Identification and Fine Mapping of the Candidate Gene Controlling Multi-Inflorescence in Brassica napus .

As a desirable agricultural trait, multi-inflorescence (MI) fulfills the requirement of mechanized harvesting and yield increase in rapeseed ( Brassica napus L.). However, the genetic mechanism underlying the multi-inflorescence trait remain poorly understood. We previously identified a difference of one pair of dominant genes between the two mapping parental materials. In this study, phenotype and expression analysis indicated that the imbalance of the CLAVATA ( CLV )- WUSCHEL ( WUS ) feedback loop may contribute to the abnormal development of the shoot apical meristem (SAM). BnaMI was fine-mapped to a 55 kb genomic region combining with genotype and phenotype of 5768 BCF 1 individuals using a traditional mapping approach. Through comparative and expression analyses, combined with the annotation in Arabidopsis , five genes in this interval were identified as candidate genes. The present findings may provide assistance in functional analysis of the mechanism associated with multi-inflorescence and yield increase in rapeseed.