Abstract: Effects of short-term heating at 40℃, 45℃ and 50℃ on bud livability, bud burst, the content of reactive oxygen and total phenolics, and the activity of related enzyme in‘Shuguang’nectarine bud were studied in order to investigate the mechanism of short-term heating releasing the endodormancy. The results indicated that effects of short2term heating on the endodormancy were differentwith date, temperature and continuous time of treatment. On November 30, compared with no2heating treatment ( control) , the date of
endodormancy release was postponed, the bud burst series and the rate of production in O₂· and ·OH, the content of H₂O₂ and the activity of CAT, POD, PPO enzyme were lower, and the content of total phenolics and the activity of PAL, SOD enzyme were higher on 40℃-heating treatment. Whereas, 45℃ and 50℃-heating treatment had the contrary effects. On December 10, 40℃-heating treatment nearly had the same results as control on the above factors, and the effects of 45℃ and 50℃-heating treatment on endodormancy release
were the same as the treatment on 30 November, and the effect of the former was superior to the latter. The decrease of the total phenolics content and the significant increase of reactive oxygen content and production rate were probably the cause of endodormancy release.

Key words: Nectarine, Bud, Heating, Endodormancy, Total phenolics, Reactive oxygen species