Chemical characterization of wild populations of Brassica oleracea complex species (n=9) for the content of their bioactive compounds

The wild species belonging to Brassica oleracea complex species (n=9) are widespread in the Mediterranean basin and represent the relative species of several vegetable crops, such as broccoli, cauliflower, kale, cabbage. They are characterized by the high level of bioactive compounds, such as glucosinolates (GLSs), known for their benefits for human health. Four accessions were evaluated: B. macrocarpa (BM) from Favignana (Trapani), B. trichocarpa (BTR) from Monte Gallo (Palermo), B. villosa (BV) from Monte Occhio (Palermo) and B. rupestris (BX) from Scalfani Bagni (Palermo). All these populations are widespread in the central-western Sicily inland areas and along the northwestern coast, in limestone cliffs or rarely sandstone, usually with exposure to the North or in shady positions, from sea level up to 1000 m. The accessions were stored in the genebank of Catania University. Characterization trial was performed in an open field in Catania (37°31’N, 15°4’E at 105 m a.s.l.) applying organic practices and with irrigation when required. Ten plants per populations were grown in open field in randomised blocks. The leaves were characterized by using the international descriptors IBPGR and UPOV, such as, area (m2), height (cm), longitude (cm) and colour as well as days to flower (g.d.). Leaves were freeze-dried and analysed to determine bioactive metabolites such as: phenolic compounds, glucosinolates. B. trichocarpa had the highest value of polyphenols 1.63 mg g-1 dw while B. macrocarpa showed the lowest one (0.01 mg g-1 dw). B. villosa showed highest level of glucoraphanin (35.2 Ɋmol g-1 dw). The results obtained showed high variability within the same population that present different morphometric traits and biochemical profile.