Genetic diversity for seed mineral composition in the wild legume Teramnus labialis

Authors: Grusak, Michael

Submitted to: Plant Foods for Human Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2008
Publication Date: 9/2/2008
Citation: Grusak, M.A. 2008. Genetic diversity for seed mineral composition in the wild legume Teramnus labialis. Plant Foods for Human Nutrition. 63(3):105-109.

Interpretive Summary: Legumes are a large group of plants whose seeds are an important source of dietary nutrients for humans. Although many cultivated types are known, several wild legumes are also collected and consumed by rural and tribal populations throughout the world. Because the nutrient composition of these wild plants is not well understood, we studied one such legume, named Teramnus labialis, which is native to tropical regions. Fourteen diverse lines of this plant, originating from Asia, Africa, and Latin America, were used in the study. Plants were grown in a greenhouse and mature seeds were collected in order to analyze seed mineral concentrations. We found that this plant's seeds contained mineral concentrations that were comparable to several cultivated grain legumes, except for the minerals magnesium and potassium, which were higher in seeds of the wild plant. Our results suggest that efforts to develop Teramnus labialis into a cultivated food legume would be worthwhile.

Technical Abstract: Teramnus labialis is a wild, tropical legume whose seeds are collected and used as a food source by tribal populations. In order to assess the potential of this legume to provide dietary minerals for humans, fourteen diverse accessions were grown under controlled, nutrient-replete conditions and seeds were harvested for mineral analysis. The germplasm originated from Indonesia, Africa, the Caribbean, and South America. Seed concentrations of calcium (Ca), phosphorus (P), sodium (Na), iron (Fe) copper (Cu), manganese (Mn), zinc (Zn), and nickel (Ni) were found to fall within the range of published values for several cultivated grain legumes, while magnesium (Mg) and potassium (K) were higher in Teramnus labialis seeds. Mineral concentrations across the diverse accessions showed ranges of 1.3- to 1.7-fold for the macronutrient minerals (Ca, Mg, P, K) and 1.6- to 5.6-fold for the micronutrient minerals (Fe, Cu, Mn, Zn, Ni, and Na). The existing genetic diversity in this wild legume, especially for the essential minerals Mg and K, could be exploited to develop Teramnus labialis as a new cultivated legume for tropical regions of the world.