The Redistribution of Stem Sugars in Wheat During Grain Development

In wheat, a study of the distribution of 14C assimilated by single leaves near the time of anthesis showed that, during ear development, sugars previously accumulated in the stem internodes were in part redistributed to other plant organs and in part probably converted to polysaccharides within the stem. Only a small proportion of the stem sugar (including fructosans) was lost in respiration. Upward movement of sugar" occurred almost entirely from the top two internodes only. The contribution to the final ear dry weight, however, was at the most only 5-10%. There was downward movement of sugars from the third and lower internodes and under the conditions of these experiments much of these went to newly formed tillers. There was little or no redistribution to the roots.