Abstract:

The rooting characteristics of the twig cuttings of Pinus massoniana was observed to investigate the dynamic changes of relevant endogenous components during rooting process, including the activity of related oxidative enzymes (PPO,POD,IAAO) and the content of flavonoid and nutritive substances and so on. Results showed that rooting of Pinus massoniana was derived from the callus. When its cutting was treated by root stimulate GGR6 in a suitable concentration, rooting rate and the quality of root system could be significantly enhanced. Moreover, dynamic state of the endogenous components in Pinus massoniana plantlets can also be changed. Changes of the most endogenous components displayed regular pattern during the cutting. The activity of PPO and IAAO increased during induction period of the callus, reached to a peak during the formation period of callus, and started to decrease during the formation of root system. Whereas the activity of POD reached to a peak in the formation of both root systems and callus. The content of endogenous flavonoid decreased gradually at early stage of cutting, increased sharply 30-50 days later and reached to a peak when callus formed considerably, and then it started to decrease gradually. The content changes of flavonoid had relationship with the activity of peroxidase (POD); peak value of the activity of POD was always accompanied by a sharp decrease of the content of flavonoid. The content of soluble sugar increased gradually after cutting, reaching to a peak when most cuttings rooted, and then it decreased gradually. The content of total nitrogen changed irregularly during the whole process and the amplitude of variation was very small.

Key words: Pinus massoniana, rooting characteristics, oxidases, flavonoids, nutrients