Physiology Responses Of Kiwifruit Seedlings To Re-Watering And Exogenous Application Of Abscisicacidunder Drought Conditions

Fruits are subjected to drought stress that adversely affects growth, metabolism, and yield in the Northwest of China. Kiwifruit as a droughtsusceptible fruit that sustain drought stress injures during planting process. We take Actinidia deliciosa qinmei (one-year-old seedlings) and Hayward (two-year-old seedlings) as materials, research the effects of kiwifruit seedlings, such as chlorophyll, MDA, H2O2 content, membrane permeability, antioxidant enzyme activities and antioxidants contents, and studied the guidance of drought resistance of kiwifruit to re-watering and abscisic acid (ABA), meanwhile, discuss the physiological responses of kiwifruit to drought stress and different inductions for improving drought resistance, it provides theoretical basis for planting and breeding variety of kiwifruit.The results were as follows:1. The relative membrane permeability, MDA and H2O2 concentrations in kiwifruit leaves increased under drought stress, and the activities of SOD, CAT, POD, APX, GR all increased earlier and followed by a decline; proline accumulated continually, the contents of AsA and GSH increased earlier and followed by a decline.2. For improving growth condition and remitting injuried of kiwifruit, different time of re-watering producing different effects and the effect of re-watering after 6 d is better than re-watering after 9 d. Such as photosynthesis, intercelluar CO2 concentration, peroxidase and nitrate reductase activities, and the contents of chlorophyll and soluble proteins, the effect of re-watering after 6 d is even better than control, reached to significant difference, however, the treatment of re-watering after 9 d did not improve distinctly drought resistance for kiwifruit.3. Leaves were treated with 60μM exogenous ABA, the content of MDA and H2O2 decreased, improved membrane permeability, the activities of SOD, CAT, POD, APX, GR and the contents AsA,GSH,endogenous hormones and partly organic acids all increased, thereby enhancing drought resistance for kiwifruit seedlings, meanwhile, for the different using methods, the effect of sustaining ABA is better than control and disposable ABA, the effect of using ABA after 4 d is better than control and using ABA after 6 d.