Variation of Active Oxygen Metabolism,Anti-oxidation System in Grapevine Buds Tissue during Bud Dormancy Inducing and Releasing

This study aimed to investigate the bud dormancy mechanisms of wine grape during natural and breaking dormancy from the following physiological and biochemical aspects:water status,active oxygen and ant-oxidation system,phenols and the related enzymes.The results show that:(1)Chardonnay which is an early maturity variety comes into deep dormancy on Dec.20th,and bud dormancy starts to release gradually from Jan.29th;the late Cabernet Sauvignon's deep dormancy stage is from Jan.9th to Feb.18th and bud dormancy starts to release gradually.Cyanamid treatment enhanced dormancy release.(2)The contents of active oxygen species O-·2 and H2O2 had a gradual increase in the early dormancy stage,reaching the peak value at the deep end-dormancy,then decreased after bud dormancy release.SOD activity decreased steadily during the whole period of end-dormancy,and then increased after the dormancy release.POD and CAT activities kept increasing during the early dormancy stage,then the POD value started to drop after the dormancy release and CAT maintained a high activity until bud sprouting.ASA-GSH cycle was relatively weak at the early stage of end-dormancy,and then it was activated gradually during the dormancy release.During the breaking dormancy,the content of active oxygen,the activities of anti-oxidation system enzymes and the contents of antioxidants are changed,all of these are better for dormancy releasing.