Tolerance to Combined Stress of Drought and Salinity in Barley

Abstract

Drought and salinity, frequently co-occurring in both natural and agricultural ecosystems, are the most important abiotic stresses limiting agricultural production worldwide. Therefore, an improvement in drought and salinity tolerance in crops is a prerequisite for achieving economic gains. Barley, being one of the most tolerant cereal crops for drought and salinity, possesses tremendous potential as an ideal model crop for drought and salinity tolerance. Wild barley (Hordeum vulgare ssp. spontaneum or ssp. agriocrithum) was demonstrated as a key genetic resource for the tolerance to both stresses. Currently, plant morphology, physiology, and biochemistry have provided new insights to understand drought-tolerant traits. Improvement for drought and salinity tolerance can be achieved by the introduction of drought- and salt-tolerance-related genes and quantitative trait loci (QTLs) to modern barley cultivars. Therefore, the identification of candidate loci involved in drought and salinity tolerance using omics and QTL mapping is necessary. Drought/salinity-responsive genes and QTLs have been identified in both cultivated and wild barleys and have great potential for genetic improvement of barley. Combining tolerant genes and QTLs in crop-breeding programs aimed at improving tolerance to drought and salinity will be achieved within a multidisciplinary context. This strategy will lead to new cultivars highly tolerant to drought and salinity with high yield potential and stability in dry environments.