Genome-wide association study reveals a gene regulating plant height in .

Rapeseed () is an allotetraploid crop that is the main source of edible oils and feed proteins in the world. The ideal plant architecture breeding is a major objective of rapeseed breeding and determining the appropriate plant height is a key element of the ideal plant architecture. Therefore, this study aims to improve the understanding of the genetic controls underlying plant height. The plant heights of 230 rapeseed accessions collected worldwide were investigated in field experiments over two consecutive years in Wuhan, China. Whole-genome resequencing of these accessions yielded a total of 1,707,194 informative single nucleotide polymorphisms (SNPs) that were used for genome-wide association analysis (GWAS). GWAS and haplotype analysis showed that , which encodes BRASSINOSTEROID-INSENSITIVE 2 and belongs to the () family, was significantly associated with plant height in . Moreover, a total of 31 with complete domains were identified from genome and clustered into four groups according to phylogenetic analysis, gene structure, and motif distribution. The expression patterns showed that exhibited significant differences in 13 developmental tissues in , suggesting that may be involved in tissue-specific development. Sixteen genes were highly expressed the in shoot apical meristem, which may be related to plant height or architecture development. These results are important for providing new haplotypes of plant height in and for extending valuable genetic information for rapeseed genetic improvement of plant architecture.