Stability of Soluble Sugars in Soybean Seed Under Different Environments.

The total sugar content in soybean cultivars plays an important role in the production of soy-based products because of its influence on quality and sensory. Sucrose is the primary soluble carbohydrate (40-68%) in mature soybean seeds, followed by smaller amounts of stachyose and raffinose; fructose, glucose, and galactose are considered minor sugars accounting for 4 to 13.2% of the soluble sugars. The objectives of this study were to evaluate the genotype by environment interaction on soluble sugar contents, and to determine heritability and possible correlations among sugars and other quality traits. Twenty three soybean genotypes with specific quality trait profiles were selected to represent an array of differences in sugar, protein, oil, and seed size. Two commercial checks commonly used for oil-crushing were also included. The experiment was conducted in a Randomized Complete Block (RCB) design with two replications at four different Arkansas locations, planted in 2007 and 2008. Contents of glucose, fructose, sucrose, raffinose, and stachyose were separated and quantified with a High Performance Chromatography (HPLC) System from a sample of 10g of soybean seed. Also, other quality traits, including seed size, oil and protein content, hardness, and mineral composition were assessed. Partial results suggest significant differences among locations for some of the sugar contents studied. No correlations were found among sucrose, raffinose, and stachyose; between raffinose and oil; and between protein and raffinose, and protein and stachyose. Weak negative correlations between sucrose and oil were found. The final data set analysis will be presented to validate these results.