SEASONAL-VARIATION IN STORAGE CARBOHYDRATE AND CELL-WALL COMPONENTS OF THE CULM OF BAMBOO GRASS

Changes in the contents of storage carbohydrate (starch, sugar) and ce ll wall components were determined for the current and aged culms of b amboo grass (Sasa senanensis Rehd.) at about 2-week intervals during t he course of a single gear, except the period of dormancy (December-Ma rch). The contents of starch and free sugar in both the current and ag ed culms varied significantly; during the gear. They were low in summe r and high throughout the rest of tile year. The amplitude of the vari ations was somewhat greater in starch than in free sugar, although the variation pattern of these carbohydrates resembled each other. As fre e sugar, glucose oligomers were present in the culm extracts. The cont ents of cell wall polysaccharides and lignin in the current culms also varied significantly accompanying their growth, whereas those of the aged culms remained unchanged throughout the year. The lignin content of the current culms increased in correspondence with the culm growth, and full lignification was attained within one growing season. On the other hand, the deposition of cell wall polysaccharides, especially h emicellulose, completed in the early stage of the culm growth.