SummaryAegilops umbellulata serve as an important reservoir for novel biotic and abiotic stress tolerance for wheat improvement. However, chromosomal rearrangements and evolutionary trajectory of this species remain to be elucidated. Here, we present a comprehensive investigation into Ae. umbellulata genome by generating a high‐quality near telomere‐to‐telomere genome assembly of PI 554389 and resequencing 20 additional Ae. umbellulata genomes representing diverse geographical and phenotypic variations. Our analysis unveils complex chromosomal rearrangements, most prominently in 4U and 6U chromosomes, delineating a distinct evolutionary trajectory of Ae. umbellulata from wheat and its relatives. Furthermore, our data rectified the erroneous naming of chromosomes 4U and 6U in the past and highlighted multiple major evolutionary events that led to the present‐day U‐genome. Resequencing of diverse Ae. umbellulata accessions revealed high genetic diversity within the species, partitioning into three distinct evolutionary sub‐populations and supported by extensive phenotypic variability in resistance against several races/pathotypes of five major wheat diseases. Disease evaluations indicated the presence of several novel resistance genes in the resequenced lines for future studies. Resequencing also resulted in the identification of six new haplotypes for Lr9, the first resistance gene cloned from Ae. umbellulata. The extensive genomic and phenotypic resources presented in this study will expedite the future genetic exploration of Ae. umbellulata, facilitating efforts aimed at enhancing resiliency and productivity in wheat.

中文翻译：

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伞形山羊草的基因组为小麦改良的 U 基因组中独特的结构变异和遗传多样性提供了新的见解


摘要伞山羊草是小麦改良中新型生物和非生物胁迫耐受性的重要储存库。然而，该物种的染色体重排和进化轨迹仍有待阐明。在这里，我们对 Ae 进行了全面的调查。 umbellulata 基因组通过生成 PI 554389 的高质量近端粒到端粒基因组组装并对 20 个额外的 Ae 进行重新测序。 umbellulata 基因组代表不同的地理和表型变异。我们的分析揭示了复杂的染色体重排，最显着的是 4U 和 6U 染色体，描绘了 Ae 独特的进化轨迹。 umbellulata 来自小麦及其近亲。此外，我们的数据纠正了过去 4U 和 6U 染色体的错误命名，并强调了导致当今 U 基因组的多个主要进化事件。不同 Ae 的重测序。 umbellulata 种质显示出该物种内的高度遗传多样性，分为三个不同的进化亚群，并得到对五种主要小麦病害的几个种族/致病型的广泛表型变异性的支持。疾病评估表明，在用于未来研究的重新测序品系中存在几种新的抗性基因。重新测序还鉴定出了 Lr9 的六种新单倍型，Lr9 是从伊蚊中克隆的第一个抗性基因。伞形花序。这项研究中提供的广泛的基因组和表型资源将加速伊蚊未来的遗传探索。 umbellulata，促进旨在提高小麦弹性和生产力的努力。