Abstract:

Abstract: our or five year old potted plants of Paeonia suffroticosa ‘Huhong’were subjected to the chilling treatment for different durations (1～7 weeks) to investigate the chilling requirements for shoot flush and flower initiation. Chilling was followed by forcing for up to 8 weeks in greenhouse until flowering finished. Based on the effects of different chilling durations on germination and flowering and the plant hormones dynamics during the chilling treatment, the process of the chilling treatment were divided into four stages of chilling accumulation, dormancy switching release, dormancy basically release and dormancy entirely release. The dynamic variation of GA₃, ABA, CTK, IAA and their ratio in the buds were tested in every chilling treatment stage and after moved into greenhouse. The results demonstrated that GA₃ and CTK induced, however ABA inhibited the dormancy release. The process of the release was well reflected in the change of the activators and inhibitor, among which the ratio of GA₃ to ABA was directly related to the dormancy releasing progress. Finally, it was proposed that chilling treatment result in dormancy release probably through regulating the balance of activators and inhibitors existed in the buds, and the progress of dormancy release of the buds was a result of multI-factors regulation.

Key words: Key words: Tree Peony, endogenous hormones, chilling temperature, dormancy release