Ongoing climate change is resulting in increasing areas of salinity affected soils, rising saline groundwater and droughts resulting in irrigation with brackish water. This leads to increased salinity stress in crops that are already grown on marginal agricultural lands, such as barley. Tolerance to salinity stress is limited in the elite barley cultivar pools, but landraces of barley hold potential sources of tolerance due to their continuous selection on marginal lands. This study analyzed 140 heritage cultivars and landrace lines of barley, including 37 Scottish Bere lines that were selected from coastal regions, to screen for tolerance to salinity stress. Tolerance to salinity stress was screened by looking at the germination speed and the early root growth during germination, and the pre-maturity biomass accumulation during early growth stages. Results showed that most lines increased germination time, and decreased shoot biomass and early root growth with greater salinity stress. Elite cultivars showed increased response to the salinity, compared to the landrace lines. Individual Bere and landrace lines showed little to no effect of increased salinity in one or more experiments, one line showed high salinity tolerance in all experiments-Bere 49 A 27 Shetland. A Genome Wide Association Screening identified a number of genomic regions associated with increased tolerance to salinity stress. Two chromosomal regions were found, one associated with shoot biomass on 5HL, and another associated with early root growth, in each of the salinities, on 3HS. Within these regions a number of promising candidate genes were identified. Further analysis of these new regions and candidate genes should be undertaken, along with field trials, to identify targets for future breeding for salinity tolerance.
We thank Christine A. Hackett (BioSS) for statistical advice, and Amy Learmonth for guidance in the GWAS analysis. We would like to thank for the technical assistance of Carla De La Fuente Canto, Alison Dobson, Clare Macaulay, Malcolm Macaulay, and especially David Guy. We would also like to thank Joanne Russell for supervision and advice during the project and funding go to the Scottish Government’s Rural and Environment Science and Analytical Services (RESAS) for funding associated work by Adrian Newton and Timothy George.
This research was funded by the Agriculture and Horticulture Development Board (AHDB), through a Cereals and Oilseeds Ph.D. Studentship, and the James Hutton Institute.