Apigenin, an anticancer secondary metabolite, is produced in fruits, vegetables, and herbs, and has been used to prevent patient resistance to cancer treatments. Petroselinum crispum (parsley) is one of the highest natural producers of apigenin. Three parsley cultivars, ‘Darki’, ‘Giant of Italy’, and ‘Wega’, were trialed in an indoor vertical hydroponic system to determine biomass production and apigenin accumulation. The cultivar ‘Giant of Italy’ was selected as the superior cultivar with 0.16 mg apigenin accumulated in each plant and significantly higher biomass than the other cultivars. A viable strategy for increasing secondary metabolite production in plants is through polyploid induction. Although polyploid induction has not previously been used to increase apigenin, it has been used to increase production of other secondary metabolites including quercetin and kaempferol. ‘Giant of Italy’, which has been reported as 2n = 2x = 22, was induced to form tetraploid tissue by treating seeds with an antimitotic agent. Seed germination decreased with increasing treatment concentration and the surviving seeds were grown to maturity in a greenhouse. New leaf tissue was harvested for analysis, and tetraploid cells were confirmed using flow cytometry. Polyploid induction of ‘Giant of Italy’ in this study suggests potential for elevated apigenin production.
