Cereal Chem 39:59 - 67.  |  VIEW ARTICLE

Nutritive Value of Central American Corns. VI. Varietal and Environmental Influence on the Nitrogen, Essential Amino Acid, and Fat Content of Ten Varieties.

R. Bressani, L. G. Elias, N. S. Scrimshaw, and M. A. Guzman. Copyright 1962 by the American Association of Cereal Chemists, Inc. 

Among ten corn varieties planted in Mexico, Guatemala, Nicaragua, and Panama in 1956, average values were: fat, 4.6%; nitrogen, 1.55%; leucine 618, isoleucine 231, valine 236, methionine 119, lysine 172, and tryptophan 26 mg. per g. of nitrogen. Significant locality differences were found in all nutrients assayed except valine. Over-all varietal differences were apparent only in isoleucine, but the presence of a significant locality x variety interaction for all nutrients studied, except fat, suggests that varietal differences may have been present in the different localities. Within-locality analyses confirmed this, indicating varietal differences in the four localities studied. Tryptophan and lysine, the two most limiting amino acids in corn, showed significant varietal differences at each of the four localities. The estimates of the variance components indicated that selection of varieties based on tryptophan, valine, and lysine content could be successfully undertaken at the local level simultaneously with selection for maximum yield. Correlations between total nitrogen and each of the amino acids studied were negative, but were significant only with isoleucine, valine, and tryptophan. Valine and tryptophan were positively correlated with isoleucine, lysine, leucine, and methionine, although the coefficients were statistically significant only with the first two.