Heatmap of the expression levels. Heatmap of the expression levels of the studied candidate genes in seedling leaves of B. napus relative to the expression levels of the housekeeping gene Actin for the 509 inbreds of the diversity set. On the x-axis, the 15 candidate genes are plotted and the y-axis shows the 509 B. napus inbreds with their corresponding germplasm type. The dendrogram of the 509 B. napus inbreds is based on the gene expression data. Genes with a blue mark have an expression level lower than the expression levels of the housekeeping gene Actin and red marked genes have an higher expression level.