Genotype, environment and G × E interaction influence (1,3;1,4)-β-d-glucan fine structure in barley (Hordeum vulgare L.).

Background: The structure of β-glucan influences its use in cereal-based foods and feed. The objective of this study was to determine the effect of environment (E) and genotype (G) on β-glucan fine structure and its genetic control in two-row spring barley with normal starch characteristics.
Results: A population of 89 recombinant inbred lines, derived from the cross of two-row spring barley genotypes Merit × H93174006 (H92076F1 × TR238), was characterized for concentration and structure of grain β-glucan in two environments. Results showed that concentrations of β-glucan, DP3, DP4 and DP3 + DP4 were positively correlated with each other, suggesting no preference for DP3 or DP4 subunit production in high- or low-β-glucan lines. The concentrations of β-glucan, DP3, DP4 and DP3:DP4 ratios were significantly influenced by genotype and environment. However, only DP3:DP4 ratio showed a significant effect of G × E interaction. Association mapping of candidate markers in 119 barley genotypes showed that marker CSLF6_4105 was associated with β-glucan concentration, whereas Bmac504 and Bmac211 were associated with DP3:DP4 ratio. Bmac273e was associated with both β-glucan concentration and DP3:DP4 ratio.
Conclusion: The grain β-glucan concentration and DP3:DP4 ratio are strongly affected by genotype and environment. Single-marker analyses suggested that the genetic control of β-glucan concentration and DP3:DP4 ratio was linked to separate chromosomal regions on barley genome. © 2016 Society of Chemical Industry.
(© 2016 Society of Chemical Industry.)