Effects of Different Rootstock on the Antioxidant Ability of ‘Tarocco’ Blood Orange Fruit

PurposeTo select suitable rootstocks that could improve the antioxidant capacity of ‘Tarocco’ blood orange.

MethodsPoncirus trifoliate L. Raf (Pt), Citrus reticulata Blanco (Cr) and C. junos Sieb. ex Tanaka (Cj) were used as the rootstock materials, and ‘Tarocco’ blood orange as scion. The effects of different rootstocks on the contents of total phenols, total flavonoids, soluble protein, soluble sugar, proline (Pro), and malondialdehyde (MDA), and the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) during fruit development were analyzed.

ResultsThe total phenols and total flavonoids content of blood orange grafted onto three rootstocks gradually decreased during fruit development, and the contents of total phenols and total flavonoids of fruits grafted onto Cr were higher than that on Cj and Pt. The soluble sugar and proline content of fruits grafted onto three rootstocks gradually increased, while the soluble protein and MDA content first decreased and then increased during fruit development. The activities of SOD, POD, APX of fruits grafted onto three rootstocks generally showed a trend from high to low, and the CAT activity first increased and then decreased during fruit development. The antioxidant enzyme activity of the three rootstocks was Cr>Cj>Pt. The correlation between each indexes of different rootstocks was strong.

ConclusionHigh contents of total phenols, flavonoids, soluble protein, soluble sugar and antioxidant enzyme activities are observed in fruits of ‘Tarocco’ blood orange grafted on Cr. Therefore, Cr can be used as an excellent rootstock for ‘Tarocco’ blood orange with strong antioxidant capacity.