Physiological And Biochemistrical Study On Flower Bud Differentiation In Picea Crassifolia

In this paper, the changes of endogenous hormones at the stage of flower bud differentiation in picea crassifolia was studied. In order to study more about the mechanism of flower bud differentiation; GA4+7 was applied alone or together with girdling by stem injection, effect on the change of endogenous hormones content was studied. It would be beneficial to the promotion of flower bud differentiation in picea crassifolia.It was observed that the time from May to the beginning of July was vegetative growth time, and then it would stop growing. From then to the middle of august was the physiological differentiation time. The results of study on changes of endogenesis hormone concentration show that GA, ABA and IAA both have two max value during the year growing time. ZR concentration was negatively correlated with flower initiation in many herbaceous species, also in Pinacea species. The results of study on the influence of stem injection with GA4/7 alone and in combination with girdling on changes of endogenesis hormone concentration show that both make the ZR concentration stay at a quite low level. While make the other 3 kinds of hormone's max value much more bigger than control.The ratio of different hormone was also studied, the results show that high ZR/GA, ZR/IAA, ZR/ABA value was positively correlated with floral bud initiation. High value of ABA/GA is necessary for floral bud differentiation.