1. Department of Horticulture, Swedish University of Agricultural Sciences, P.O. Box 103, SE-230 53 Alnarp, Sweden; Department of Agriculture—Farming Systems, Technology and Product Quality, Swedish University of Agricultural Sciences, P.O. Box 104, SE-230 53 Alnarp, Sweden; and Department of Plant Breeding and Biotechnology, Swedish University of Agricultural Sciences, Fjälkestadsvägen 459, SE-291 94 Kristianstad, Sweden