Studies Of The Effects Of Extent Trunk On The Changes Of Endogenous Hormones At Different Position During The Growing Period In Panlownia

In order to study the Effects of extent trunk on the changes of endogenous hormones at different position during the growing period in panlownia,In this paper,useing 2a Paulownia tomentosa×P. fortunei 33 as experimental material,Using ELISA to measured the changes of Endogenous Hormones in the extent trunk branches (top branches), the upper branches, the central branches and the lower branches of the terminal bud,semi-mature leaves,mature leaves and roots, the results as follows:1) Compared with the natural state ,the change of IAA content in the whole growth period showed a more obvious pattern in the extent trunk state. IAA content of the extent trunk branches and the upper branches which are more vigorous parts is obvious trend higher from May to June, which is conducive to the rapid growth of trees. Different position of the tree showed this common characteristics in July, this common characteristic is most obvious in the upper branches and the trunk branches, this kind of promoter action becomes slower gradually in August and September, the lower position in the stem and roots were still maintaining the more obvious promoter action, thus lengthened its periods of growth.2)Similar with IAA, the GA3 content of the extent trunk state is higher than the natural state from May to July, but the changes did not like the IAA with apparent regularity, and the central trunk and upper branches are more obvious, namely, the obvious promoter action to the trees stem's department growth. During the same period, the GA3 content of the extent trunk is continued close to or slightly lower than the natural state. The high tendency of GA3 content in the leaves in May and June shift gradually to the terminal bud in July and August In the entire vegetal period.3) The content of ZR in the lower branches is higher in May and June,but, the content of ZR in the top branches is higher in July and August in the natural state. The content of ZR in the central branches and the lower branches in the extent trunk state is lower than the natural state,but,it is higher than the natural state from June to August. The ZR promoter action centralism to the leaves of the central branches and the lower branches in the extent trunk state. To September, the growth enters the last stage, this kind of promotion effect becomes slower obviously. Throughout the growing season, the content of ZR in the root is almost always in the lowest state.4) Throughout the growing season,the changes of the content of ABA at all different position in the extent trunk state is extremely similar to the natural state. The content of ABA elevates between 05-15 and 06-15, and it reached peak in 06-15,which show downward trend from 06-15 to 08-15 and stabilizes basically in the low level after 08-15. The content of ABA reached peak in 06-15 in the natural state. The ABA content of the root presents the peak on 06-15 in the natural state. The ABA content of the different position in the extent trunk is slightly higher than the natural state from July to September, the root high scope is most obvious.5) The ratio of (IAA+GA3+ZR)/ABA at all different position in the extent trunk state is slightly bigger than the natural state from May to June, especially the extent trunk branches and the upper branches are obvious,but the difference is not big in root between the extent trunk state and the natural state; the state shift to the central branches and the lower branches in July; The ratio at all different position in the extent trunk state is bigger than the natural state in August; the central branches and the lower branches and the roots extend this trend in September.