HAPPAN : Haplotype and pan-genome exploration of the multiparental wild barley population HEB-25 to access its full potential for breeding improved barley cultivars better adapted to changing environments.

作物的野生近缘种是遗传多样性的重要来源，具有提高优良品种和确保粮食稳定生产的巨大潜力，然而，它们的基因库在很大程度上仍未被开发。大麦是德国和欧洲的主要作物，需要加快培育更能适应气候和环境变化的改良大麦品种的步伐。野生大麦遗传多样性是多亲本野生大麦群体HEB-25（“Halle Exotic barley”）的核心，该群体将25个野生大麦的特定染色体片段插入到优质大麦品种“Barke”（Hordeum vulgare L.）的基因组背景中。我们的目标是对25个野生大麦供体进行测序，以照亮第一个野生大麦泛基因组的地平线。随后，pan基因组数据将用于解码野生大麦巢式关联图谱（NAM）群体HEB-25的1420个系的整个群体。这将允许检测大序列变异并定义超高密度的全基因组DNA标记集，包括在驯化大麦系中未开发的新变异和基因。为了充分挖掘HEB-25群体的潜力，HAPPAN将首先构建一个野生大麦的基因组参考。由于大麦基因组大（5.1 Gbp）和高度重复序列（>80%），高质量参考基因的组装是一个巨大的挑战。通过对基因模型的预测和功能的标注，完成了野生大麦基因组资源的构建。完整的HEB-25群体将被评估以构建第一个野生大麦泛基因组。这将允许深入调用编码和调控区域的差异，以研究HEB-25系和现有驯化大麦品种之间的snp，存在/缺失和结构差异。通过这种全面的方法，HAPPAN有望揭示新的多样性等位基因，同时也能发现最有可能来自重复和亚功能化事件的新基因。HAPPAN将定义单倍型，并提供超高分辨率的DNA标记。随着各种野生大麦单倍型群体的定义，我们将进入一个基于单倍型分析的大麦育种和研究的新时代。自2014年以来，我们在区域和全球田间试验中连续分析了HEB-25群体的1420个NAM品系，以了解植物发育、产量形成、抗病性和抗逆性等重要农艺性状的变化。基于HAPPAN pan基因组数据，这一庞大的表型数据收集将被用于绘制并最终克隆控制所研究性状的致病基因。我们相信，这种新资源的准确性和精确性将大大加快培育更好地适应不断变化的环境的改良大麦品种的步伐。

Wild relatives of crops are an important source of genetic diversity with a high potential to enhance elite cultivars and ensure stable food production, however, their gene repertoire remains largely unexplored. Barley is a major crop in Germany and Europe and the pace to breed improved barley cultivars, which are better adapted to climatic and environmental changes is required to accelerate. The genetic diversity among wild barley accessions is a centerpiece of the multi-parental wild barley population HEB-25 ("Halle Exotic Barley"), which carries defined chromosomal segments from 25 wild barleys inserted into the genome background of the elite barley cultivar 'Barke' (Hordeum vulgare L.). We aim to sequence the 25 wild barley donor accessions to illuminate the horizon for a first wild barley pan-genome. Subsequently the pan genome data will be used to decode the entire population of 1,420 lines of the wild barley nested association mapping (NAM) population HEB-25. This will allow to detect large sequence variations and define an ultra-high density genome-wide set of DNA markers, including novel variations and genes that are untapped in domesticated barley lines. To exploit the full potential of the HEB-25 population, HAPPAN will first construct a genome reference for a wild barley. An assembly of a high-quality reference in barley is a grand challenge because of its large genome size (5.1 Gbp) and highly repetitive sequence (>80%). The wild barley genomic resource will be completed by prediction of gene models and annotation of their function. The complete HEB-25 population will be assessed to construct the first wild barley pan-genome. This will allow deep calling of variations in coding and regulatory regions to investigate SNPs, presence/absence and structural variations between HEB-25 lines and available domesticated barley cultivars. With this comprehensive approach HAPPAN is expected to reveal novel alleles of diversity, but also find novel genes that are most likely derived from duplication and sub-functionalisation events. HAPPAN will define haplotypes and provide an ultra-high resolution of DNA markers. With the definition of haplotype groups for the diverse wild barley panel we will enter a new era of haplotype based analysis for barley breeding and research.Since 2014, the set of 1,420 NAM lines of the HEB-25 population are continuously analysed in regional and global field trials for variation in important agronomical traits like plant development, yield formation, pathogen resistance and stress tolerance. Based on the HAPPAN pan genome data this large phenotypic data collection will be exploited to map and, ultimately clone the causative genes controlling the studied traits. We believe that the accuracy and precision of this novel resource will allow to substantially accelerate the pace of breeding improved barley cultivars better adapted to changing environments.