Polysaccharides of tropical pasture herbage. I. Studies on the distribution of the major polysaccharide components of spear grass (Heteropogon contortus) during growth

Abstract

The total carbohydrate content of spear grass stalk and leaf at several different stages of growth has been separated into fractions by a sequence of extraction procedures and each major polysaccharide fraction has been analysed for its monomer composition. As growth advanced the low molecular weight carbohydrates (sucrose, glucose, fructose) decreased, while hemicelluloses and cellulose increased in relative amount. Hemicelluloses, which are the major type of component in the plant, were predominantly of the B-type in the leaf, but both A- and B-types were present in the stem. The hemicellulose A-fractions contained proportionately less arabinose and uronic acid and more xylose than the corresponding B-fractions.