Research Institute of Forestry, Chinese Academy of Forestry/Key Laboratory of Tree Breeding and Cultivation of the State Forestry and Grassland Administration, No.1 Dongxiaofu, Xiangshan Road, Haidian District, Beijing 100091, China.
National Hazelnut Industry Innovation Alliance/Hazelnut Engineering and Technical Research Center of the State Forestry and Grassland Administration, Xiangshan Road, Haidian District, Beijing 100091, China.
Gigascience. 2021 Apr 19;10(4). doi: 10.1093/gigascience/giab027.
Corylus heterophylla Fisch. is a species of the Betulaceae family native to China. As an economically and ecologically important nut tree, C. heterophylla can survive in extremely low temperatures (-30 to -40 °C). To deepen our knowledge of the Betulaceae species and facilitate the use of C. heterophylla for breeding and its genetic improvement, we have sequenced the whole genome of C. heterophylla.
Based on >64.99 Gb (∼175.30×) of Nanopore long reads, we assembled a 370.75-Mb C. heterophylla genome with contig N50 and scaffold N50 sizes of 2.07 and 31.33 Mb, respectively, accounting for 99.23% of the estimated genome size (373.61 Mb). Furthermore, 361.90 Mb contigs were anchored to 11 chromosomes using Hi-C link data, representing 97.61% of the assembled genome sequences. Transcriptomes representing 4 different tissues were sequenced to assist protein-coding gene prediction. A total of 27,591 protein-coding genes were identified, of which 92.02% (25,389) were functionally annotated. The phylogenetic analysis showed that C. heterophylla is close to Ostrya japonica, and they diverged from their common ancestor ∼52.79 million years ago.
We generated a high-quality chromosome-level genome of C. heterophylla. This genome resource will promote research on the molecular mechanisms of how the hazelnut responds to environmental stresses and serves as an important resource for genome-assisted improvement in cold and drought resistance of the Corylus genus.
榛（Corylus heterophylla Fisch.）是桦木科榛属植物，原产于中国。作为一种具有重要经济和生态价值的坚果树种，榛能够在极端低温（-30 至-40°C）下生存。为了加深对桦木科物种的认识，促进榛的利用，进行杂交育种和遗传改良，我们对其进行了全基因组测序。
基于 >64.99 Gb（约 175.30×）的纳米孔长读序列，组装得到一个 370.75-Mb 的榛基因组，其 Contig N50 和 Scaffold N50 大小分别为 2.07 和 31.33 Mb，分别占估计基因组大小（373.61 Mb）的 99.23%。此外，使用 Hi-C 连锁数据将 361.90 Mb 的 Contigs 锚定到 11 条染色体上，代表组装基因组序列的 97.61%。还测序了代表 4 种不同组织的转录组，以辅助预测蛋白编码基因。共鉴定到 27591 个蛋白编码基因，其中 92.02%（25389 个）具有功能注释。系统发育分析表明，榛与麻栎（Ostrya japonica）亲缘关系较近，它们与共同祖先分化的时间约为 52.79 百万年前。
我们生成了一个高质量的榛染色体水平基因组。该基因组资源将促进对榛响应环境胁迫的分子机制的研究，也将为榛属植物的耐寒和耐旱性的基因组辅助改良提供重要资源。
