背景回顾：Sorghum is a drought-tolerant staple crop for half a billion people in Africa and Asia, an important source of animal feed throughout the world and a biofuel feedstock of growing importance. Cultivated sorghum and its inter-fertile wild relatives constitute the primary gene pool for sorghum. 

研究意义：Understanding and characterizing the diversity within this valuable resource is fundamental for its effective utilization in crop improvement.

主要研究：Here, we report analysis of a sorghum pan-genome to explore genetic diversity within the sorghum primary gene pool. 

结果1-13个基因组的组装：We assembled 13 genomes representing cultivated sorghum and its wild relatives, and integrated them with 3 other published genomes to generate a pan-genome of 44,079 gene families with 222.6 Mb of new sequence identified. 

结果2-PAV鉴定：The pan-genome displays substantial gene-content variation, with 64% of gene families showing presence/absence variation among genomes. 

结果3-核心基因与非必需基因比较：Comparisons between core genes and dispensable genes suggest that dispensable genes are important for sorghum adaptation. 

结果4-遗传变异分布及影响因素：Extensive genetic variation was uncovered within the pan-genome, and the distribution of these variations was influenced by variation of recombination rate and transposable element content across the genome. 

结果5-PAV受到驯化选择：We identified presence/absence variants that were under selectionduring sorghum domestication and improvement, and demonstrated that such variation had important phenotypic outcomes that could contribute to crop improvement. 

结论：The constructed sorghum pan-genome represents an important resource for sorghum improvement and gene discovery.

 摘 要 

高粱是非洲和亚洲约5亿人口的耐旱粮食作物，同时也是全球动物饲料的重要来源，以及日益重要的生物燃料原料。栽培种高粱及可与其杂交的野生近缘种构成了高粱的主要基因库。了解并鉴定这一宝贵资源的多样性是有效利用这一资源进行作物改良的基础。本文中，作者进行了高粱泛基因组的分析，以探索高粱主要基因库中的遗传多样性。作者对栽培种高粱及其野生近缘种的13个代表种进行了基因组的组装，并将它们与其他3个已发表的基因组整合，获得了一个包含44079个基因家族的泛基因组，其中222.6 Mb的序列为新鉴定的序列。泛基因组表现出显著的基因含量变异，64%的基因家族存在基因组间的存在/缺失变异（PAV）。核心基因与非必需基因的比较表明，非必需基因对高粱的适应性具有重要作用。作者在泛基因组中发现了广泛的遗传变异，这些变异的分布受基因组上重组率和转座因子含量的影响。作者鉴定了高粱驯化和改良过程中的PAV，并证明这种变异作用于某些重要的表型，有助于作物改良。本研究所构建的高粱泛基因组是高粱改良和基因发现的重要资源。