The European hazelnut (Corylus avellana L.) is a tree crop of economic importance worldwide, but especially for northern Turkey, where the majority of production takes place. Hazelnut production is currently challenged by environmental stresses, such as a recent outbreak of severe powdery mildew disease; furthermore, allergy to hazelnuts is an increasing health concern in some regions. In order to provide a foundation for using the available hazelnut genetic resources for crop improvement, we produced a fully assembled genome sequence and annotation for a hazelnut species, from C. avellana cv. ‘Tombul’, one of the most important Turkish varieties. A hybrid sequencing strategy, combining short reads, long reads and proximity ligation methods, enabled us to resolve heterozygous regions and produce a high‐quality 370‐Mb assembly that agrees closely with cytogenetic studies and genetic maps of the 11 C. avellana chromosomes, and covers 97.8% of the estimated genome size. The genome includes 27 270 high‐confidence protein‐coding genes, over 20 000 of which were functionally annotated based on homology with known plant proteins. We focused particularly on gene families encoding hazelnut allergens, and the Mildew resistance Locus O (MLO) proteins that are an important susceptibility factor for powdery mildew. The complete assembly enabled us to differentiate between members of these families and to identify homologues that may be important in mildew disease and hazelnut allergy. These findings provide examples of how the genome can be used to guide research and to develop effective strategies for crop improvement in C. avellana.

中文翻译：

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欧洲榛（Corylus avellana L.）的染色体规模的基因组组装揭示了作物改良的目标

欧洲榛子（Corylus avellana  L.）是一种在世界范围内具有重要经济意义的林木作物，但特别是对于土耳其北部，那里的大部分产品都来自该地区。榛子生产目前受到环境压力的挑战，例如最近爆发的严重白粉病；此外，在某些地区，对榛子的过敏也越来越引起人们的健康关注。为了为利用可利用的榛子遗传资源改善作物提供基础，我们制作了一个完整的基因组序列，并为榛子种提供了榛子种的注释。简历。'Tombul'，最重要的土耳其品种之一。结合短读，长读和邻近连接方法的杂交测序策略，使我们能够解析杂合区并产生高质量的370 Mb装配体，该装配体与11 C. avellana的细胞遗传学研究和遗传图谱非常吻合染色体，覆盖了估计基因组大小的97.8％。基因组包括27 270个高可信度蛋白质编码基因，其中超过20000个基因是基于与已知植物蛋白质的同源性进行功能注释的。我们特别关注编码榛子过敏原的基因家族，以及对白粉病重要的易感性因子的霉菌抗性基因座O（MLO）蛋白。完整的大会使我们能够区分这些家族的成员，并鉴定出可能对霉菌病和榛子过敏症很重要的同系物。这些发现提供了基因组如何用来指导研究和开发有效的改良乌。子作物的策略的例子。