LIGNIFICATION OF BAMBOO (PHYLLOSTACHYS-HETEROCYCLA MITF) DURING ITS GROWTH

Transverse and longitudinal progresses of lignification in the culm of Phyllostachys heterocycla was investigated from the stage of the sprout to the full grown culm within one growing season, combined with the observation of external morphology of the culm. Lignification was also investigated by chemical analysis in the 2, 3, 6, 8, 10, 12, and 14 years-old culms-The results obtained are as follows: (1) Lignification within one internode proceeds downward from upper to lower side, (2) transverse progress of lignification proceeds inward from outside to inside of the culm, (3) axial progress of lignification in the component cells of epidermal cells, fibers and parenchyma cells proceeds upward from the basal internode to the top one, (4) lignification of epidermal cells and fibers precedes that of ground tissue parenchyma and sclerotic parenchyma cells, (5) lignification of fibers initiates at the basal internode early in the elongation of the culm and occur in all internodes at the full elongation of culm; however, the lignification of parenchyma cells does not occur in the upper internodes at the full elongation of the culm, (6) the massive lignification of the parenchyma cells occur after the growth of new lateral shoots and leaf flush, and reaches to its highest level after the full opening of new leaves, (7) full lignification of the component cells completes within one growing season. Any further progress of lignification in any kind of component cells is not suggested to occur in the aged culm. © 1990, Walter de Gruyter. All rights reserved.