Breeding low-glycemic index barley for functional food

Low glycemic index (GI) grains with high levels of 13 glucan soluble fibre are beneficial for health. Naked barley (Hordeum vulgare L) cultivars generally have higher grain p glucan contents than hulled barley, but lower yields. Naked grain requires no pearling or processing for use in wholegrain health foods and it is widely recognised that consumption of wholegrain barley is beneficial for health. Nearly all commercially available UK barley cultivars are hulled and have been bred for low (<3%) beta-glucan content for malting. In this study a large segregating population was made from crosses between diverse naked and hulled parents. Selections were made for naked barley lines with adaptation to UK cultivation that were >= 65% genetically similar to UK hulled barley. In a mapping population beta-glucan contents ranged from 1.4% to 8.6% with transgressive segregation occurring in both directions and no significant association of beta-glucan content with the gene for naked caryopsis (nud). A QTL explaining 31% of the inheritance of 13 glucan was detected on 7HL, approximately 15 cM above mid, and CslF6 is the most likely candidate gene. QTLs that can increase beta-glucan content and yield components that are not linked to hull type (nud) and row type (vrs1) can now be targeted to produce higher yielding functional food barley. Porridges made with selected naked barley and naked oats were tested for Gland the naked barley had significantly lower GI than oats, demonstrating that they can be incorporated in the diet as a functional food. (C) 2013 Elsevier B.V. All rights reserved.