The responses of enzymatic and nonenzymatic antioxidant systems of scion on different rootstocks under water stress deficit.

Selecting of the specific type of rootstock is an appropriate and shortterm method for increasing drought tolerance by improving the antioxidant systems in plants. In this research, the responses of the antioxidant systems of fig scion 'Sabz' were investigated on various rootstocks at different irrigation levels. Graft combinations were 'Sabz' on 'Sabz' (Sa/Sa), 'Siah' (Sa/Si) and 'Torch' (Sa/T) rootstocks, plus 'Sabz', 'Siah' and 'Torch' cultivars with no grafting, for a total of six groups. The plants were irrigated with 4 levels of 25, 50, 75 and 100% of water requirement (WR) for a duration of 12 weeks. The experiment was performed in a randomized complete design with 5 replications per treatment. The results showed that the 'Torch' rootstock induced the greatest amount of anthocyanin, glutathione and ascorbic acid in 'Sabz' (Sa/T) at 25% WR. Superoxide dismutase and catalase activities of 'Sabz' grafted on 'Siah' were more evidence compared to 'Sabz' grafted on 'Torch' rootstock at 25% of WR. The cv. Sabz grafted on both 'Siah' and 'Torch' rootstocks indicated higher chlorophyll content, chlorophyll stability index and shoot growth than cv. Sabz with no grafting. As a result, both rootstocks (T and Si) with the activation of enzymatic and non-enzymatic antioxidant systems caused the scion protects its integrity and be able to tolerate more water stress. [ABSTRACT FROM AUTHOR]