Genomic insights into the origin, domestication and diversification of Brassica juncea

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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biological Evolution*
  • Chromosomes, Plant / genetics*
  • Domestication*
  • Genome, Plant / genetics
  • Hybridization, Genetic / genetics
  • Mustard Plant / genetics*
  • Plant Breeding*
  • Quantitative Trait, Heritable