Inheritance and gene mapping of the white flower in Brassica napus L.

Inheritance of the rapeseed (Brassica napus L.) white flower has not been extensively studied previously at the gene level, although it is a unique and useful marker trait. In this paper, rapeseed white flower inheritance was investigated by crossing/backcrossing a white flower inbred line with two different yellow flower inbred lines. We found that the white flower was monogenic and the white flower character was controlled by a pair of incomplete dominant genes. More importantly, by employing amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) technologies, we have identified three AFLP markers and two SSR markers that were closely linked to the white flower gene. The closest markers, EA06MG08 and EA11MG12, were mapped to be located at the either side of the white flower gene at a distance of 3.0 and 3.2 cM, respectively. In order to use the markers for white flower breeding, EA11MG12 was converted to a sequence-characterized amplified region (SCAR) marker. Furthermore, BLAST searches revealed that the sequences of the three AFLP markers showed good collinearity with their homologs on the Arabidopsis chromosome 5, indicating that the homolog of rapeseed white flower locus might exist between At5g49780 and At5g58230. Our results allow the formation of a gene map for the rapeseed white flower, providing further understanding about rapeseed white flower inheritance.