TISSUE STRUCTURE, CELL MORPHOLOGY AND CELL WALL ULTRASTRUCTURE OF FIBER FOR DEBARKED GUANGYECHU

摘要

From analysis of tissue structure and cell morphology of debarked Guangyechu {Broussonetia papyri/era), the results indicated that the cells of fibers in xyleM had characteristics of tapering end and bulky bosoM with thin cell wall. Furthermore, big space in lumen and relatively small ratio of length to width had been also observed in our experimental work. Investigation of cell wall ultrastructure of fibers in xylem showed that there were some differences between Guangyechu and those common fiber materials applied for pulping and papermaking. Although cell wall was composed of P, S1, S2 and S3 layers, the primary wall with network-structured microfibrils and secondary wall S1 with axis-paralleled microfibrils were relatively thick. Specially, as far as the secondary wall S3 was concerned, microfibrils which were presented to be an organization of network were random and thin. They appeared transparent and closely clung to the cell-antrum. The angle of microfibrils to the fiber axis was narrower on S2 layer. Specific ultrastructure and higher content of polysaccharide could be the explanation for good beating properties and bonding strength obtained during pulping.