... based on a single dominant gene (Lebeda and Pink, 1998; pers.comm., S. McClement, HRI, UK).During the last two decades, researchers and breeders have been increasinglyinterested in the exploitation ... and Boukema, 1991; Lebeda and Reinink,1994; Lebeda and Pink, 1998; Reinink, 1999). Several studies showed that wild speciesmay possess a new and very interesting resistance to B. lactucae (Lebeda ... seedling stage are included in this table. However, some genotypes (e.g.PI 281876, LVIR/57/1) express incomplete incompatibility if tested as leaf discs fromadult plants (Lebeda and Reinink,...