College of Agronomy, Hunan Agricultural University, Changsha, China.
Collaborative Innovation Center of Grain and Oil Crops in South China, Hunan Agricultural University, Changsha, China.
Nat Genet. 2021 Sep;53(9):1392-1402. doi: 10.1038/s41588-021-00922-y. Epub 2021 Sep 6.
Despite early domestication around 3000 BC, the evolutionary history of the ancient allotetraploid species Brassica juncea (L.) Czern & Coss remains uncertain. Here, we report a chromosome-scale de novo assembly of a yellow-seeded B. juncea genome by integrating long-read and short-read sequencing, optical mapping and Hi-C technologies. Nuclear and organelle phylogenies of 480 accessions worldwide supported that B. juncea is most likely a single origin in West Asia, 8,000-14,000 years ago, via natural interspecific hybridization. Subsequently, new crop types evolved through spontaneous gene mutations and introgressions along three independent routes of eastward expansion. Selective sweeps, genome-wide trait associations and tissue-specific RNA-sequencing analysis shed light on the domestication history of flowering time and seed weight, and on human selection for morphological diversification in this versatile species. Our data provide a comprehensive insight into the origin and domestication and a foundation for genomics-based breeding of B. juncea.
尽管早在公元前 3000 年就已开始驯化，但古老的异源四倍体物种芸薹属（Brassica juncea（L.）Czern & Coss）的进化历史仍不确定。在这里，我们通过整合长读长和短读测序、光学图谱和 Hi-C 技术，报告了一个黄籽芸薹基因组的染色体规模从头组装。来自全球 480 个样本的核和细胞器系统发育树支持芸薹属最有可能是在 8000-14000 年前在西亚单一起源，通过自然种间杂交形成。随后，通过三种独立的向东扩张途径，新的作物类型通过自发基因突变和基因渗入进化而来。选择清扫、全基因组性状关联和组织特异性 RNA 测序分析揭示了开花时间和种子重量的驯化历史，以及人类对这个多功能物种形态多样化的选择。我们的数据为芸薹属的起源和驯化提供了全面的见解，并为基于基因组学的芸薹属育种奠定了基础。
