A broad definition of quality in grains is how well-suited they are to their intended use. This can include traits such as moisture content, kernel hardness, color, and susceptibility to fungal infections. Since maize is frequently used for food or feed, its nutritional value is an important quality trait. One of the main limitations to maize nutritional quality is its low content of the amino adds lysine, tryptophan, and methionine. If one amino add is deficient in a diet, other amino acids cannot be used efficiently (Fig.l).Thus, more protein can be made available in maize-based diets by changing the relative levels of certain amino adds without altering the protein content of the seed. To date, mutation breeding has been the most successful method to improve the amino acid balance of maize (Vasal 2001 ). Here we present resu1ts of our efforts to alter amino add balance using plant breeding and genetic engineering approaches.

English

0309|AGRIS 0301|AL-Maize Program

Juan Carlos Mendieta

CIMMYT Publications Collection