Submitted to: International Journal of Food, Agriculture, and the Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/3/2012
Publication Date: 1/30/2012
Publication URL: http://handle.nal.usda.gov/10113/55031
Citation: Vantoai, T.T., Lee, J., Goulart, P., Shannon, G., Alves, D., Nguyen, H., Yu, O., Rahman, M., Islam, R. 2012. Soybean (Glycine max L. Merr) seed composition response to soil flooding stress. International Journal of Food, Agriculture, and the Environment. 10(1):795-804. Interpretive Summary: Soybean is a highly valuable commodity due to its high oil, protein and carbohydrate content. It is also highly regarded as nutritional and functional food due to its high monounsaturated fatty acid (oleic acid) and isoflavone content. While changes in soybean seed composition due to heat and drought stresses have been documented, the effects of flooding stress are not yet known. This study evaluated the effects of flooding on the seed composition of protein, oil, fatty acids and isoflavones in eight soybean germplasms with differing levels of flooding tolerance in three different field environments. The results showed that flooding increased oleic acid, the desirable, healthy fatty acid) to the greatest extent, followed by stearic acid in all genotypes, regardless of their flooding tolerance characteristics. The stress, however, affected tolerant and susceptible genotypes in different direction regarding other fatty acids and isoflavones: the stress reduced the levels of linoleic acid, linolenic acid, daidzein, genistein, and glycitein in the tolerant genotypes but increased them in the susceptible genotype PI086425. Contrary to drought stress, flooding did not affect seed protein, oil or palmitic acid. The novel results of this study provide information important in modeling soybean seed composition traits under flooding, a stress condition that is predicted to occur more frequently due to global climate changes.
Technical Abstract: Soybean is a valuable commodity due to its high oil and protein content and its nutritional and functional food value. Changes in soybean seed composition by environmental stressess including heat and drought have been documented, but the effects of flooding are not yet known. This study profiles the seed composition of eight soybean genotypes that differed in levels of flooding injury based on control and flooded conditions. The results showed that flooding did not significantly affect seed protein, oil or palmitic acid, but increased oleic acid and stearic acid levels in all genotypes. The levels of linoleic acid, linolenic acid, daidzein, genistein, and glycitein were significantly reduced in the tolerant and medium tolerant genotypes, but increased in the susceptible genotype. Seed quality index (SQI), a composite indicator of seed quality, was increased significantly by flooding but no correlation between the flooding response of SQI and flooding tolerance level was detected. These results provided information important in modeling soybean seed composition traits under flooding, a stress condition predicted to be more prevalent by global climate change.