Fatty Acid and Amino Acid Profiles of Selected Peanut Cultivars and Breeding Lines

Abstract

Experiments were performed on peanut (Arachis hypogaeaL.) to determine the relationship of fatty acid and amino acid profiles of 6 high oleic acid (HO) and 10 normal oleic acid genotypes (Experiment 1) and to establish the correlation between the concentration of oleic acid and that of the other fatty acids by investigation of 600 peanut genotypes (Experiment 2). In experiment 1, which comprised Florunner, SunOleic 95R, GA 2844, TX 896100, UF 91108, NC12C, and 11 breeding lines, oleic acid ranged from 79 to 82% for the HO genotypes, compared to 55 to 60% oleic acid for the normal oleic acid genotypes. The ratios of oleic to linoleic acids were 23:1 to 32:1 for HO lines and 2:1 to 3:1 for normal lines. Iodine values were 77 for HO lines compared to 82–93 for normal lines. HO lines also had 50 to 67% of the palmitic acid of the normal lines, and a higher ratio of unsaturated to saturated fatty acids. Glutamine/glutamic acid and asparagine/aspartic acid accounted for 36 to 40% of the total amino acids; amino acids present in lowest proportions were the sulfur-containing amino acids (cysteine and methionine) followed by threonine and lysine. The proportion of any given amino acid varied less than 1.5-fold among genotypes, with the exception of histidine (1.65-fold) and methionine (2.1-fold). There was no significant relationship between the proportion of individual or total essential amino acids or and the HO trait. In the second experiment oleic acid content was comprehensively evaluated in relation to other fatty acids. The highest correlations were noted for oleic and linoleic acids (r= −0.99) and for oleic and palmitic acids (r= −0.95). A positive relationship occurred between oleic acid and eicosenoic acid and weak inverse relationships occurred between oleic and behenic, arachidic, stearic, and lignoceric acids. Oleic acid content was inversely related to iodine value (r= −0.95) and positively correlated to the ratio of unsaturated to saturated fatty acids (r= 0.86).