Cereal Chem 53:327 - 337.  |  VIEW ARTICLE
Changes in Starch Granule Size and Amylose Percentage During Kernel Development in Several Zea mays L. Genotypes.

C. D. Boyer, J. C. Shannon, D. L. Garwood, and R. G. Creech. Copyright 1976 by the American Association of Cereal Chemists, Inc. 

Amylose concentration in starch reportedly increases with increasing physiological age of the tissue in which the starch is synthesized. Analyses of starches from developing maize (Zea mays L.) endosperms of two independently occurring amylose-extender (ae) alleles, named ae-Ref (Reference) and ae-il (induced-1), the double mutant amylose-extender sugary (ae su), and normal were consistent with this developmental pattern; however, the mutant waxy (wx) and the double mutant amylose-extender waxy (ae wx) were exceptions. The apparent amylose percentage of wx remained near zero and that of ae wx decreased during kernel development. Maximum starch granule size from all genotypes increased during kernel development from 18 to 36 days post-pollination, but granule size distributions varied among genotypes. Normal and wx kernels produced the largest granules. Compared to normal, the maximum granule size was reduced in ae- Ref, ae-il, and ae wx, resulting in an increased frequency of medium to small granules. Granules from ae su kernels generally were very small, although a few granules were as large as those from normal. When starch granules from 36-day-old ae-Ref, ae su, and normal kernels were separated into different size classes, a decline in apparent amylose percentage with decreasing granule size was observed. Thus, the smaller granules reflected the characteristics of unfractionated starch isolated from whole endosperms earlier in kernel development, supporting the hypothesis that these small granules were derived from physiologically younger cells.