Deciphering variation of 239 elite japonica rice genomes for whole genome sequences-enabled breeding.

Revealing genomic variation of representative and diverse germplasm is the cornerstone of deploying genomics information into genetic improvement programs of species of agricultural importance. Here we report the re-sequencing of 239 japonica rice elites representing the genetic diversity of japonica germplasm in China, Japan and Korea. A total of 4.8 million SNPs and PAV of 35,634 genes were identified. The elites from Japan and Korea are closely related and relatively less diverse than those from China. A japonica rice pan-genome was constructed, and 35 Mb non-redundant novel sequences were identified, from which 1131 novel genes were predicted. Strong selection signals of genomic regions were detected on most of the chromosomes. The heading date genes Hd1 and Hd3a have been artificially selected during the breeding process. The results from this study lay the foundation for future whole genome sequences-enabled breeding in rice and provide a paradigm for other species.