Molecular tagging

Septoria leaf spot caused by Septoria lycopersici Speg. and late blight caused by Phytopthora infestans (Mont.) de Bary are two important foliar diseases of tomato (Solanum lycopersicum L.). Identification of DNA markers linked to these diseases is a prerequisite for accelerating resistance breeding through marker-assisted selection (MAS). The objectives of the present study were to investigate the inheritance pattern of septoria leaf spot resistance and identify molecular markers linked to septoria leaf spot and late blight resistance in tomato. The inheritance of resistance to septoria leaf spot was based on a single dominant gene. Transgressive segregation for resistance and susceptibility to late blight was also observed. Out of the 34 RAPD polymorphic markers 11 primers (32.35%) were polymorphic between resistant and susceptible bulks of septoria leaf spot and 16 (47%) produced polymorphic bands between resistant and susceptible bulks of late blight lines.