Effects of environment and variety on content and molecular weight of β-glucan in oats

Oat beta-glucan has been shown to have cholesterol, insulin and glucose lowering effects, which are related to increased viscosity of the intestinal contents. Some important factors influencing the viscosity are molecular weight, structure and concentration. To study the effect of variety and environment on beta-glucan content and molecular weight of beta-glucan, four oat varieties were grown in 11 different environments (location x year combinations) in a field experiment. The beta-glucan content varied between 2.3 and 3.2% and the average molecular weight of beta-glucan between 1.73 and 2.02 x 10(6) g mol(-1). There was a significant difference between varieties and environments for both beta-glucan content and molecular weight of beta-glucan. The effect of environment was much greater on molecular weight (71%) than on beta-glucan content (42%), while the effect of variety was greater on beta-glucan content (23%) than on molecular weight (4%). There was also a positive significant correlation between beta-glucan content and molecular weight of beta-glucan (p < 0.001, r = 0.46). These results show that beta-glucan content is a better target for plant breeding than molecular weight. However, both factors are important for the physiological effects of beta-glucan, and selection for high beta-glucan content will probably also give higher molecular weight. (C) 2011 Elsevier Ltd. All rights reserved.