Crude protein content and aminoacid composition of seeds: variability and correlations

The main crop species (cereals, legume seeds and oilseeds) are reviewed with respect to their seed proteins. In the first section, a few points dealing with available analytical methods and nitrogen conversion factors are briefly discussed. The average crude protein contents of different cultivated species of grain are compared. The variability of seed protein content within a same species (phenotypic variations and biochemical mutations) is also discussed. The same kind of survey is then devoted to seed aminoacid composition in a second section. The analytical problems which are involved are summarized. The average aminoacid compositions of the main species are compared and the variations occurring within the same species are described, for the phenotypic ones as well as for some mutants. A last section concerns the relationships between aminoacid composition and protein content. The significance of these relations and their practical consequences are indicated.