State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, No. 666 Wusu St., Lin'an District, Hangzhou 311300, China.
Novogene Bioinformatics Institute, No. 38 Xueqing Rd., Haidian District, Beijing 100083, China.
Gigascience. 2019 May 1;8(5). doi: 10.1093/gigascience/giz036.
Pecan (Carya illinoinensis) and Chinese hickory (C. cathayensis) are important commercially cultivated nut trees in the genus Carya (Juglandaceae), with high nutritional value and substantial health benefits.
We obtained >187.22 and 178.87 gigabases of sequence, and ∼288× and 248× genome coverage, to a pecan cultivar ("Pawnee") and a domesticated Chinese hickory landrace (ZAFU-1), respectively. The total assembly size is 651.31 megabases (Mb) for pecan and 706.43 Mb for Chinese hickory. Two genome duplication events before the divergence from walnut were found in these species. Gene family analysis highlighted key genes in biotic and abiotic tolerance, oil, polyphenols, essential amino acids, and B vitamins. Further analyses of reduced-coverage genome sequences of 16 Carya and 2 Juglans species provide additional phylogenetic perspective on crop wild relatives.
Cooperative characterization of these valuable resources provides a window to their evolutionary development and a valuable foundation for future crop improvement.
山核桃（Carya illinoinensis）和中国山核桃（C. cathayensis）是山核桃属（胡桃科）中重要的商业栽培坚果树种，具有很高的营养价值和显著的健康益处。
我们分别从一个山核桃品种（“ Pawnee”）和一个驯化的中国山核桃地方品种（ZAFU-1）获得了超过 187.22 和 178.87 吉字节的序列，以及大约 288×和 248×的基因组覆盖度。山核桃的总组装大小为 651.31 兆碱基（Mb），中国山核桃的总组装大小为 706.43 Mb。在这两个物种与胡桃属分化之前，发现了两次基因组加倍事件。基因家族分析突出了生物和非生物胁迫耐受性、油脂、多酚、必需氨基酸和 B 族维生素的关键基因。对 16 个山核桃和 2 个胡桃属物种的低覆盖率基因组序列的进一步分析为作物野生近缘种提供了更多的系统发育视角。
对这些有价值资源的合作研究为它们的进化发展提供了一个窗口，并为未来的作物改良奠定了宝贵的基础。
