Mucilage is a hydrogel formed from polysaccharides released from imbibed Arabidopsis seeds. These polysaccharides are accumulated in the epidermal cells of the seed coat during seed development. The role of this mucilage remains to be determined, but its absence is not detrimental in laboratory conditions, making it an excellent model for the study of polysaccharide properties. We have previously shown that Arabidopsis mucilage is formed of a mixture of polysaccharides in two structurally distinct layers, both of which are mainly composed of the pectin rhamnogalacturonan I. In a previous project, biochemical data were obtained from 301 Arabidopsis natural variants concerning the natural variation in outer mucilage physicochemical properties (Tran et al., unpublished). Low-field NMR spectroscopy was developed for the characterization of water uptake into seeds during imbibition, based on T2 relaxation times assigned to water mobility in the different mucilage layers (Saez-Aguayo et al., 2014). The work presented here will focus on low-field NMR applied to the characterization of the physicochemical properties of the inner layer for 19 selected accessions. Eighteen of these genotypes have particularly divergent characteristics compared to the Col-0 reference accession. For each seed, T2 relaxation times were measured and correlations identified with regard to the sugar composition of the inner and outer layers, and the width of the inner layer.