Genetic linkage mapping of Arabidopsis lipid related genes in Brassica napus

To unravel the genetic basis of seed oil content in B. napus, here, we present a high-density molecular linkage map based on Brassica EST and BACs derived markers, which were sequence homology to corresponding Arabidopsis genes, especially for those involved in plant lipid biosynthesis or recycling pathways. A total of 374 newly developed markers were integrated into the framework of previously published SG map and formed a new map version of 477 markers with a combined map length of 1956.7 cM. Most of the newly added markers (74.9%; 280/374) are functional markers, and approximately half of them (137) exhibited high homology to 112 acyl lipid metabolism related genes in Arabidopsis. Comparative genomic analysis between B. napus and A. thaliana revealed 32 large syntenic regions. In parallel, a detailed QTL analysis for seed oil content was performed using the new map version across 11 environments and identified nine significant QTL. Co-location analysis revealed that a total of 28 acyl lipid metabolism related candidate gene loci were linked to seven of the nine QTL, indicating their potential role in genetic variability control on seed oil content.