investigating the relationship between the accumulation of phenolic compounds in salustiana and italian orange cultivars with their rootstock fruits

the present study was done to investigate the correlation between biochemical changes of grafted tree fruits and rootstock fruits in gorgan university of agricultural science and natural resources in 2012-2013. for this purpose, the antioxidant activity and the total content of phenol and  flavonoid on four rootstocks such as yuzu (citrus junos), shelmahalleh (citrus sinensis var. shel mahalleh), citrumelo (citrus paradisi x poncirus trifoliate), sour orange (citrus aurantium) and italian and salustiana grafted tree were studied in skin and flesh of fruits. this research was done as a factorial experiment based on completely randomized design with three replications. the result showed that the measured parameters were significantly influenced by cultivar, rootstock and tissue. the highest amount of total phenol (21.38 mg/gdm) was recorded in italian skin on shelmahalleh rootstock. the most antioxidant activity (85.71 percent) was produced in the skin of citrumelo rootstock. the maximum content of total flavonoid (0.337 mg/gdm) was observed in the skin of salustiana on yuzu rootstock. the investigation indicated that the total phenol accumulation ability of rootstock fruit influences the antioxidant activity of the grafted tree fruits with a positive correlation although there was  significant differences between antioxidant compounds of grafted tree fruits with fruits of their rootstocks, but there was no relationship between them. it seems this was due to a combination of physiological characteristics of each group (grafted or not) of fruits.