Back to the future: Using ancient Bere barley landraces for a sustainable future

Societal Impact Statement: Bere is an ancient barley (Hordeum vulgare L.) that was once widely grown in northern Britain, where its ability to grow on poor soils and under challenging climatic conditions made it a valuable staple. By the end of the 20th century, Bere had largely been replaced by higher-yielding modern varieties and only survived in cultivation on a few Scottish islands. This article reviews the recent revival of Bere, driven by its use in high-value food and drink products and multidisciplinary research into its genetics, valuable sustainability traits and potential for developing resilient barley varieties. Summary: In Britain, modern cereal varieties have mostly replaced landraces. A remarkable exception occurs on several Scottish islands where Bere, an ancient 6-row barley (Hordeum vulgare L.), is grown as a monocrop or in mixtures. In the Outer Hebrides, the mixture is grown for animal feed, and cultivating it with traditional practices is integral to the conservation of Machair, an important coastal dune ecosystem. In Orkney, Bere is grown as a monocrop, and in situ conservation has recently been strengthened by improved agronomy and new markets for grain to produce unique foods and beverages from beremeal (flour) and malt. In parallel, a recently assembled collection of British and North European barley landraces has allowed the genotypic and phenotypic characterisation of Bere and several associated multidisciplinary studies. Genotyping demonstrated Bere's unique identity compared with most other barleys in the collection, indicating an earlier introduction to Scotland than the Norse settlement (c. 9th century AD) suggested previously. Valuable traits found in some Bere accessions include disease resistance, an early heading date (reflecting a short period from sowing to harvest), the ability to grow on marginal, high pH soils deficient in manganese and tolerance to salinity stress. These traits would have been important in the past for grain production under the region's challenging soil and Atlantic-maritime climatic conditions. We discuss these results within the context of Bere as a genetic, heritage and commercial resource and as a future source of sustainability traits for barley improvement.