BARLEY-NAM: Locating exotic genes that control agronomic traits under stress in a wild barley nested association mapping (NAM) population

面对气候变化，要实现可持续的粮食生产，需要在不断变化的不利环境条件下培育出高产和可持续产量的作物。现代作物的原始野生种质含有能够实现这一目标的等位基因变异，但现代作物的生物多样性正日益枯竭。成功利用野生种质的两个关键障碍是找到所需的野生衍生等位基因并在田间进行测试。大麦-NAM项目将使用野生大麦(Hordeum Uggare SSP)。Senstaneum)作为模式，并应用新的基因组和育种工具来改善在非生物和生物胁迫下的优良大麦的农艺表现。为此，我们将使用第一个谷物NAM群体Heb-25应用嵌套关联图谱(NAM)方法。Heb-25由1,420个BC1S3系组成，细分为25个家族，起源于精英大麦品种Barke与25个不同的野生大麦供体杂交。HEB-25品系将首先利用最先进的外显子组捕获和下一代测序，对21,643个基因(每个已知的高置信度大麦基因)的等位基因含量进行评估。我们预计将在HEB-25中定位大约40万个SNPs，从而使大麦的基因和基因组分辨率达到前所未有的水平。其次，所有Heb品系将在德国、苏格兰和以色列进行田间试验，以评估其在缺氮、干旱和病原菌侵袭下的农艺表现。将对产量构成因素和营养含量以及对大麦主要病害叶锈病、黄锈病和网斑病的抗性进行评分。此外，农艺性能将通过非侵入性遥感技术进行建模，以建立表型预测。第三，收集的数据集将被存档，并在中央数据仓库中进一步处理，该数据仓库围绕一个定制的可通过网络访问的关系数据库建立。第四，Heb-25的基因型和表型数据将在全基因组关联扫描(Gwas)中结合起来，以识别在胁迫下改善植物表现的野生大麦等位基因。由于基因分辨率极高，这项研究将产生个体高置信度候选基因，推测这些基因可以调节所研究的性状。第五，为了验证已鉴定的性状改良的外源等位基因，将从Heb系中分离出高分辨率的后代。大麦-不结盟运动项目将在两个方向上受益。一方面，调控大麦农艺性状的基因和基因变体将被定义在作物前所未有的详细水平上，这将为未来小麦和黑麦的平行改良战略提供信息。另一方面，性状改良的野生大麦等位基因也将在未来的大麦育种中得到应用。这将导致新的大麦品种具有更好的表现，并扩大精英大麦基因库的生物多样性和可持续性。

Delivering sustainable food production in the face of climate change requires a revolution in breeding crops that deliver high and sustainable yield under fluctuating disadvantageous environmental conditions. The ancestral wild germplasm of modern crops contains allelic variants that can achieve this goal, yet modern crops are becoming increasingly depleted in biodiversity. The two key obstacles to successful exploitation of wild germplasm are finding the wild-derived alleles needed and testing them in the field.The BARLEY-NAM project will use wild barley (Hordeum vulgare ssp. spontaneum) as a model and apply novel genomic and breeding tools to improve agronomic performance of elite barley under abiotic and biotic stresses. For this, we will apply the nested association mapping (NAM) approach using the first cereal NAM population, HEB-25. HEB-25 comprises 1,420 BC1S3 lines, sub-divided into 25 families, originating from crosses of the elite barley cultivar Barke with 25 different wild barley donors. The HEB-25 lines will first be assessed for allele content at 21,643 genes (every known high-confidence barley gene), employing state-of-the-art exome capture and next generation sequencing. We expect to map roughly 400,000 SNPs within HEB-25 giving unprecedented levels of gene and genome resolution for barley. Second, all HEB lines will be cultivated in field trials in Germany, Scotland and Israel to assess agronomic performance under nitrogen deficiency, drought and pathogen attack. Yield components and nutrient content will be scored, as well as resistance against the major barley diseases leaf rust, yellow rust and net blotch. In addition, agronomic performance will be modelled by non-invasive remote sensing technology to establish phenotype predictions. Third, the collected data sets will be archived and further processed in a central data warehouse, built around a custom web-accessible relational database. Fourth, genotype and phenotype data of HEB-25 will be combined in a genome-wide association scan (GWAS) to identify wild barley alleles that improve plant performance under stress. Since the gene resolution is extremely high, this study will yield individual high confidence candidate genes that putatively regulate the studied traits. Fifth, to validate the identified trait-improving exotic alleles, segregating high-resolution progeny will be developed from the HEB lines. The BARLEY-NAM project will be beneficial in two directions. On the one hand, the genes and gene variants regulating agronomic traits in barley will be defined at a level of detail unprecedented for the crop and this will inform future strategies for parallel improvement in wheat and rye. On the other hand, trait-improving wild barley alleles will be available for application in future barley breeding. This will lead to new barley cultivars with improved performance and extend the biodiversity and sustainability of the elite barley gene pool.