HIGH-RESOLUTION GENETIC-MAP OF THE LV RESISTANCE LOCUS IN TOMATO

Bulked segregant analysis and high-resolution mapping were used to pin point the position of the Lu gene for resistance to Leveillula taurica in tomato. Mapping in an F-2, corresponding to more than 3800 gametes , indicates that Lv is positioned within the 0.84-cM interval defined by the RFLP markers CT121 and CT129, with the closest marker, CT121, b eing only 0.16 cM from the gene. The tight linkage of these markers de monstrates their usefulness in marker-assisted breeding for Lv, and th e high-resolution map provides a starting a starting point for positio nal cloning of this resistance gene.