Vattenmättnadstolerans allt viktigare i korn

Barley is very sensitive for waterlogging which causes yield reduction worldwide and so also in the Nordic countries. The problems are expected to increase as a result of climate changes. Thus more tolerance for waterlogging is needed, but there is a lack of efficient selection methods to use in breeding. In this project a rapid, efficient and inexpensive method has been developed and used for the characterisation of 175 Nordic barley cultivars, a group of breeding lines and a DH-population used for identification of QTL markers. In the described method hydroponics with low aerated nutrient solutions are used to simulate waterlogging conditions in soils. Using a Mini-PAM, the quantum yield from stressed plants is measured and this is showed to be correlated with the growth reduction of plants in waterlogged soil. The characterisation of barley cultivars revealed that waterlogging tolerance has been unintentionally improved during the last 30 years when breeding for increased yield. However, the study of a breeding material showed that there are unutilized gene resources still to be used. A characterisation of a marker population, and the following genotyping using SNP markers, revealed five QTL that explained 74 % of the variance in QY. This opens a possibility to use DNA-markers in breeding for improved waterlogging tolerance. While not only waterlogging tolerance can be improved, probably also other tolerance against drought and salt can increase, resulting in higher and more stable grain yields.