Cereal Chem 68:482-486 | VIEW
Changes in Dry Matter and Protein Fractions During Kernel Development of Quality Protein Maize.
E. I. Ortega, E. Villegas, M. Bjarnason, and K. Short. Copyright 1991 by the American Association of Cereal Chemists, Inc.
Changes in dry matter, protein fractions, and quality during kernel development of quality protein maize (QPM) as a consequence of the interaction between the opaque-2 (o2) gene and modifier genes were investigated. Protein quality of QPM (i.e., total protein and zein content, tryptophan and lysine levels, and in vitro protein digestibility) was determined at different stages of kernel development for three normal and three QPM populations. Dry-matter accumulations of normal and QPM populations were very similar. QPM contained significantly higher amounts of tryptophan and lysine than did normal maize at early stages of kernel development. Protein-fraction distribution from 14 days after pollination through harvest showed large differences between types of maize, particularly in the prolamin components. Synthesis of zeinlike polypeptides during kernel development followed a characteristic pattern in the QPM endosperm. Isoelectric focusing of the zein and zeinlike fraction during kernel development revealed only minor differences, particularly in the zeinlike components.