A Platform for Metabolomic QTL Mapping In Broccoli (Brassica oleracea)

Broccoli (Brassica oleracea var italica) is an ideal model for developing platforms to study metabolomic variation and their effects on health. Broccoli contains numerous compounds that have realized and putative impacts on health including sulfur containing compounds, fat soluble vitamins, phenolics, fatty acids, plant sterols and others. In addition, broccoli is a distant relative to the model plant species Arabidopsis which provides considerable information on the genetics and regulation of the respective biochemical pathways. A population of 160 recombinant inbreds from the VI-158 x BNC mapping population was used to identify QTLs associated with variation in secondary metabolites in broccoli. The population differs in aliphatic glucosinolates (glucoraphanin, progoitrin, glucoiberin, and sinigrin); carotenoids (b-carotene and lutein);  tocopherols (alpha and gamma) and other compounds of interest. Single nucleotide markers representing known gene sequences from B. oleracea, B. napus, and B. rapa have been designed and integrated into a genetic framework of SSR and AFLP markers to produce a saturated genetic linkage map. The population will also be used to conduct a non-targeted profiling of broccoli utilizing LC-MS with extraction procedures for both polar and non- compounds. Correlations between the occurrence of targeted and non-targeted profile peaks and bioactivity in cell assays will be discussed in regards to validating known compounds, identifying new compounds and studying the interaction between multiple compounds.