The bioactive profile of lettuce produced in a closed soilless system as configured by combinatorial effects of genotype and macrocation supply composition

Abstract

The effect of cultivar and nutrient solution macrocation proportions (S K , S Ca , S Mg ) on the bioactive content of hydroponically cultivated lettuce was evaluated on two lettuce cultivars (red and green-pigmented Salanova®) grown in a fully controlled Fitotron® chamber. Fresh weight and color attributes were superior in green Salanova and in S K -treated plants, while elevated macrocation proportions (S K , S Ca , and S Mg ) affected the corresponding minerals, P and Na content. S Ca and S Mg treatments raised ascorbate concentration and reduced nitrate levels in treated plants. Chicoric and chlorogenic acids were higher in red over green Salanova. Chlorogenic acid was higher in S Ca and S Mg plants and chicoric acid levels were S Mg > S Ca > S K . The S Mg -treated red Salanova contained higher concentrations of target carotenoids. In conclusion, nutrient solution management constitutes an effective cultural practice to increase bioactive properties and functional quality of hydroponically grown lettuce.