Compositional variability in conventional and glyphosate-tolerant soybean (Glycine max L.) varieties grown in different regions in Brazil

The compositions of a diverse range of commercially available conventional and genetically modified (GM; glyphosate-tolerant) soybean varieties from maturity groups 8 and 5, respectively, grown in the northern and southern soybean regions of Brazil during the 2007-2008 and 2008-2009 growing seasons were compared. Compositional analyses included measurement of essential macro- and micronutrients, antinutrients, and selected secondary metabolites in harvested seed as well as measurement of proximates in both forage and harvested seed. Statistical comparisons utilized a mixed analysis of variance model to evaluate the relative contributions of growing season, soybean growing region, production site, phenotype (GM or conventional), and variety. The study highlighted extensive variability in the overall data set particularly for components such as fatty acids, vitamin E, and isoflavones. There were few differences between the GM and non-GM populations, and most of the variability in the data set could be attributed to regional and variety differences. Overall, the results were consistent with the expanding literature on the lack of any meaningful impact of transgene insertion on crop composition.