Evaluating Variation in Germination and Growth of Landraces of Barley (Hordeum vulgare L.) Under Salinity Stress

Abstract

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.

Back to the future: Using ancient Bere barley landraces for a sustainable future

“…Tolerance to salinity stress is limited in the elite barley cultivar pools and is becoming increasingly important as climate change results in larger areas of salinity-affected soil (Cope et al, 2022). In a study investigating tolerance to salinity stress (Cope et al, 2022), elite cultivars showed a greater adverse response to salinity compared with landrace lines, amongst which one Bere line from Shetland showed particularly high tolerance.…”

“…Research into traits in Bere that are likely to be of value to plant breeders has already identified adaptations to manganese-deficient soils (Cope et al, 2020;Schmidt et al, 2019), salinity (Cope et al, 2022) and resistance to the foliar disease Rhynchosporium commune (Cope et al, 2021) as being of potential value. Earlier research also indicated that some types of Bere may have tolerance to acidic soils (Ellis, 2003;Stølen & Andersen, 1978), and, considering the crop's association with sandy, coastal soils, some Bere accessions may also have tolerance to water-deficit (drought) conditions.…”