The Effects Of Different Cutting Root Ratios On Plant Hormones In P.Orientalis

The root directly contacting with the soil is a form of existence that the biological Ecosystem exists.The ecological function of the Ecosystem depends on the root system underground. So the well developed root system is vital to the high quality seedling in the restoration. As known from the practice that root cutting can stimulate a large amount of fibrous roots and the side roots when cultivating P.orientalis seedling. And the development of the root cutting underground is closely related to the survival rate of restoration. Therefore, the quality of the seedling can be assessed on the sturdy stem and the well developed root system. However, the contents of plant hormones in the P.orientalis seedlings after rooting cutting will have the same changes. Dividing Platycladus orientalis to four groups, root cutting 1/2, root cutting1/3, root cutting 1/4 and the whole root, research on the changes of the hormone contents in a short period and its response on the root cutting under different rations. The main results are presented as follows:The root cutting is the main cause of the enhancement in ABA in the root of Platycladus orientalis. Afer the treatments of different root cutting, Platycladus orientalis accumulate ABA in a high speed, and its content in root system increase rapidly to inhance the stress-resistance of the root. And the changes of ABA contents are comparatively obvious under treatmen of 1/2 root cutting which deeply hurt the root system, especially under 1/2 root cutting treatment..The levels of the CTK and GA in the root system decrease after root cutting treatment which promote the growth of the plants. However, the IAA contents increase slightly. The 1/2 root cutting treatment changes obviously in the early stage of the experiment, each content decreases quickly compared with the other treatment.The changes of IAA after root cutting in the root of Platycladus orientali complicated, without any decreasing, on the contrary it have a slightly increasing, it balances the restraining of the high ABA contents after root cutting in some way.Ordinarily, the modulation on the growth and the development of the plant that the plant hormones affect on is not a separate effect.In this experiment, each hormone is compared with as the hormone can occur between the synergistic or antagonistic effect. From the test, it shows that the changes of the hormons ratios are more complicated. The relationship of the hormones under various dynamics and balance in the plant also need study further.