Genotypic and environmental variation in soybean seed cell wall polysaccharides

Soybean [Glycine max (L.) Merr.] seed cell wall polysaccharides (CWP) have been characterized, but little is known about their genotypic variation. Th is information would be beneficial for determining genetic strategies for m anipulating CWP content and composition. Seed CWP was determined by the Upp sala total dietary fiber method to quantify monosaccharides of CWP in 14 so ybean genotypes from Maturity Groups 00 to I grown at four Minnesota locati ons. CWP concentration of mature whole seed varied from 158 to 176 g/kg dry matter (DM). Genotypic but not environmental effects were significant for total CWP concentration. For individual monosaccharide concentrations, both genotypic and environmental effects were present. Seed of five genotypes w ere separated into cotyledon and seed coat for CWP analysis. Genotypic vari ation for CWP concentration was mostly in cotyledon and not seed coat. Pect in was mostly in cotyledon rather than seed coat with 80.8 and 14.6 g pecti n/kg of whole seed DM in cotyledon and seed coat, respectively. Only xylose , glucose, galactose, and uronic acid concentrations were significantly dif ferent among genotypes in cotyledon. The correlation between CWP concentrat ion and protein plus oil concentration among the 14 genotypes was r = -0.72 4, which suggests that an increase in protein plus oil content is associate d with a reduction of CWP concentration. The genotypic variation observed s uggests that it is possible to breed for reduced CWP. However, genotypic va riation for some monosaccharides was limited, suggesting that other methods of genetic manipulation may be more efficient in reducing these monosaccha rides.