The ties of brotherhood between japonica and indica rice for regional adaptation

Sci China Life Sci. 2022 Jul;65(7):1369-1379. doi: 10.1007/s11427-021-2019-x. Epub 2021 Dec 9.

Abstract

Selection of beneficial genomic variants was crucial for regional adaptation of crops during domestication, but the underlying genomic basis remains largely unexplored. Here we report a genome-wide selective-sweep analysis of 655 japonica and 1,205 indica accessions selected from 2,673 landraces through principal component analysis to identify 5,636 non-synonymous single nucleotide polymorphisms (SNPs) fixed in at least one subspecies. We classified these SNPs into three groups, jiS (japonica- and indica-selected), jS (japonica-selected only), and iS (indica-selected only), and documented evidence for selection acting on these groups, their relation to yield-related traits, such as heading date, and their practical value in cropping area prediction. We also demonstrated the role of a jiS-SNP-containing gene in temperature adaptability. Our study informs genes underpinning adaptation that may shape Green Super Rice and proposes a time-saving, cost-reducing selection strategy of genomic breeding, sweep-SNP-guided selection, for developing regionally-adapted heterosis.

Keywords: geographic adaptation; indica-japonica differentiation; selective sweeps.

MeSH terms

  • Crops, Agricultural / genetics
  • Domestication
  • Hybrid Vigor / genetics
  • Oryza* / genetics
  • Plant Breeding