Improving Drought and Heat Stress Tolerance In Wheat and Barley

Abiotic stresses including high and low temperatures, low water, intense light, salinity, and deficiencies or toxicities for a range of nutrients can severely reduce crop plant productivity. Multiple abiotic stresses will frequently challenge crop plants simultaneously. Higher plants have evolved multiple, interconnected strategies that enable them to survive unpredictable environmental fluctuations. However, these strategies are not always well developed in the cereal cultivars and most of the strategies studied in model species are focused on plant survival which can often be at the expense of yield.

For the cereals wheat and barley the genetic control of traits determining yield in water limited and low yielding environments are generally expected to be of low heritability, polygenic and many of the key loci will show epistatic rather than additive effects.  Current breeding and mapping techniques make it very difficult to detect and select for these types of loci.  Know confounding factors, such as maturity, height, resistance or tolerance to soil diseases, and tolerance to related stresses such as boron, acidity, salinity and nutrient deficiencies must be taken into account.  In some cases the genetic control of tolerance to these confounding factors is known so that they could be fixed in both breeding and mapping populations.

A broad approach to using genomics techniques and new phenotyping tools to tackle abiotic stress tolerance in wheat and barley will be presented with some specific examples of how these results can be deployed.