Abstract:

The physiological mechanism of bamboo aging was investigated by measuring endogenious phyto hormones, nutrients and C/N of the multched Phyllostachys violascens stands with different age. This study intended to develop a bamboo aging theory and find measures for improvment and rejuvinization of degraded bamboo stands. The results showed: 1) Bamboo aging promoted by multching was initiated in the rhizome, not involved in leaves. 2) Bamboo aging was regulated and controlled by the hormonal ratio of GA3/ABA, IAA/ABA, (GA3＋IAA)/ABA, i.e. bamboo aging was trigged when (GA3＋IAA)/ABA ratio declined below a threshold value, otherwise, the aging was prevented as its ratio was higher than a threshold value. In addition, GA3/ABA played a more important role than IAA/ABA in promoting senescence. Bamboo aging was involved in neither less synthesis of CTK in root, nor less upward transportation from root. CTK was not the hormone for inhibiting aging, and did not play role in aging inhibition. The results suggested the bamboo had a particular aging mechanism different with general plant, which may be attributed to its biological characteristics. 3) Bamboo aging was not caused by nutrient deficiency or rise of C/N, and rise of C/N was a result of hormonal regulation, but not a reason for the bamboo aging. The bamboo aging was regulated and controlled by hormones.

Key words: Phyllostachys violascens, aging, nutrient, hormone, C/N