Effects of Electrical Conductivity and Pruning on Secondary Metabolite Contents in Fruits of Jaltomata procumbens (Cav.) J. L. Gentry

Abstract

Jaltomata procumbens is a semidomesticated plant species used as food, and the presence of several types of secondary metabolites are detected in one of its forms. Growth conditions, the electrical conductivity (EC) of the nutrient solution, and the pruning management may influence the secondary metabolite content. The objective was to evaluate the effects of EC and pruning on the metabolite content of 2 J. procumbens forms, in greenhouse and hydroponics. Treatments included 2 forms (erect and decumbent), 3 EC levels (1, 2, and 3 dS m−1), and 2 pruning levels (with and without pruning). The contents of phenolic acids, flavonoids, and terpenoids were evaluated. EC and pruning management differentially influenced the contents of each group of metabolites in both forms in a combined and individual manner, with EC exerting a stronger effect than pruning. A total of 7 phenolic acids, 4 flavonoids, and 5 terpenoids were detected: the erect form contained significant amounts of syringic acid, rutin, and carnosol at 33.44, 36.43, and 0.26 mg 100 g−1 of dry weight, respectively, whereas the decumbent form had high contents of gallic and rosmarinic acids and morin at 59.03, 28.31, and 61.54 mg 100 g−1 of dry weight, respectively. Considering the variability observed depending on the metabolite group of interest, the specific management of EC and pruning is required for each form.