'Plant Breeding: Sustaining the Future' Abstracts of the XVIth EUCARPIA Congress, Edinburgh, Scotland, 10-14 September 2001 UNSATURATED FATTY ACID ANALYSIS – A TOOL IN WHITE CLOVER BREEDING FOR IMPROVED COLD HARDINESS Á. HELGADÓTTIR, S. DALMANNSDÓTTIR, R. P. COLLINS, M. ABBERTON The Agricultural Research Institute, Keldnaholt, 112 Reykjavík, Iceland

Lack of sufficient winter hardiness limits the use of commercial high yielding white clover cultivars in northern areas of Europe. A breeding programme is in operation to improve the winter hardiness of southerly cultivars by crossing them with populations adapted to more northerly environments. It has been suggested that improved winter hardiness is closely related to the production of unsaturated fatty acids, especially linoleic acid. These increase the fluidity of the cell membrane and thus make it less sensitive to environmental stress such as cold. Work is proceeding to identify molecular markers for the genes controlling levels of the most important unsaturated fatty acids using white clover mapping families developed at IGER, Wales. Such marker-assisted selection would be an effective pre-screening tool for the development of winter hardy cultivars.