| The experiment had been carried out in Taian Qunxing orchard from 2004 to 2005 with 7-year-old nectarine'shuguang'(Prunus persica var. nectarina Maxim. cv. Shuguang) trees. The changes of Salicylic acid and Hydrogen peroxide in nectarine buds during endodormancy and the effect of plant growth regulators treatment on SA and H2O2 contents and the effect of SA and H2O2 treatments on the release of endodormancy of nectarine buds were analyzed and studied. The main results were as follows:1,The content of Salicylic acid decreased steadily in the primary stage of endodormancy and increased quickly in the later stage of endodormancy. In the middle stage of endodormancy Salicylic acid retain low level, with the release of endodormancy the content of SA raised. Content of SA in flower buds changed 7 days earlier than vegetative buds. The content of Hydrogen peroxide in nectarine buds increased in the primary stage of endodormancy and decreased steadily in the later stage of endodormancy. The content of H2O2 retain high level in the hole deep dormancy, and the content of H2O2 in flower buds than that of vegetative buds.2,The effects of different plant growth regulators treatment on the content of SA and H2O2 at different period of endodormancy: 6-BA,GA3 increased the content of SA but decreased the content of H2O2 of the hole endodormancy, The effect of ABA treatment was contrary to that of 6-BA,GA3 treatment. 6-BA,GA3 treatment postponed the accumulation of SA in the primary stage of endodormancy while promoted it in the later stage. ABA treatment promoted the accumulation of H2O2 in the primary stage of endodormancy but postponed it in the later stage; The effect of 6-BA,GA3 treatment was contrary to that of ABA treatment.3,Different concentration of SA had effects in the release of dormancy in different period of endodormancy. 0.1 and 1.0 mol·L-1 SA especially 1.0 mol·L-1SA can break the dormancy in the middle stage obviously; While the effect of 10 mol·L-1 SA can restrain the germination of vegetative buds. SA treatment promote the accumulation of H2O2 in the primary stage of endodormancy and accelerate the decompounds of H2O2. Low concentration of SA accelerates the changing course of phenolics and break the dormancy, high concentration of SA had the contrary effect.4,Different concentration of H2O2 had different function in endodormancy. 0.5% and 1% H2O2 treatment can break the dormancy evidently in the middle stage, but 1% H2O2 can damage the bud livability. While 2% H2O2 treatment restrain the break of dormancy of the hole stage. H2O2 treatment accelerates the accumulation of phenolics in the primary stage of endodormancy and promotes the decompounds of phenolics in the later stage.5,ABA treatment raised the SOD activity and made POD activity decreased, the effect of 6-BA,GA3 treatment was contrary to that. 6-BA and GA3 treatment decreased the SOD activity obviously in the primary stage of endodormancy. External SA treatment raised the SOD and POD activity of all the dormancy, the effect of 10mmol·L-1SA treatment was better than 0.1 and 1mmol·L-1. H2O2 treatment also raised the activity of SOD and POD in the dormancy, 2% H2O2 treatment was the best of three different concentration.6,ABA treatment keep the PAL activity remain high level in the hole endodormancy, but decreased the PPO activity; 6-BA and GA3 treatment little drop PAL activity and raised the activity of PPO. Of the hole period of dormancy SA treatment raised the PAL and PPO activity; In the primary stage of dormancy SA treatment accelerate the raise of PAL activity, but restrain its dropping in the later stage. H2O2 treatment also raised the activity of PPO and PAL, but it restrain the dropping of PAL activity in the later stage. |
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