Study On Changes Of Phenolics In Sweet Cherry Buds And It's Regulations On Endodormancy

The research had been carried out in Taian Qunxing orchard from 2003 to2005 with 7-year-old sweet cherries 'hongdeng'and 'zaohongbaoshi'(Prunusavium L.cv.Hongdeng and P. avium L.cv. Zaohongbaoshi) trees.It mainlystudied the changes of phenolics in sweet cherry buds duringendodormancy.The effects of temperature, plant growth regulators,chemicalmedicines and de-scaled treatments on the content of phenolics,relate enzymesactivity and release of endodormancy of sweet cherry buds were analyzed andstudied.The main results were as follows:1. The content of phenolics rose steadily in the primary stage ofendodormancy and decreased quickly in the later stage of endodormancy.Thetime which the content of phenolics decreased was different in differentcultivars.The content of phenolics decreased lowest when endodormancyreleased. The content of phenolics in flower buds was higher than that ofvegetative buds. PPO activity and PAL activity of flower buds were similar tothat of vegetative buds in the same cultivar, but differentiate notably indifferent cultivars. The trend of PAL activity was positively related with thetrend of the content of total phenolics. PPO activity rose steadily duringendodormancy. The trend of POD activity was similar to PPO activity.2. The effects of different temperature treatment on the content ofphenolics and release of endodormancy in different period of endodormancywere different: Low temperature (5℃) treatment promoted the accumulationof the phenolics in the primary stage of endodormancy,and made the phenolicscontent decreased earlier than that of control in the middle stage ofendodormancy,and promoted the decreases of the content of phenolics. Wihlethe effect of high temperature (20℃) treatment was contrary to that of lowtemperature (5℃) .There were no obvious effects on the content of phenolicsin flower buds after variable temperature (5℃/20℃) treatment. The effects ofdifferent temperature treatment on PAL ,PPO activity and the germination rateat different period of endodormancy were also different.3. The effects of different plant growth regulators treatment on thecontent of phenolics at different period of endodormancy were different: ABApromoted the accumulation of phenolics while 6-BA,GA3 postponed theaccumulation of phenolics in the primary stage of endodormancy.In the middlestage of endodormancy,ABA kept the content of phenolics high , 6-BA,GA3promoted the content of phenolics peek then it dropped;in the late period ofendodormancy, ABA postponed the drop of the phenolics content, while6-BA,GA3 were contrary to ABA.The effect of GA3 was better than that ofABA. The effects of different plant growth regulators treatment on PAL,PPOactivity and the rate of germination were different at different stage ofendodormancy:In the early stage of endodormancy, 6-BA,GA3 treatment madePAL activity decreased but raised the PPO activity,but the effects of6-BA,GA3 treatment on the rate of germination were not obvious. The effectsof ABA treatment was contrary to that of 6-BA,GA3 treatment ,and made therate of germination dorp. 6-BA,GA3 treatment made PAL activity decreasedbut raised the PPO activity in the middle of endodormancy,and made the rateof germination higher than 50% with the release of endodormancy. The effectsof ABA treatment was contrary to that of 6-BA,GA3 treatment .In the latestage of endodormancy the effects of three plant growth regulators weresimilar to the middle stage of endodorancy. 4. The effects of different chemical medicines treatments on the contentof phenolics at different period of endodormancy were different.KNO3 andsulfourea treatment slowed the content of phenolics accumulation speed,whileH2O2 treatment accelerated the content of phenolics accumilation, in theprimary stage of endodormancy. In the middle of endodormancy,the effects ofthis three chemical medicines treatments on the content of phenolics in'hongdeng'and 'zaohongbaoshi'sweet cherry flower buds were similar to theearly stage of endodormancy. KNO3 treatment reduced the content ofphenolics while sulfourea treatment made the content of phenolics increasedslightly, and H2O2 treatment remarkably increased the content of phenolics in...