An integrated approach to evaluate and utilise genetic diversity for breeding climate-resilient barley

Summary
Barley is a major grain worldwide. Europe produces the greatest share (~60 MT/yr), of which ~20% underpins its brewing industry that generates annual government revenues of ~€ 50-60 bn and supports 150,000 farmers. Barley has potential as a health-promoting functional food, given its high content of sterols, stenols, arabinoxylans, and beta glucans.It is an important break crop and animal feed, and its straw has a role in animal welfare and nutrition, in bioenergy and in carbon capture. However, yield increase has flattened over recent years and future harvests are threatened by climate change. European agriculture anticipates a combination of stress factors, production threats and quality needs that breeders have not encountered before.

Climate-Smart Agriculture requires both the conservation of genetic resources and their effective use to develop regional varieties with sufficient resilience to deliver yield, quality and stability under increased and different seasonal stresses and decreased inputs.ClimBar will identify genome regions, genes, and alleles conferring the traits needed to breed resilient barley varieties adapted to the four climate change scenarios modelled for NE, NW, Mediterranean, and Central European grain producing zones by 2070. Resilience will require combining multiple traits and responses that include plant architecture, physiology, and metabolism.

These are determined by the unique allelic combinations that comprise the genome, the specific genomic marks of the epigenome, and their combined interactions with the external environment. CWRs (crop wild relatives) and landraces contain a vast pool of (epi-) genetic diversity and interactions naturally selected for resilience against local environmental pressures.

We will impose drought, flooding, temperature, and fungal challenges predicted to occur under each scenario and use precision phenotyping to measure the responses of a core representative set of modern and old varieties, landraces, and wild barley. Combined these genetic and phenomic data will provide a platform for incorporating both in situ and ex situ allelic diversity into programs for breeding increased resilience to climate change in barley, increasing genetic richness of the cultivar set, and forming a basis for multi-varietal cultivation.Adapted, resilient germplasm created using ClimBar data, tools and models will provide food-chain security, economic stability and environmental sustainability.