Wheat and Barley Biology: towards new frontiers.

Among the approx. 30 genera and 360 species belonging to the tribe Triticeae (subfamily Pooideae, family Poaceae), wheat (Triticum ssp.) and barley (Hordeum vulgare L.) are economically the most important temperate cereal crops. On a global scale in 2016, wheat was ranked second (749 million tons) and barley fourth (141 million tons) in terms of world production (FAO STAT, 2018). A considerable amount of our daily carbohydrates and proteins is contributed by both species. Cereals and bread are the major source of energy for all age groups, providing ∼30% for adults in developed countries, while it can be up to 80% in developing countries (Shewry and Hey 2015). Despite their global importance for food security and supply, yield gains of wheat and barley have remained rather moderate or stagnant within the last two decades, specifically in the high-yielding areas of the world such as Europe (Ray et al. 2012; Grassini et al. 2013). Clearly, this alarming trend has to change, to ensure that future projected food demands can be met in a sustainable manner (Tilman et al. 2011; Garnett et al. 2013).