Phytochemical content of the wild and cultivated Brassica (n=9) collection of the ECPGR “COCHEVA BRAS” project

The COCHEVA BRAS Brassica collection was grown in Catania and it was represented by 26 landraces representing different crops of B. oleracea (10 of Portuguese provenance and 16 of Italian one) 7 F-1 hybrids of B. oleracea and 6 wild Italian Brassica species. Plants were transplanted in July and at the beginning of the flowering stage leaf samples were randomly collected from three single plants per accession. Samples were rapidly frozen and lyophilized, and then stored at -20 degrees C until further analysis. The phytochemical content of the Brassica collection was evaluated through the measurement of glucosinolates (GLS), ascorbic acid (AsA) and polyphenols (PP). Additionally, the antioxidant capacity was measured as DPPH center dot quenching potential. The GLS composition showed a strong diversity within the assayed genotypes. The amount of total GLS varied from 3 to more than 50 mu g g(-1) dw. Different GLS profiles were detected, particularly among the Italian landraces, which were characterized by a larger diversity of crops in the collection. The Portuguese landraces were characterized by the greatest presence of sinigrin, while the F1 hybrids were mainly constituted by neoglucobrassicin and wild Brassica species by glucoraphanin. The mean AsA level was significantly higher in Portuguese compared to Italian accessions (262.1 and 186.1 mg 100 g(-1) dw, respectively), but the highest value (708.1 mg 100 g(-1) dw) was observed in an Italian landrace, the same with the highest GLS content and DPPH quenching capacity. The level of PP strongly varied among the analyzed accessions. In fact, the PP content ranged from 784.6 to 2878.0 mg 100 g(-1) dw in Portuguese accessions, and from 655.9 to 2845.0 mg 100 g(-1) dw in Italian ones. The PP profiles were similar and characterized by 40-42% of sinapoyl derivatives, 30-32% of kaempferol derivatives and 25-28% of caffeic acid esters. The average coefficient of plant-to-plant variation was about 30%. The results of the present evaluation allowed identifying a group of accession as the most appropriate for the European Collection of the European Genebank Integrated System (AEGIS).