a study of rootstock and low temperature effects on antioxidant reactions of page mandarin [(citrus reticulata ×c. paradise) × (c. clementina)]

the production of reactive oxygen species (ros) in plants under low temperature stress cause damage to plants. in order to evaluate of antioxidant responses of page mandarin young trees (two years old) on different rootstocks under low temperatures, an experiment was conducted in a factorial plan based on completely randomized design. treatment of temperatures were at seven levels include 9, 6, 3, 0.-3,-6 °c and 25 ± 2 °c (as control) and rootstocks were sour orange, citrange and trifoliate orange. results showed that, low temperatures increased electrolyte leakage, lipid proxidation, antioxidant capacity, superoxide dismutase, ascorbate peroxidase, catalase and peroxidase enzyme activities (p<0.01). due to effects of rootstocks lipid proxidation to 1.237 mda μmol/gr leaf fw (p<0.05) reduced, while increased antioxidant capacity and catalase enzyme activity respectively to 72.87% and 0.431 iu/gr leaf fw (p<0.01). results showed that interaction effect of factors were significant on, electrolyte leakage and apx activity (p<0.05). therefore maximum electrolyte leakage to 86.97% and ascorbate peroxidase activity to 4.620 iu/gr leaf fw were observed in page on sour orange in 6°c and trifoliate orange rootstocks in 0°c respectively. the biochemical indexes showed that page mandarin on trifoliate orange compared with sour orange and citrange rootstocks had best tolerance to freezing stress.