Variation in glucosinolate and mineral content in Galician germplasm of Brassica rapa L. cultivated under Mediterranean conditions

In the north of Spain and Portugal, turnip greens and turnip tops (Brassica rapa L. var. rapa), are highly appreciated for human consumption. To spread its cultivation to other regions of the Iberian Peninsula, a set of Galician germplasm of B. rapa (19 accessions) have been cultivated under Mediterranean edaphoclimatic conditions (Córdoba, Andalusia). Their agronomical performance and the glucosinolate content of harvested turnip greens and turnip tops have been analyzed. The total glucosinolate content ranged from 10.29 to 44.97 µmol g^-1 dw for turnip greens, and from 15.30 to 63.8 µmol g^-1 dw for turnip tops, gluconapin being the most abundant glucosinolate (near 80% of the total amount) in all samples analyzed. Seven selected accessions were also evaluated for mineral composition. The range of mineral concentrations in turnip greens and turnip tops, respectively, were: Ca (11.97-23.57; 4.63-32.25 mg g^-1), K (6.66-42.32; 5.73-13.37 mg g^-1), P (3.61-7.47; 3.32-10.07 mg g^-1) and Mg (1.44-2.29; 1.36-1.9 mg g^-1). Our results confirmed that Brassica rapa can be cultivated in Southern Spain to produce turnip greens and turnip tops having similar nutritive quality to those cropped in Galicia.