个普通花园种植的 732 个重测序基因型的生物量和存活率的分析共同揭示了气候适应的广泛基因组证据。气候-基因-生物量关联很丰富，但在差异很大的基因库中差异很大。此外，我们发现，基因流通过预适应的北方基因库中的等位基因渗入，在北方栖息地的后冰期殖民化期间加速了气候适应。柳枝稷的多倍体性质还通过基因功能的分离增强了适应性潜力，因为非显性亚基因组的可遗传遗传多样性水平有所提高。除了研究气候适应模式外，