The Study On Changes Of Physiological Indexes In Dormant Floral Buds Of Apricot And Methods To Break Dormancy

Deciduous fruit trees protected cultivation is a new and efficiency culture form in northern China. The experiment was carried out with Golden sun and Katy as experiment materials, investigating and calculating the chilling requirements of apricot floral buds, comparing the applicability of ≤7.2℃ model and 0~7.2℃ model and Utah model, analyzing the physiological changes in dormant floral buds protected cultivation, studying the effect of different materials of breaking dormancyon breadking apricot buds dormaney and on floral organs.1.The apricot floral buds had different chilling requirements significantly between different cultivars.By hydroponics we knew dormancy of golden sun protected cultivation was broke on Dec. 16 and the date in field is also oh Dec.22. Dormancy of Katy protected cultivation was broke on Dec.7 and the date in field is also on Dec. 16. Calculating the chilling requirements with ≤7.2℃ model, Golden sun is 1332h and Katy is 1262h. The experiment indicated that ≤7.2℃ model is more applicable than 0-7.2 ℃ model and the Utah model in location.2. The carbohydrate content has jump-changes.in dormancy-broken period. Starch and soluble sugar had the contradict changes trends during the breaking-rest period. The date soluble sugar content rose and starch content fell down sharply was consistent with the breaking dormant floral buds.3. With dormancy processin, SOD activity increased gradually and the activity fell down sharply near the period of breaking-rest. The decreasing trend of SOD activity was consistent with the period of breaking dormancy .POD activity was always lower in the former period of dormancy. IOD activity rose gradually with dormancy processin, however, the activity decrease swiftly and became a lower number when dormancy was broken .4. With chilling requirement increasing, O2- content rose constantly. H2O2 content was lower in the former period of dormancy, and H2O2 content rose constantly in the later period. But the contents of the two all fell down sharply during the period of breaking dormancy.5.GA4+7 treatment and 6-BA treatment and GA4+7+6-BA treatment all accelerated floral dormancy broken dramatically. And 6-BA treatment and GA4+7+6-BA treatment made the breaking rest earlier with 12 days also. GA4+7 treatment andGA4+7+6-BA treatment all improved floral buds longitude and horizon and angle. But the effect of 6-BA treatment was not obvious to floral development. 6. The mixture of thiourea and KNO3 broke dormancy earlier with also 6 days, and the effect of mixture was superior to simple thiourea treatment, and there was not obvious effect with KNO3 treatment. Medical treatment all improved activities of SOD and POD dramatically, and decreased H2O2 content. From the treatment period of using chemical substance, the middle period of dormancy was superior to the early period .The medicals all decreased pollen vitality and pollen germination rates, and inhibited the expansion of floral buds and the increasing of angle, and decreased the rata of longitude and horizon of floral buds and the diameter of flowers.