Affiliation: | Plant Research Department, RisøNational Laboratory, PO Box 49, DK-4000 Roskilde, Denmark;;Department of Microbiology, Biological Institute, University of Copenhagen, Øster Farimagsgade 2D, DK-1353, Denmark;;Agricultural Research Centre of Finland–MTT, Laukaa Research and Elite Plant Station, Antinniementie 1, FIN-41330 Vihtavuori, Finland |