Barley is a resilient crop that performs better than other cereal plants under abiotic stress
conditions, including salinity stress. The understanding of salinity tolerance in crops is a major
milestone to increase yield in areas affected by soil salinity. In barley, some components of
salinity tolerance have been elucidated, (e.g. HVP10, which is involved in tissue tolerance), yet
little research has explored the discovery of other components contributing to salinity tolerance.
In this PhD project, a forward genetics approach was used, whereby two barley populations were
phenotyped under controlled and field conditions for salinity tolerance. The first population is a
diversity panel of two-row European spring barley, and the second population is a nested
association mapping barley population with wild donors from the Fertile Crescent. The use of
non-destructive high-throughput experiments conducted under controlled conditions provided
insight into the understudied shoot ion-independent component of salinity tolerance. In
addition, the previously known association HvHKT1;5 was detected under controlled conditions.
In parallel, the field experiments increased our understanding of new components of salinity
tolerance, such as the maintenance of yield and yield-related traits under saline conditions.
This strategy was successful with the identification of a locus on chromosome 2H (140-145 cM),
where the allele from one of the wild donors of the nested association mapping population
increased yield under saline conditions in the field. When re-evaluating lines homozygous at the
2H locus, ear length, ear number per plant, yield and harvest index were all significantly higher
under saline conditions for the lines carrying the wild allele. Furthermore, another interesting
locus on chromosome 7H that was responsive to salt treatment and co-localized with HVP1 was
identified using the diversity panel population. Loci with known flowering genes were also shown
to be involved in salinity tolerance.
To conclude, this PhD project shed more light on the genetic mechanisms of salinity tolerance in
barley, a knowledge that can benefit breeding programs and can be extended to other crops such
as wheat.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/630115 |
| Date | 10 1900 |
| Creators | saade, stephanie |
| Contributors | Tester, Mark A., Biological and Environmental Sciences and Engineering (BESE) Division, Muehlbauer, Gary, Aranda, Manuel, Krattinger, Simon G. |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Dissertation |
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