Organic Acid Composition of Tall Fescue Leaves from Diverse Genotypes1

Abstract

Organic acids are important plant metabolites and have been associated with palatability and forage quality. Gas‐liquid chromatography was used to quantify nine organic acids in leaves of 22 genetically diverse tall fescue (Festuca arundinacea, Schreb.) genotypes grown in a greenhouse. Significant differences (p < 0.01) were found among genotypes in concentration of malic, citric, x‐ketoglutaric, succinic, malonic, quinic, shikimic, and total of the nine acids. Malic acid was most abundant in 19 genotypes and averaged 9.3 mg/g dry wt, followed by citric, succinic, quinic, and shikimic acids with 4.4, 3.6, 3.5, and 2.6 mg/g dry wt, respectively. Concentrations of fumaric and aconitic were usually less than 0.1 mg/g dry wt. A genotype selected from ‘Ky 31’' had 19.3, 6.6, and 38.8 mg/g dry wt of malic, citric, and total of the nine acids, respectively. In contrast, a genotype from Algeria had 3.5, 1.2, and 15.1 mg/g dry wt for the same fractions.Malic acid concentrations were positively correlated (p < 0.01) with quinic, shikimic, and citric acid levels. Succinic acid was positively correlated with a‐ketoglutaric acid, and shikimic acid was positively correlated with quinic acid. The genetic variability observed indicates organic acid content of tall fescue leaves could be altered through breeding.