Desmodium genetic resources for improving flavonoid concentrations, oil content and fatty acid compositions

Abstract

Several Desmodium species are adapted to the environment of Griffin, Georgia, USA. The determination of flavonoid concentrations, oil content and fatty acid compositions of 25 Desmodium accessions representing five species (D. discolor Vogel, D. incanum (G.Mey.) DC., D. intortum (Mill.) Urb., D. sandwicense E. Mey. and D. tortuosum (Sw.) DC.) would add value to the members of the genus Desmodium for possible use as livestock health supplements. In this study, the seeds of these 25 accessions were evaluated for flavonoid concentrations, oil content and fatty acid compositions using high-performance liquid chromatography, nuclear magnetic resonance and gas chromatography, respectively. Several accessions exhibited significantly greater values for all the traits than the controls. The Desmodium accessions produced significantly greater concentrations of quercetin and kaempferol than the best control accession (D. incanum, PI 477072). However, all the Desmodium accessions produced significantly greater concentrations of isorhamnetin and luteolin than the control accessions. All the Desmodium accessions had greater linoleic (18:2) and behenic (22:0) acid content than a couple of D. incanum control accessions in 2010 and 2011. Significant correlations were observed between several traits. The concentration of quercetin was significantly correlated with that of kaempferol (r2= 0.69***); however, the concentration of quercetin exhibited a significantly negative correlation (r2= − 0.41*) with that of isorhamnetin. Oil content was significantly correlated with palmitic acid (r2= 0.61**), stearic acid (r2= 0.81***), linolenic acid (r2= 0.58**) and lignoceric acid (r2= 0.80***) content. This information will assist breeders and other scientists in developing superior cultivars with optimum levels of flavonoid concentrations, oil content and fatty acid compositions for many of these Desmodium species.