Variation in Amyloplast Size, Relative Numbers and Carbohydrate Composition During Endosperm Development in Sweet Corn

The fractionation of immature sweet corn endosperm amyloplasts into seven size classes throughout kernel development is described. The numbers in each size class, expressed as a percentage of the total, have been followed throughout development. In addition, the amylose content of the different size classes has been determined and in each case expressed as a percentage of their α-glucan content. The increase observed in percent amylose content of total amyloplast α-glucan during kernel maturation may be due both to changes in the relative numbers of the different size classes as well as to changes in their amylose content.